Pakistan Journal of Analytical & Environmental Chemistry
Pakistan Journal of Analytical & Environmental Chemistry is biannual publication by National Centre of Excellence in Analytical Chemistry, University of Sindh, Jamshoro. Journal covers fields of pure and applied analytical chemistry, environmental, material, agricultural and food chemistry, geochemistry, biotechnology, pharmaceutical and biomedical sciences, development and modification of instruments and techniques with potentials in environmental sciences. The Journal started publishing in year 2000 with the title, 'Pakistan Journal of Analytical Chemistry', later title was changed to its current in the year 2006. ISSN: 1996-918X; E-ISSN:2221-5255.
National Centre of Excellence in Analytical Chemistry, University of Sindh
Indirect Voltammetric Method for the Determination of Amino Acids Via Charge Transfer Complex Formation Reaction
An easy and sensitive indirect voltammetric method has been proposed for the determination of trace amounts of amino acids, such as proline, glycine, arginine, phenylalanine, glutamic acid, and cysteine, in the range of 50–330 ngmL-1 in aqueous solution. It is based on the reaction of chloranil as a π-acceptor with the intended amino acids acting as n-donors, forming an n–π charge transfer complex at pH 9. The reduction peak of (pH 9 – chloranil) solution appears at 0.030 V against the Ag/AgCl. reference electrode. When an aqueous solution of amino acids is added, the peak of solution (pH 9 – chloranil) decreases quantitatively and shifts slightly to 0.024 V. The concentration of amino acids is determined as the current difference decreases. The molar absorptivity ranges between 4.73 ×103 l/mol.cm and 1.82 ×104 l/mol.cm. The accuracy, i.e. average recovery ranges from 98.64% to 101.19%, and the precision, i.e. relative standard deviation (RSD) is between 0.5% and 9.6%. The limit of detection (LOD) ranges from 1.09×10-7 µg/ml to 3.53×10-7 µg/mL.
Amino acids, Charge transfer complex, Square wave voltammetry
Copyright (c) 2026 Pakistan Journal of Analytical & Environmental Chemistry https://creativecommons.org/licenses/by-nc-sa/4.0
PVP-Directed MOF-Derived Fe–N–C Catalysts: Toward High-Performance and Sustainable PEM Fuel Cell Cathodes
The urgent need to reduce carbon emissions and transition toward cleaner energy systems has intensified the search for electrocatalysts that are both efficient and resource-sustainable. Proton exchange membrane fuel cells (PEMFCs), powered by the oxygen reduction reaction (ORR), represent a key technology in this shift, but their reliance on platinum-group metals (PGMs) limits large-scale deployment. Single-atom Fe–N–C catalysts have emerged as promising PGM-free alternatives in acidic electrolytes, offering a balance of performance, cost, and environmental benefits. In this study, we report Fe-N-DPC-1000, an iron- and nitrogen-doped porous carbon synthesized at 1000 °C through a polyvinylpyrrolidone (PVP)-assisted metal–organic framework (MOF) strategy. The introduction of PVP during precursor formation promotes nitrogen incorporation, ensures atomic-level Fe dispersion, and stabilizes the framework during pyrolysis. The resulting material exhibits a hierarchical micro–mesoporous structure with a BET surface area ~ 1580 m²g⁻¹ along with a micropore volume of 0.54 cm³g⁻¹. Single-cell PEMFC testing demonstrated a peak power density of 1205 mWcm⁻², approaching the level of Pt/C performance and outperforming its PVP-free counterpart by 35.3%, while maintaining strong stability. These results establish polymer-assisted MOF engineering as a scalable approach to designing highperformance Fe–N–C catalysts for next-generation, environmentally sustainable fuel cell technologies.
Proton Exchange Membrane Fuel Cells (PEMFCs)
Platinum-Group-Metal-Free (PGM-Free) Catalysts
Proton exchange membrane fuel cells (PEMFCs), Oxygen reduction reaction (ORR), Platinum-group-metal-free (PGM-free) catalysts, Fe–N–C catalysts, Sustainable energy conversion.
Serum Copper Homeostasis and Its Relationship with Iron Deficiency Anemia in Children
Copper-dependent ferroxidases are required for cellular iron export, but local pediatric data on copper status in iron deficiency anemia (IDA) are limited. This comparative cross-sectional study evaluated serum copper homeostasis in 300 children aged 1-15 years at Civil Hospital, Ghulam Muhammad Mahar Medical College, Sukkur, Pakistan. The study included 150 biochemically confirmed IDA cases and 150 age-matched healthy controls. Complete blood count, serum iron, ferritin, and copper were measured using validated hematological and biochemical procedures; serum copper was estimated by a bathocuproine-based method on the ADVIA 1800 Chemistry analyzer with trace-element-aware sample handling. Children with IDA showed significantly lower mean serum copper than controls (86.34 ± 0.83 vs 120.41 ± 1.02 µg/dL; P < 0.001). Serum iron (63.71 ± 1.54 vs 105.80 ± 1.52 µg/dL) and ferritin (8.57 ± 2.14 vs 35.68 ± 4.89 ng/mL) were also significantly reduced. Within the IDA group, serum copper correlated positively with serum iron (r = 0.52; P < 0.001) and ferritin (r = 0.49; P < 0.001). These findings indicate disturbed copper homeostasis accompanying pediatric IDA and support selective copper assessment in severe, recurrent, or treatment-resistant cases.
