Application of a permethrin immunosorbent assay method to residential soil and dust samples

Abstract

A low-cost, high throughput bioanalytical screening method was developed for monitoring cis/trans-permethrin in dust and soil samples. The method consisted of a simple sample preparation procedure [sonication with dichloromethane followed by a solvent exchange into methanol:water (1:1)] with bioanalytical detection using a magnetic particle enzyme-linked immunosorbent assay (ELISA). Quantitative recoveries (83–126 %) of cis/trans-permethrin were obtained for spiked soil and dust samples. The percent difference of duplicate ELISA analyses was within ± 20 % for standards and ± 35 % for samples. Similar sample preparation procedures were used for the conventional gas chromatography/mass spectrometry (GC/MS) analysis except that additional cleanup steps were required. Recoveries of cis/trans-permethrin ranged from 81 to 108 % for spiked soil and dust samples by GC/MS. The ELISA-derived permethrin concentrations were highly correlated with the GC/MS-derived sum of cis/trans-permethrin concentrations with a correlation coefficient (r) of 0.986. The ELISA method provided a rapid qualitative screen for cis/trans-permethrin in soil and dust while providing a higher sample throughput with a lower cost as compared to the GC/MS method. The ELISA can be applied as a complementary, low-cost screening tool to prioritize and rank samples prior to instrumental analysis for exposure studies.

Keywords:

• Human exposure
• cis-permethrin
• trans-permethrin
• immunoassay
• ELISA
• soil
• dust

Acknowledgments

The United States Environmental Protection Agency funded the research described here under Contract # 68D99-011 and STAR Grant R829363 to Battelle. It has been subjected to Agency review and approved for publication. Mention of trade names and commercial products does not constitute endorsement or recommendation for use.

Notes

^a Recovery, % = (measured permethrin in the spiked sample - measured permethrin in the nonspiked sample)/spike level*100.

^b Two levels were used for the spiked soil samples (N = 6): (1) 5 ng g⁻¹ each of cis/trans-permethrin, and (2) 10 ng g⁻¹ each of cis/trans-permethrin. Reported recovery data were the average ± standard deviation of all the spiked soil samples.

^c Spike level was 400 ng g⁻¹ for the dust sample (N = 6).

^d Recovery data for cis-permethrin.

^e Recovery data for trans-permethrin.

^a The estimated detection limit was 0.5 ng g⁻¹; one half of the estimated detection limit was used for non-detects.

^b The estimated detection limit was 4 ng g⁻¹; one half of the estimated detection limit was used for non-detects.