Development of Gas Chromatographic Method with Electron Capture Detector for Determination of Some PCDDs in Wheat and Rice Grain Matrix

  • Iffat Abdul Tawab Khan Department of Chemistry, Federal Urdu University of Arts, Science and Technology, Gulshan-e-Iqbal Campus, Karachi-75300, Pakistan
  • Qurrat ul Ain Department of Chemistry, University of Karachi
  • Zahida Tasneem Maqsood Department of Chemistry, University of Karachi, Karachi-75270, Pakistan

Abstract

This study develops a gas chromatographic method coupled to micro-electron capture detector to determine four basic polychlorinated dibenzo-p-dioxins (PCDDs) congeners: 1, 1,2,3,7,8-pentachlorodibenzo-p-dioxin; 2, 2,3,7,8-tetrachlorodibenzo-p-dioxin; 3, 1,2,3,6,7,8-hexachloro-dibenzo-p-dioxin; and 4, 1,2,3,4,6,7,8-heptachlorodibenzo-p-dioxin  in wheat and rice. The PCDDs were extracted using 1:1 acetone:n-hexane mixture followed by cleaning with acidic aluminium oxide in polypropylene mini columns and eluted with dichloromethane. In quantitative determinations, the limit of detection for congener 1 of PCDDs was 0.4 ng mL-1 while for other congeners (2–4) it was found to be 1.0 ng mL-1. The congener 1 was checked at spiking levels of 0.02, 0.05 and 0.1 ng g-1, and its recovery was 85.96–120.74% and 95.32–116.88% from wheat and rice, respectively. Wheat and rice were also spiked by congers 2–4 at spiking levels of 0.05, 0.1 and 0.5 ng g-1; the recovery ranges from wheat were 87.70–115.54%, 85.64–117.88% and 88.40–119.32% for congener 2, 3 and 4, respectively, while from rice the recovery was 77.67–115.68%, 83.18–119.68% and 79.76–131.15% for congener 2, 3 and 4, respectively. The limit of quantification was determined as 0.1 ng g-1 for congener 1 and 0.5 ng g-1 for other three PCDDs (2–4). The intra-day and inter-day RSDs of peak areas (n = 3) for four congeners (2 ng mL-1) were ranged at 2.5–8.1% and 3.1–10.6%, respectively. This study provides a simple and cost-effective gas chromatographic-electron capture detector method to study some basic PCDDs in wheat and rice grains first time in Pakistan with fair precision and accuracy when expensive high resolution gas chromatographic-mass spectrometry method is not accessible.

Published
Jun 19, 2019
How to Cite
KHAN, Iffat Abdul Tawab; AIN, Qurrat ul; MAQSOOD, Zahida Tasneem. Development of Gas Chromatographic Method with Electron Capture Detector for Determination of Some PCDDs in Wheat and Rice Grain Matrix. Pakistan Journal of Analytical & Environmental Chemistry, [S.l.], v. 20, n. 1, p. 1-10, june 2019. ISSN 2221-5255. Available at: <http://pjaec.pk/index.php/pjaec/article/view/429>. Date accessed: 23 july 2019. doi: http://dx.doi.org/10.21743/pjaec/2019.06.01.