Serum copper; iron deficiency anemia; ferritin; children
Two Validated Spectrophotometric Methods for Quantitative Analysis of Amlodipine Besylate in Pharmaceutical Preparations by Redox Reaction
This research aims to develop two spectrophotometric methods for the quantitative determination of amlodipine besylate (ADB) in its pure form and in pharmaceuticals. Both methods are characterized by simplicity, high accuracy, sensitivity, cost-effectiveness, and eco-friendliness. The underlying principle for both techniques is based on redox reactions. The first method (indirect) involves the reaction of ADB with a known excess of N-bromosuccinimide (NBS) in an acetic acid medium. The residual NBS is subsequently determined by its ability to bleaching the color of Orang G dye, with the remaining dye measured at λ max = 478 nm. The second method (direct) entails the reduction of potassium permanganate by ADB in an alkaline medium, resulting in the formation of a bluish- green manganate ion (MnO42-) which exhibits maximum absorbance at λ max = 608 nm. Linearity for the two methods was observed in the ranges 1-35 and 1-70 µg. mL-1, with determination coefficients (R2) of 0.9989 for each method. The molar absorptivity values were 2.166 ×104 and 0.98 ×104 L.mol-1.cm-1, while Sandell’s sensitivity index values were 0.0262 and 0.058 µg.cm-2, respectively. The limit of detection (LOD) was found to be 0.196 and 0.567 µg.mL-1, while the limit of quantification (LOQ) was 0.653 and 1.89 µg.mL-1, respectively. The proposed methods were effectively applied to evaluate ADB in pure forms and pharmaceutical preparations (tablets, capsules). The validity of these methods was confirmed through recovery studies using the standard addition method.
Amlodipine besylate, Spectrophotometric, Determination, Orange G, Redox -Reaction
Environmental Fate, Plastisphere Microbial Dynamics, and Human Health Implications of Marine Micro- and Nanoplastics
Micro- and nanoplastics are now widely recognized as contaminants of marine environments, with increasing concern about their potential effects on ecological and human health. Due to their small size, persistence, and high surface-area-to-volume ratio, these particles can interact with a large number of matrices in the environment and biological systems. Plastic particles quickly get covered by various microbial communities in water bodies to form complex structures known collectively as the plastisphere. These assemblages of microbes may influence how plastics behave in the environment and could help transport microorganisms and chemical contaminants across marine ecosystems. This review summarizes what is known about where micro- and nanoplastics are found in the environment, how they interact with microbial communities, and what their ecological and toxicological effects are. More detail is provided about the formation of plastispheres, the succession of microbes on plastic surfaces, plastic particles as vectors for pathogens and toxic substances. The review also looks at new evidence that links exposure to microplastics with oxidative stress, inflammatory responses, endocrine disruption, and changes in gut microbial communities in aquatic organisms—and perhaps even in humans. Finally, it discusses new developments and analytical challenges related to the detection and characterization of micro- and nanoplastics from environmental samples. Though substantial progress has been made, there are still significant knowledge gaps regarding standardized analytical methods for chronic exposure thresholds as well as mechanistic toxicology for nanoplastics. Overcoming these challenges through interdisciplinary research and enhanced environmental monitoring will be critical for improving risk assessment efforts aimed at reducing plastic pollution in marine ecosystems.
Marine Microbiology, Ecotoxicology, Environmental Health, Food Web Contamination and Risk Assessment
Ecotoxicology, Marine Ecology and Environmental Chemistry
AI-Driven Frameworks and Sensor-Robotic Networks for Urban Waste Management: A Systematic Review Toward Sustainable Smart Cities
This study presents a systematic and quantitative review of artificial intelligence (AI) applications in modern waste management systems, with a focus on environmental chemistry, process optimization, and sustainability outcomes, supported by quantitative performance comparisons from recent literature. The review systematically evaluates AI-driven approaches across the entire waste lifecycle, including generation, monitoring, sorting, transportation, recycling, energy recovery, and final disposal. Emphasis is placed on machine learning (ML), computer vision, robotics, and wireless sensor networks for improving operational efficiency, cost reduction, and environmental performance. The analysis highlights recent advances in AI-assisted waste chemistry, including carbon emission prediction using FTIR-ML hybrid models, optimization of anaerobic digestion and biogas generation, and predictive modeling of plastic pyrolysis processes for hydrogen and biofuel recovery. AI-based surveillance systems using Convolutional Neural Networks (CNNs), Unmanned Aerial Vehicles (UAVs), and satellite data demonstrate high accuracy in illegal dumping detection and spatial waste monitoring, with reported classification accuracies exceeding 90-98% in several studies. Quantitative comparisons indicate improvements in collection efficiency, recycling accuracy, and cost reduction relative to conventional methods, with reported efficiency gains of approximately 20-40% and operational cost reductions ranging from 15-30%, depending on system scale. However, the review identifies critical limitations, including data scarcity, model interpretability challenges, high computational cost, and the “reality gap” between laboratory datasets and real-world waste conditions. The findings indicate that isolated AI solutions often fail to achieve scalable and context-adaptive performance due to fragmentation, limited data integration, and a lack of environmental feedback mechanisms. This study uniquely proposes a unified cyber-physical-environmental framework that integrates sensing, AI analytics, and environmental feedback mechanisms across the urban waste management lifecycle. The study concludes that integrated, explainable, and hybrid AI frameworks are essential to enable scalable, context-aware, and policy-relevant waste management systems. Such systems can significantly support circular economy strategies, climate change mitigation, and public health protection in rapidly urbanizing regions.
