Determination of Deltamethrin and Its Metabolites, 3‐Phenoxybenzoic Acid and 3‐Phenoxybenzyl Alcohol, in Maternal Plasma, Amniotic Fluid, and Placental and Fetal Tissues by HPLC

Abstract

Pyrethroid insecticide deltamethrin [(S)‐α‐cyano‐3‐phenoxybenzyl‐(1R,3R)‐3‐(2,2‐dibromovinyl)‐2,2‐dimethylcyclo‐propane‐1‐carboxylate] is widely used throughout the world on cotton, crops, and stored products. It is also used to treat livestock and is, thus, a public health concern. The toxic effects of deltamethrin in mammals include tremors and salivation. Few studies have been performed to characterize the toxicokinetics of deltamethrin, mainly due to the lack of a sensitive and reliable analytical method. An analytical method was, thus, developed and validated for the determination of deltamethrin concentrations in pregnant rat maternal plasma, amniotic fluid, placenta, and fetus using protein precipitation and reversed‐phase high performance liquid chromatography. The limits of quantitation for deltamethrin were 100 ng/mL for amniotic fluid and 200 ng/mL for plasma, placental and fetal tissues. Recoveries ranged from 83.0% to 98.1% for deltamethrin, 90.5% to 99.7% for 3‐phenoxybenzoic acid (3‐PB Acid), and 82.4% to 92.3% for 3‐phenoxybenzyl alcohol (3‐PB Alc). The intra‐day (n = 5) precision and accuracy for deltamethrin were in the range of 0.2–7.8 (relative standard deviation, RSD) and 0.4–11.2% (% error). The intra‐day (n = 5) precision and accuracy for 3‐PB Acid were in the range of 1.1–13.6% and 1.1–13.0%. The intra‐day (n = 5) precision and accuracy for 3‐PB Alc were in the range of 0.6–11.5% and 1.9–13.7%. Inter‐day (n = 15) precision and accuracy for deltamethrin ranged from 3.1% to 12.0% (% RSD) and 2.5% to 8.8% (% error). Inter‐day (n = 15) precision and accuracy for 3‐PB Acid ranged from 1.8% to 12.5% and 2.1% to 10.0%. Inter‐day (n = 15) precision and accuracy for 3‐PB Alc ranged from 2.4% to 11.3% and 3.1% to 10.5%.

Keywords:

• Deltamethrin
• HPLC
• Toxicokinetics
• Pregnant rat

Acknowledgments

The authors wish to thank the University of Georgia Research Foundation and the US Environmental Protection Agency Grant #R830800‐01 for support of this work.