A single method for detecting 11 organophosphate pesticides in human plasma and breastmilk using GC-FPD

Abstract

Organophosphate (OP) pesticides are widely used for crop protection in many countries including Thailand. Aside from causing environmental contamination, they affect human health especially by over-stimulating of the neurotransmission system. OP pesticides, as with other non-persistent pesticides, degrade quickly in the environment as well as are metabolized quite rapidly in humans. Assessing human exposures to these compounds requires analytical methods that are sensitive, robust, and most importantly, suitable for specific laboratory settings. The aim of this study was to develop and validate an analytical method for measuring 11 OP pesticide residues in human plasma and breast milk. Analytes in both plasma and breast milk samples were extracted with acetone and methylene chloride, cleaned-up using aminopropyl solid phase extraction cartridges, and analyzed by gas chromatography with flame photometric detection. The optimized method exhibited good linearity, with the coefficients of determination of 0.996–0.999 and <7% error about the slope. Extraction recoveries from spiked plasma and breast milk samples at low and medium concentrations (0.8–5.0 and 1.6–10 ng mL−1, respectively) ranged from 59.4 % (ethion) to 94.0 % (chlorpyrifos). Intra-batch and inter-batch precisions ranged from 2.3–18.9% and 5.8–19.5%, respectively. Method detection limits of plasma and breast milk ranged from 0.18–1.36 and 0.09–2.66 ng mL−1, respectively. We analyzed 63 plasma and 30 breastmilk samples collected from farmworkers in Chiang Mai Province to determine the suitability of this method for occupational exposure assessment. Of the 11 pesticides measured, seven were detected in plasma samples and five were detected in breast milk samples. Mass spectrometry was used to confirm results. Overall, this method is rapid and reliable. It offers the laboratories with limited access to mass spectrometry a capacity to investigate levels OP pesticides in plasma and breastmilk in those occupationally exposed for health risk assessment.

Sex-Specific Neurotoxic Effects of Organophosphate Pesticides Across the Life Course

“…Most animal studies in the literature administer the OP for a brief dosing regimen (4–10 days duration); however, humans are likely exposed not only during gestation but chronically, throughout weaning and childhood as well, as OPs have been detected in breast milk [96] and measured in children. One experimental study assessed the effects of a more chronic dosing schedule (PND1-21) of either CPF or methyl parathion and found that both OPs impacted working memory of males while females remained unaffected [68].…”

Progress of the discovery, application, and control technologies of chemical pesticides in China

“…The flame photometric detector (FPD) is a highly sensitive and highly selective detector that responds only to the phosphorus-containing compounds. FPDs have been widely used in the environmental protection and to monitor pesticide residues in food (Patel et al 2004;Chen et al 2016;Du et al 2016;Naksen et al 2016;Xiao et al 2016). However, gas chromatography cannot be used for compounds with high boiling points, nonvolatile substances, and thermally unstable compounds.…”

Solidification of floating organic droplet microextraction for determination of seven insecticides in fruit juice, vegetables and agricultural runoff using gas chromatography with flame ionization and mass spectrometry detection

“…To improve the agricultural yield and product quality, insecticides are widely used for controlling and eliminating pests such as rats and insects . Organophosphates (OPP) and pyrethroids (PYR) are among the most widely used insecticides in Thailand . Although insecticides are effective in their acute toxicity poses risks to human health , and bioaccumulation is detrimental to the environment .…”