Enhanced Adsorptive and Photocatalytic Degradation of Synthetic Melanoidin Using Silver-Doped TiO₂ Nanoparticles
Herein, silver-doped titanium dioxide nanoparticles (Ag-TiO2 NPs) were synthesized via a solution based sol-gel method followed by calcination at 450 oC for 2 h and were utilized in the treatment of synthetic melanoidin solution (SMS). The structural and morphological characterization, conducted through X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDX), Fourier-transform infrared spectroscopy (FTIR), and Ultraviolet-visible (UV–Vis) spectroscopy, confirmed the successful integration of silver within the TiO₂ matrix. Ag-TiO₂ NPs showed improved physicochemical properties, such as a reduced band gap of 2.8 eV, as compared to undoped TiO₂. When exposed to visible light (λ > 400 nm), Ag-TiO2 NPs decolorized SMS by more than 85% in 180 min at pH 7 and an initial melanoidin concentration of 200 mg/L. Also, chemical oxygen demand (COD) and total organic carbon (TOC) were significantly reduced to 60% and 40%. The conversion of recalcitrant melanoidin into more biodegradable byproducts was confirmed by the significant improvement in the biodegradability index (BOD5/COD) from 0.1 to 0.3. The stability of the catalyst was confirmed through reusability testing, color removal efficiency ranged between 85% to 75% after five cycles. According to kinetic studies, the principal mechanism of degradation is surface-mediated melanoidin adsorption followed by plasmon-induced charge separation, which promotes the production of reactive oxygen species and preserves catalytic performance by lowering surface fouling. Collectively, these findings underscore Ag-TiO2 NPs as a robust, reusable, and ecologically sustainable solute ion for large-scale melanoidin-rich industrial effluents.
Silver-doped TiO2 nanoparticles (Ag-TiO₂ NPs), Synthetic melanoidin solution (SMS), Visible-light photocatalysis, Photocatalytic degradation
Copyright (c) 2025 Pakistan Journal of Analytical & Environmental Chemistry https://creativecommons.org/licenses/by-nc-sa/4.0
Development and Validation of Indirect Spectrophotometric Methods for Assessing Levofloxacin in Pure and Pharmaceutical Formulations
Two simple, sensitive, and economical indirect spectrophotometric methods were developed for the determination of levofloxacin (LEVX) in the pure form and pharmaceutical preparations. The first proposed method (A) involved oxidation of LEVX using an excess amount of N-bromosuccinimide (NBS) under acidic conditions. Once the reaction was complete, the residual NBS was determined by shortening the color of Orange G (OG) dye, with the absorbance of the remaining dye measured at 476 nm. The second proposed method (B) is also based on the oxidation of LEVX using a fixed excess amount of NBS in an acidic environment. The excess NBS then reacts with p-Anisidine (P-AN), producing a violet-coloured brominated product. The intensity of the resulting colour, measured at 518 nm, is inversely proportional to the amount of LEVX present in the sample. Linear calibration curves were obtained for both methods within the concentration ranges of,0.5 – 10.5 and 1.0 – 15.0 μg.mL-1, respectively, with correlation coefficients of 0.9990 and 0.9992. The molar absorptivity values were 4.17×104 and 2.92×104 L.mol-1.cm-1 for methods A and B, respectively. Whereas, Sandell’s sensitivity index values were 0.00867 and 0.0123 μg.cm-2, respectively. The limits of detection (LOD) were 0.014 and 0.46 μg.mL-1, and the limits of quantification (LOQ)were 0.12 and 0.40 μg.mL-1 for methods A and B, respectively. The proposed methods were effectively used to estimate LEVX in available dosage forms, and their validity was confirmed through a recovery study using the standard addition method.
Levofloxacin, Spectrophotometric, N-Bromosuccinimide, Orange G, P-Anisidine
Morphology and Filtration Characteristics of a Polysulfone Hollow Fiber Membrane
Polysulfone (PSF) hollow fiber membranes incorporating a asymmetric microstructures suitable for ultrafiltration, were fabricated using dry–wet phase inversion method. The optimized dope solution contained PSF (25 wt%), polyethylene glycol (PEG-400; 22 wt%), and polyvinylpyrrolidone (PVP-K90, Mw ≈ 1,300 kDa; 0.3 wt%) dissolved in N,N-dimethylacetamide (52.7 wt%). The extruded nascent fibers coagulated in deionized water to form membranes with a dense selective skin layer supported by a porous substructure. Fourier Transform Infrared Spectroscopy (FT-IR) analysis confirmed the presence of the characteristic sulfone functional groups, indicating the chemical stability of the PSF matrix. Scanning Electron Microscopy (SEM) revealed a well-defined lumen structure with a diameter of 1.09 ± 0.05 mm and a wall thickness of 0.20 ± 0.01 mm. The membrane cross-section showed distinct finger-like macrovoids. These extended throughout the structure, indicating effective phase inversion and stable morphology. The membrane exhibited a porosity of 48.8 ± 2.1% and a pure water permeance of 70 ± 5 L m⁻² h⁻¹ bar⁻¹. The evaluation of ultrafiltration performance was done using bovine serum albumin (BSA, Mw ≈ 66 kDa). The membrane showed a rejection rate of 95 ± 1% at 2 bar pressure. This confirms its effective size-exclusion capability. Compared with reported PSF flat-sheet membranes, the present hollow fiber configuration demonstrated a more favourable balance between permeability and selectivity, attributed to PEG-400-driven rapid demixing and PVP induced pore interconnectivity. These findings showcase the potential of this minimalist dualadditive formulation for scalable, high-performance PSF hollow fiber membranes in aqueous separation applications.
polysulfone hollow fiber membrane, PEG-400, PVP, phase inversion, morphology, ultrafiltration
Analytical Method Development and Validation of High-Performance Liquid Chromatography for Simultaneous Determination of Ibuprofen and Baclofen
Combining baclofen with ibuprofen offers synergistic pain relief by targeting both muscle spasms and inflammation, enhancing efficacy in managing musculoskeletal conditions. This study aims to develop and validate an analytical method for the separation and simultaneous determination of ibuprofen and baclofen in combination using high-performance liquid chromatography (HPLC) in pharmaceutical dosage forms. An HPLC analytical method was developed to simultaneously quantify ibuprofen and baclofen. The optimized method was validated in accordance with the International Conference on Harmonization (ICH) guidelines. The method was tested for validation parameters, including specificity, accuracy, precision, linear range, limit of detection, lower limit of quantification, and robustness. A simple HPLC method was developed to separate two active ingredients using a C18 stationary phase column (25 cm × 0.46 cm, 5 μm). The mobile phase consisted of methanol: buffer (pH 3 ± 0.05), and acetonitrile in a ratio of 5:30:65 (%v/v). The analysis was performed at 25 °C with a 1.5 mL/min flow rate. A 20 μL sample volume was injected and detected at 265 nm. The validation method was specific, precise, and accurate. The average recovery of the two ingredients was 100.5% [99.1-102.0]. The repeated tests of the two compounds at different concentrations showed a percentage relative standard deviation (%RSD) of less than 1%. The method demonstrated linearity for both ibuprofen and baclofen, with an R² value of 0.99. The linearity range was 12.5-150 μg/mL for baclofen, and was 100-1800 μg/mL for ibuprofen. The lower limit of quantification (LLOQ) was 7 and 6 μg/mL for ibuprofen and baclofen, respectively. The limit of detection (LOD) was 2 μg/mL for both ingredients. The developed method is simple, rapid, precise, and accurate. It can be used for routine analysis of a combination of ibuprofen and baclofen in pharmaceutical dosage forms.
HPLC, Ibuprofen, Baclofen, Validation, ICH, Pharmaceutical dosage
Time-course Cellulase Production by B2S8 Bacterial Isolate and Its Utilization in Bioethanol Fermentation from Corn Stover
Cellulase enzymes play crucial roles in hydrolyzing cellulose into simple sugars, which potentially serve as substrates for bioethanol production. These enzymes can be sourced from cellulolytic bacteria, which are characterized by exhibiting different growth and enzyme production patterns. This study was aimed to determine the cellulase activity of B2S8 bacteria previously isolated from compost products, followed byoptimization oftheir application for bioethanol fermentation. The research was conducted in two stages: examination of the effect of incubation time on bacterial growth and enzymatic activity within 144 h divided into 19 levels, and the second stage was to optimize fermentation conditions using a factorial randomized block design with two factors: crude cellulase enzyme concentration (7, 9, and 11% v/v) and fermentation temperature (30, 35, and 40 °C). The results of the first stage showed that incubation time significantly influenced the optical density of bacterial culture measured at 660 nm (OD660), pH, and enzyme activity. The highest enzyme production was observed at 72 h, with OD660 2.4, pH 7, endoglucanase activity 0.097 IU/mL, exoglucanase activity 0.018 IU/mL, soluble protein 0.0363 mg/mL, and specific activities of 2.906 IU/mg and 0.018 IU/mg of endoglucanase and exoglucanase, respectively. The following optimization study revealed that the combination of 9% (v/v) enzyme concentration and fermentation at 35 °C yielded the highest ethanol content (0.50 ± 0.07% v/v), with a resulting pH of 4.85 ± 0.07, total soluble solids of 3.4 ± 0.07 °Brix, and reducing sugars value of 0.802 ± 0.03 °Brix. In this work, isolate B2S8 demonstrated promising cellulase production and effective application in bioethanol fermentation, which indicates its potential for further development in bioconversion processes.
B2S8 Isolate, Bioethanol, Cellulolytic Bacteria, Corn Stover, Growth Characteristic.
Synthesis and Sorption Performance of Pyridyl-Based Imine and its Homocyclic Analogue toward Ni(II) and Cd(II) Ions in Aqueous Solution
Nickel and cadmium are toxic heavy metals that pose serious environmental and health concerns due to their persistence and bioaccumulation. It commonly enters aquatic systems through industrial effluents, electroplating, mining, and the disposal of Ni-Cd batteries. Developing efficient sorbents for their removal from water is therefore of great importance. In this study, two imine derivatives were synthesized and evaluated as sorbents for Ni(II) and Cd(II) ions. The first derivative, 3,3′-dimethyl-[1,1′-biphenyl]-4,4′-diyl-bis-(1-(pyridin-2-yl) methanimine) (SB-1), was obtained from aryl diamine and pyridine-2-carboxaldehyde, while the second, 3,3′-dimethyl-[1,1′-biphenyl]-4,4′-diyl-bis-(1-phenylmethanimine) (SB-2), was synthesized using benzaldehyde. Both compounds were characterized by UV–Vis, FT-IR, FAB-MS, and ¹H-NMR spectroscopy. Batch adsorption experiments showed that SB-1 achieved maximum adsorption capacities (Qmax) of 16.89 mg/g for Ni(II) and 8.05 mg/g for Cd(II), while SB-2 recorded 12.66 mg/g and 7.42 mg/g, respectively, indicating higher efficiency of SB-1. The Langmuir model best described the adsorption data, suggesting monolayer adsorption on homogeneous surfaces, and RL values confirmed favorable sorption. Kinetic studies fitted well to the pseudo-second-order model, indicating chemisorption as the main mechanism. Thermodynamic analysis revealed that adsorption by SB-1 was spontaneous, irreversible, and endothermic, whereas SB-2 adsorption was spontaneous, reversible, and exothermic.
Adsorptive Interactions of Organic Compounds with Metal Ions
Organic Compounds for Sustainable Metal Adsorption Applications
Human Health Hazards of Fluoride Ions: A Case Study of Al-Busif Village Water Supply Station, Iraq
The current study aimed to assess the health risks of fluoride in drinking water from the Al-Busif Water Supply Station and the residential neighborhoods covered by its distribution pipeline network in the region of northern Iraq. One hundred water samples were collected from ten sites, including intake water, post-treatment water, and other sites distributed throughout residential neighborhoods. The study results indicated that fluoride ion concentrations were within the calculated safe limits for the city of Mosul, ranging between 0.173 ± 0.029 mgL-1 and 0.206 ± 0.05 mgL-1. As for the results of the pollution indices Pollution Index (PI), Fluoride Pollution Index (FPI), and Human Health Risk (HHR), the average values of the PI ranged between 0.249 ± 0.016 and 0.292 ± 0.041, classifying the water as no pollution. The same applies to the results of the FPI, which ranged between 1.88 and 1.90 , classifying the water as low pollution water. As for the potential HHR of fluoride, the Hazard quotient (HQi) values were within safe limits (less than 1.0), as the highest risk Hazard quotient values were among male children (0.251) and female children (0.258). The study also found higher hazard quotient (HQi) values among breastfeeding women compared to adult females, reaching values of 0.180. The study recommended periodic monitoring of water quality and the development of efficient scientific programs to reduce the risks of probabilistic pollution in the future.
Health risks of fluoride (HHR); Pollution index (PI); Fluoride pollution index of drinking water (F.PI); Water quality; Environmental pollution
Environmental Sciences Analytical Chemistry Hydrochemistry Public Health
Organic Residue Analysis of Late Bronze Age Ceramics from Aşağıseyit Höyük by GC-MS, a Key Settlement in Western Anatolia
In the present study, gas chromatography–mass spectrometry (GC–MS) was used to investigate organic residues (ORs) preserved in the sherds recovered from the Late Bronze Age layers of Aşağıseyit Höyük, one of the important ancient settlements of Western Anatolia, in order to identify the types of food processed in these vessels. According to the results, 8 out of the 50 sherds analyzed gave interpretable results according to their OR compositions. The sherds of E-18, E-24, E-30, and E-36 may have been used in processes involving the carcass meat of a ruminant animal. The sherds of E-38, E-39, and E-41 may also contain a ruminant animal or a dairy product. The ORs obtained from E-38 and E-39 of these sherds also indicate plant oils. These results show that the relevant vessels may have been used for cooking or storing animal products together with plant oils. It can be said that the OR in sample E-43 is predominantly a residue of plant oil and that this vessel may have been used mostly for materials containing plant oils.
Production and Characterization of Polyhydroxyalkanoates from Food Waste Using Indigenous Bacterial Strains
The accumulation of petrochemical plastics necessitates sustainable alternatives. This study investigated the production of polyhydroxyalkanoates (PHAs) using indigenous bacterial strains isolated from Balochistan's soils and five locally sourced food wastes: rice bran, potato peels, fruit pulp, dairy waste, and corn starch. The isolates were identified as Bacillus megaterium and Cupriavidusnecator via 16S rRNA sequencing. Fermentation parameters were systematically optimized for each strain. C. necator achieved a maximum PHA yield of 4.5 ± 0.3 g/L, constituting 85% of the cell dry weight, using Rice Bran at 30°C, pH 7.0, and 1% NaCl. Hydrothermal pretreatment increased yields by up to 36%, and nitrogen limitation enhanced polymer accumulation by 40-50%. Characterization by FTIR, NMR, and GC confirmed the synthesis of poly(3-hydroxybutyrate) (PHB) by B. megaterium and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) with up to 33% hydroxyvalerate by C. necator. The PHBV copolymer exhibited a tensile strength of 32-40 MPa and a degradation temperature of 248-268°C, properties comparable to polypropylene. These results demonstrate that indigenous Balochistan strains efficiently convert regional food wastes into bioplastics with competitive material properties, establishing viable substrate-specific and strain-dependent bioprocessing strategy.
Phytochemical Profiling, Antioxidant, Antibacterial, andWound Healing Effects of Rosemary Oil Hydrogel
Rosmarinus officinalis L., a Mediterranean perennial herb, is well known for its antibacterial, antioxidant, anti-inflammatory, and wound-healing properties. This study investigates the phytochemical profile of R. officinalis, including glycosides, terpenoids, phenols, flavonoids, saponins, alkaloids, and tannins, along with its biological activities. Quantitative analysis revealed high levels of terpenoids (71.15 ± 0.18 mg/mL), tannins (26.32 ± 0.16 mg TTA/mL), phenolics (8.20 ± 0.001 mg GAE/mL), and flavonoids (0.1874 ± 0.002 mg QE/mL). Gas chromatography– mass spectrometry (GC-MS) identified a chemotype with low 1,8-cineole (1.77%) and a highconcentration of 1,2-hexanediol (67.34%), which may enhance the formulation’s stability and suitability for medicinal and cosmetic applications due to its antimicrobial and humectant properties. The DPPH assay demonstrated strong antioxidant activity with an IC₅₀ value of 21.80 ± 0.56 μg/mL, which is more potent than ascorbic acid (IC₅₀ = 33.79 ± 0.33 μg/mL). Antimicrobial testing using the disc diffusion method showed moderate activity against Staphylococcus aureus (17.33 ± 0.45 mm at 50% concentration) and limited activity against Escherichia coli (12 mm at 50%) compared to gentamicin (24.3 mm and 23.1 mm, respectively). The rosemary oil hydrogel demonstrated a statistically significant improvement in wound contraction (66.87% ± 2.15% by Day 16, p< 0.05) in a Staphylococcus aureus-infected mouse model when compared to negative, placebo, and standard treatment groups. These results support the therapeutic potential of R. officinalis oil hydrogel for topical wound care, combining antimicrobial, antioxidant, and healing effects in a biocompatible formulation.
Rosemary oil, Phytochemical analysis, Total phenolic content, Total flavonoid content, Total tannin content, Antioxidant properties, Antibacterial activity, GC-MS, Animal studies.
Characterization and Modeling of Indoor PM2.5-Bound Benzo[a]Pyrene Concentration in Public Schools: A Comparative Study of Oredo and Uhunmonde Local Government Areas, Edo State, Nigeria
Indoor air quality (IAQ) has emerged as a critical concern for student health and well-being, as PM2.5 can transport toxic compounds like benzo[a]pyrene (B[a]P), posing significant health risks to vulnerable populations such as school children. This study compares indoor air quality in public schools between Oredo (urban LGA) and Uhunmwonde (rural LGA) in Edo State, Nigeria. Fortyeight PM2.5 samples were collected from eight sampling sites with meteorological parameters over one year. PM2.5 mass concentrations were determined gravimetrically, and samples were analyzed for PAH compounds using gas chromatography with Mass Spectroscopy (GC-MS). Data underwent multivariate analysis to determine source contributions and develop a predictive model for B[a]P concentrations using PM2.5 and meteorological parameters. Oredo classrooms exhibited substantially higher PM2.5 levels (45.3–63.7 μg/m³) than Uhunmwonde (21.7–30.8 μg/m³). Similarly, total PM2.5-bound PAH concentrations were higher in Oredo (1.27–1.47 μg/m³) than Uhunmwonde (1.14–1.19 μg/m³). High-molecular-weight (5–6-ring) PAHs dominated profiles at both locations, with Oredo showing a slightly greater proportion (3.06%) of these heavy PAHs. Principal component analysis (PCA) and diagnostic ratios indicated vehicular combustion (gasoline and diesel traffic) as the primary PAH source at both locations, with minor biomass or petroleum evaporation contributions. Estimated incremental lifetime cancer risks (ILCR) from PM2.5-bound PAHs were higher in Oredo than Uhunmwonde (adult ILCR: 1.3×10⁻⁵ vs. 9.5×10⁻⁶ for 24h exposure). Predictive models using PM2.5 and weather parameters achieved 91–96% accuracy, with robust regression providing the best fit. These findings highlight clear spatial differences, with Oredo schools facing substantially higher indoor PM2.5 and PAH contamination than Uhunmwonde schools.
PM2.5-bound PAHs, concentrations, model indoor, LGAs
Synthesis and Characterization of polypyrrole / Silver Nanoparticles Composites as Creatinine Sensor
The Jaffe reaction is commonly employed to detect creatinine. This work involves the creation of several electrochemical sensors for the detection of creatinine, utilizing films made from polymer composites with nanoparticles and picric acid. Based on the interaction mechanism of creatinine, we synthesized four working electrodes (WEs): polypyrrole (Ppy) alone, Ppy with silver nanoparticles (AgNPs), Ppy with picric acid, and a combination of Ppy, picric acid, and AgNPs. All these electrochemical sensors exhibited distinctive sensitivities for creatinine detection. The performance and electrochemical behavior of the sensors were evaluated using cyclic voltammetry. AgNPs were synthesized biologically using Capsicum annuum leaves extract, serving as both a reducing and capping agent. Ppy was prepared via chemical polymerization using ammonium persulfate (APS) as an oxidizing agent in the presence of hydrochloric acid as a dopant. The sensor presented a limit of detection (LOD) of 0.144 mg/dL and a limit of quantification (LOQ) of 0.44 mg/dL. Ppy and AgNPs were characterized by UV-Visible spectroscopy, field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), and X-ray diffraction (XRD). The prepared sensors were successfully applied for the direct detection of creatinine.
creatinine, biosensor, silver nanoparticles, picric acid, polypyrrole
academic study for bio detection of creatinine by synthesis nano composites films
Comparative Study of Mass Transfer Limitation Steps in Bemacid Yellow and Methyl Red Biosorption: Investigation using Unique and Binary Resistance Models
In this study, brewery waste was employed as an adsorbent to remove two dyes: Bemacid Yellow (BY) and Methyl Red (MR). Optimal operational conditions were determined using the Bach mode. Kinetic data fitting was carried out using pseudo first and second order models. The results revealed that the pseudo second order model exhibited a better fit for both dyes, with a high determination coefficient (R2=0.99). The single resistance model demonstrated a positive correlation between the initial dye concentration (C0) and the external mass coefficient (kf) described by the empirical relationships: kfMR = 0.00044C0.650 and kf(by) = 0.0208C0.0330 for MR and BY dyes adsorption, respectively. According to the obtained results from the binary resistances diffusion model, it was determined that pore diffusion played a dominant role in the adsorption process of both dyes. This conclusion was supported by the observed increase in the film diffusion coefficient (Df) values. On the other hand, alternative formulas indicate that the adsorption processes of BY were primarily controlled by film diffusion. To summarize, the adsorption process of both dyes is influenced by two key steps: pore diffusion and film diffusion. This analysis provides insights into the significance of each parameter and their respective contributions to the overall adsorption mechanism.
Bemacid Yellow, Methyl Red, Kinetic models, Mass transfer, Binary resistance
Transforming Transformer Oil Waste: A Hybrid Biological–Oxidative Strategy for PCB Decontamination
Polychlorinated biphenyls (PCBs) are dangerous and long-lasting chemicals that bioaccumulate in the food chain. The use of PCBs in transformer oil as heat-resistant compounds is widespread and has received more attention in recent years. This work used a sequential degradation methodology that combined an advanced oxidation mechanism with anaerobic biological treatment, indicating that these methods improved degradation efficiency and resulted in 100% PCB removal from industrial effluent containing transformer oils. Three alternative combinations were used: upflow anaerobic sludge blanket reactor (UASB) for 6 h followed by micro-bubble ozonation for 1 h, UASB for 6 h followed by the Fenton process for 1 h, and ozonation for 1 h followed by the Fenton process. Integrated approaches were shown to significantly reduce PCBs, with levels below detection in both the UASB and ozonation combinations, as well as the ozonation and Fenton combination. The Fenton method and upflow anaerobic sludge blanket reactor (UASB) reduced 2,4,5-trichlorobiphenyl to 0.3 and 2.4 µg/mL, respectively. The treatments significantly reduced chemical oxygen demand (COD). The UASB-ozonation combination reduced COD concentration from 785 mg/L to 364 mg/L, the UASB-Fenton combination reduced it to 407 mg/L, and the ozonation-Fenton combination achieved the greatest reduction, reaching 260 mg/L. The study demonstrated the degradation of 2,4,5-trichlorobiphenyl and 2,3,4-trichlorobiphenyl. The initial concentration of PCBs in wastewater was 24.4 µg/mL for 2,4,5-trichlorobiphenyl and 12.1 µg/mL for 2,3,4-trichlorobiphenyl. However, after treatment, the value went below the detection limit due to an integrated treatment method. In the UASB-Fenton combination, the concentrations of 2,4,5-trichlorobiphenyl and 2,3,4-trichlorobiphenyl were reduced to 2.4 and 0.3 µg/mL, respectively.
Environmental chemistry; Environmental Toxicology; Wastewater treatment;Transformer oil; PCBs; Sequential degradation
Efficient Concurrent Analysis of Mesotrione, Atrazine, Benoxacor and S-Metolachlor in Herbicide Formulate: Developing and Validating a Reversed-Phased HPLC Method
An effective, simple and reliable simultaneous determination method for four active compounds, mesotrione, benoxacor, atrazine and S- metolachlor, in herbicide formulate was first-time developed and substantiated in current study using reversed-phased high performance liquid chromatography, following ICH guidelines. The chromatographic separation with fine resolution was conducted on a 5 μm C-18 column (L x id, 15 cm x 4.6 mm) using acetonitrile:water 70:30 (v/v) at 1.0 mL/min flow rate and wavelength 260 nm (UV detector). The retention times for mesotrione, atrazine, benoxacor and S-metolachlor were obtained as 1.90, 3.50, 3.95, and 5.10 min, respectively. Limits of detection of mesotrione, atrazine, benoxacor and S-metolachlor were found to be 2.57, 2.27, 1.28, and 1.32 μg/mL, whereas limits of quantitation were 7.80, 6.86, 3.86, and 4.01 μg/mL, respectively. The regression coefficients from calibration curves were ˃ 0.998 for all studied pesticides. The method reproducibility was evaluated as intra-day precision (0.85–1.52%RSD) and inter-day precision (0.67–1.81 %RSD). The method accuracy was estimated through inter-laboratory comparison among three laboratories. The developed method is quite rapid, inexpensive, robust, precise, accurate, linear and sensitive for the purpose of quality control check of mesotrione, atrazine, benoxacor and S-metolachlor simultaneously in herbicide formulations.
Crop protection agents, Liquid chromatography, Method optimization, Robustness, UV detector, System suitability
Municipal Solid Waste (Newspaper) — A Lignocellulosic Feedstock Conversion to Biofuel: A Prospective Solution to Energy and Waste Management Problem
Bioethanol, an alcohol-based fuel is produced from biowaste. The current research focuses on utilizing newspaper waste as a substrate for bioethanol production. The waste newspaper was pretreated and subjected to two important bioethanol production steps: (1) saccharification and (2) fermentation. Aspergillus niger utilized for the saccharification hydrolyzed the newspaper substrate by converting the complex compounds into simpler compounds, where lactose and chemically defined media enhanced the cellulolytic activity. The simpler sugars produced were fermented using the Saccharomyces cerevisiae and converted to bioethanol. The bioethanol samples were subject to different analyses, including dichromate oxidation tests, UV-Vis Spectroscopy, and High-Performance Liquid Chromatography (HPLC). The dichromate oxidation test confirmed the presence of bioethanol as the color of the samples changed from yellowish orange to green. The UV-Vis spectroscopy indicated the maximum bioethanol yield of 3.814% v/v (variant sample 1-lactose) and 5.049% v/v (variant sample 2-chemically defined media) on the 6th day of fermentation. HPLC further confirmed the bioethanol production as the peaks of bioethanol at retention times of 2.130 min (variant sample 1-lactose) and 2.112 min (variant sample 2-chemically defined media) matched the peak of standard ethanol at the retention time of 1.935 min. The present research concludes that newspaper waste is the potential substrate for bioethanol production.
Bioethanol, Newspaper, Waste management, Lignocellulose
Adsorption Studies of Cyanide (CN) - on Alumina
In this investigation, adsorption of cyanide on to alumina has been studied by means of batchtechnique. Percentage adsorption was determined for Alumina-Cyanide solution system as a function of (i) contact time, (ii) pH, (iii) adsorbate concentration and (iv) temperature. Adsorption data has been interpreted in terms of Freundlich and Langmuir equations. Thermodynamics parameters for the adsorption system have been determined at three different temperatures. The value of ΔHo=5.448kJ/mole and ΔGo=-7.162kJ/mole at 283K suggest that the adsorption of cyanide on Alumina is an endothermic and spontaneous process.
An Analytical Implication to Chlorides Determinationin Catalytic Hydrodechlorination Reaction of DDTby Ion Chromatography
Chemical degradation of Organochlorine pesticide (OCPs) in hydrodechlorination reactions were first systematically investigated using dichloro diphenyl trichloroethane (DDT) as the model pesticide. The reaction of DDT produced an equimolar amount of HCl and DDE resulting from initial attack and was identified using GC-ECD. The produced DDE was dechlorinated by using Fe/Ni catalysts with a solution of NaOH in 2-propanol/methanol (99:1 v/v) at temperature below 82 oC. The developed method efficiently converted DDT in the range of 3.5 – 3500 mg/l to chlorine-free product within 240 minutes. Chloride ions concentrations were also identified as a product using Ion Chromatography.
Chloride, Hydrodechlorination, DDT, Organochlorine pesticides
Evaluation of the Iodine Concentration in Serumand Urine of Hypothyroid Males Using anInexpensive and Rapid Method
The aim of present study was to evaluate the iodine/iodide status in biological samples (serum and urine) of 172 male hypothyroid patients (HPs) and their supplemental effects on thyroid hormones. For comparison purpose, non-goitrous subjects (n= 220) of same age group and socioeconomic status were also studied. A simple and rapid iodide-ion selective electrode (ISE) was used to measure the concentration of iodine in microwave assisted acid digested serum and urine samples. Quality control for the methodology was established with certified samples and with those obtained by conventional wet acid digestion method on the same certified reference materials (CRMs) and real samples. A linear calibration curve was obtained for a reasonable concentration range of the potassium iodide solutions. The mean concentration of iodine in the serum and urine samples of the HPs was significantly reduced as compared to control male subjects (p< 0.01). The low levels of free triiodothyronine and thyroxin were found in HPs than age matched healthy control (p< 0.005 and 0.002) respectively while high levels of thyroid stimulating hormone were observed in HPs (p< 0.008). The proposed method was relatively efficient as well as cost effective by using inexpensive equipment. It was observed that iodine in biological samples of HPs can play an important role in determining the severity of the hypothyroidism.
Iodine, male, hypothyroid, ion selective electrode, supplements
Effects of Chicken Frying on Soybean, Sunflower and Canola Oils
Consequences of discontinuous chicken frying on some important parameters of soybean (SBO), sunflower (SFO) and canola oil (CLO) at constant temperature (190 0C) for 12h were examined. The quality parameters such as fatty acid composition (FAC) with special emphasis on trans fatty acids (TFA’s), free fatty acids (FFA’s), iodine value (IV) and peroxide value (PV) of soybean, sunflower and canola oils were evaluated by taking out the oil samples from the fryer at an interval of 2 h. The total trans fatty acids increased during frying of chicken in the range of (0.77- 1.67, 1.02- 2.62 and 1.29-3.14 %) in SFO, SBO and CLO. Other chemical parameters such as free fatty acids (0.03-0.78, 0.05-0.49 and 0.19- 1.47 %), peroxide value (1.51-3.04, 2.11-6.07 and 2.90- 8.02 meq/kg) increased where as iodine value (154.21-140.69, 134.50 and 116.10-99.70 g/100g) was decreased with respect to time of frying in SFO, SBO and CLO, respectively.
chicken meat, frying, chemical parameters, fatty acid composition
Simpler and Faster Spectrophotometric Determination of Diclofenac Sodium in Tablets, Serum and Urine Samples
This work describes a simple, sensitive, rapid and economical analytical procedure for direct spectrophotometric evaluation of diclofenac sodium (DS) using aqueous medium without using a chemical reagent. Parameters like time, temperature, acidic and basic conditions and interference by analgesic drugs were studied for a 5μg ml-1 solution of DS at 276 nm. Under optimized parameters, a linear working range of 0.1–30 g ml-1 with regression coefficient of 0.9998 and lower detection limit of 0.01 g ml-1 was obtained. The method was applied for DS contents in tablets, serum and urine samples.
Diclofenac sodium; UV-Visible spectrophotometer; tablets; serum; urine
Determination of Toxic Metals in Different Brand of Chocolates and Candies, Marketed in Pakistan
In present study three toxic metals, cadmium (Cd), nickel (Ni) and lead (Pb) were determined in chocolates and candy samples available in local markets of Hyderabad, Pakistan. Concentrations of understudy toxic metals (TMs) were determined by electrothermal atomic absorption spectrometry (ETAAS) prior to microwave assisted acid digestion. Validation of the methodology was performed by standard addition method and conventional acid digestion on electric hot plate to obtained TMs concentration, for comparative purpose to obtain results within the 95% confidence level. No significant differences were observed for TMs obtained from both methods (P = 0.05). The concentration of Cd, Ni and Pb were observed in chocolates and candy samples is ranged as of 0.099 - 0.353, 1.45 - 4.33 and 1.11 - 2.48 μg/g, respectively. The results indicated that cocoa-based chocolates have higher contents of TMs than milk- based chocolates and candies.
Toxic metals, Chocolates, Candies, Atomic absorption spectrometry
Limnological Studies of Keenjhar Lake, District,Thatta, Sindh, Pakistan
Limnological studies of Keenjhar Lake were carried out during January 2003 to December 2005. The present study deals with physico - chemical parameters such as, temperature, pH, alkalinity, chlorides, conductivity, total dissolve solids, turbidity, dissolve oxygen, calcium and magnesium. The maximum and minimum range of physico - chemical properties were as, temperature 18 - 33 ⁰C from station 2 in January and August respectively, pH 7.3 - 8.9 in September and June respectively, alkalinity 160 - 240 mg L-1 in July and January respectively, minimum chlorides 30 mg L-1 in September and maximum 85 mg L-1 in December, conductivity 320 S cm-1 in September and 496 S cm-1 in December, total dissolve solids were 240 mg L-1 in September and 391 mg L-1 in October, turbidity was 30 NTU in December and 78 NTU in May, dissolve oxygen was 7.0 mg L-1 in January and 9.0 mg L-1 in July, calcium 50 mg L-1 in July and September and 78 mg L-1 in October, magnesium 21 mg L-1 in August and September, 35 mg L-1 June, and it is concluded that the variation in parameters were due to rain and flow of River Indus.
Physico - chemical properties, Keenjhar Lake, Thatta
Effect of Various Parameters on the Dispersionof Ultra Fine Iron Ore Slurry. Part-1
The effect of various dispersion parameters; such as slurry pH, solid concentration, stirring speed and time, and water quality has been extensively studied for stabilization the ultra fine iron ore slurry prior to selective flocculation. The PZC of Dilband iron ore system was found by using the Zetaphormeter III (CAD E400) at pH value of 4.25. The set of dispersion parameters was optimized on the basis of weight percent and the percent entrapment of fine particles (10μm) sedimented in 2.5min settling time. Finally the selectivity of the optimal dispersion parameters was evaluated on the basis of elemental analysis of the sediment. The optimal conditions for 38μm ultra fine iron ore slurry in double distilled water were found at concentration of 7.5%solid, pH10.5, stirring speed 2000rpm, and stirring time 5min.
Dilband iron ore, dispersion, zeta potential, polyvalent cations