Determination of pesticide residues in urine by chromatography-mass spectrometry: methods and applications

Introduction

Pollution has emerged as a significant threat to humanity, necessitating a thorough evaluation of its impacts. As a result, various methods for human biomonitoring have been proposed as vital tools for assessing, managing, and mitigating exposure risks. Among these methods, urine stands out as the most commonly analyzed biological sample and the primary matrix for biomonitoring studies.

Objectives

This review concentrates on exploring the literature concerning residual pesticide determination in urine, utilizing liquid and gas chromatography coupled with mass spectrometry, and its practical applications.

Method

The examination focused on methods developed since 2010. Additionally, applications reported between 2015 and 2022 were thoroughly reviewed, utilizing Web of Science as a primary resource.

Synthesis

Recent advancements in chromatography-mass spectrometry technology have significantly enhanced the development of multi-residue methods. These determinations are now capable of simultaneously detecting numerous pesticide residues from various chemical and use classes. Furthermore, these methods encompass analytes from a variety of environmental contaminants, offering a comprehensive approach to biomonitoring. These methodologies have been employed across diverse perspectives, including toxicological studies, assessing pesticide exposure in the general population, occupational exposure among farmers, pest control workers, horticulturists, and florists, as well as investigating consequences during pregnancy and childhood, neurodevelopmental impacts, and reproductive disorders.

Future directions

Such strategies were essential in examining the health risks associated with exposure to complex mixtures, including pesticides and other relevant compounds, thereby painting a broader and more accurate picture of human exposure. Moreover, the implementation of integrated strategies, involving international research initiatives and biomonitoring programs, is crucial to optimize resource utilization, enhancing efficiency in health risk assessment.

Human Biomonitoring of Environmental and Occupational Exposures by GC-MS and Gas Sensor Systems: A Systematic Review

Environmental chemicals and contaminants coming from multiple external sources enter the human body, determining a potential risk for human health. Human biomonitoring (HBM), measuring the concentrations of biomarkers in human specimens, has become an emerging approach for assessing population-wide exposure to hazardous chemicals and health risk through large-scale studies in many countries. However, systematic mapping of HBM studies, including their characteristics, targeted hazardous pollutants, analytical techniques, and sample population (general population and occupationally exposed workers), has not been done so far. We conducted a systematic review of the literature related to airborne hazardous pollutants in biofluids to answer the following questions: Which main chemicals have been included in the literature, which bodily fluids have been used, and what are the main findings? Following PRISMA protocol, we summarized the publications published up to 4 February 2021 of studies based on two methods: gas-chromatography/mass spectrometry (GC/MS) and electronic noses (e-noses). We screened 2606 records and 117 publications were included in the analysis, the most based on GC/MS analysis. The selected HBM studies include measurements of biomarkers in different bodily fluids, such as blood, urine, breast milk, and human semen as well as exhaled air. The papers cover numerous airborne hazardous pollutants that we grouped in chemical classes; a lot of hazardous and noxious compounds, mainly persistent organic pollutants (POPs) and volatile organic compounds (VOCs), have been detected in biological fluids at alarming levels. The scenario that emerged from this survey demonstrates the importance of HBM in human exposure to hazardous pollutants and the need to use it as valid tool in health surveillance. This systematic review represents a starting point for researchers who focus on the world of pollutant biomonitoring in the human body and gives them important insights into how to improve the methods based on GC/MS. Moreover, it makes a first overview of the use of gas sensor array and e-noses in HBM studies.

Estimating household exposure to pyrethroids and the relative contribution of inhalation pathway in a sample of Japanese children

Several synthetic pyrethroids are suspected to have carcinogenicity or reproductive toxicity. However, there is little knowledge about indoor air pollution in residences or the extent of intake by the residents of the newly developed pyrethroids, transfluthrin, profluthrin, and metofluthrin, although they have been widely used indoors as mosquito repellents and mothproof repellents in recent years. In the present study, the household exposure to pyrethroids through all exposure pathways and the contribution of inhalation pathway in Japanese children were examined by measuring urinary pyrethroid metabolites in the children and the airborne pyrethroids in their residences. Urine excreted first after waking up was collected from subjects aged 6 to 15 years (n = 132), and airborne pyrethroids were sampled in the subjects' bedrooms for 24 h. Nineteen pyrethroids and their nine urinary metabolites were measured. Their daily intakes estimated were as follows (median, ng/kg b.w./d): bifenthrin, 56; transfluthrin, 22; metofluthrin, 11; profluthrin, 0.86. The contribution rates of the amounts absorbed by inhalation to the amounts absorbed via all of the exposure pathways while at home tended to decrease in the following order: profluthrin (median 15%) ≈ transfluthrin (14%) > metofluthrin (1%) > bifenthrin (0.1%). Transfluthrin was considered to be the most notable pyrethroid as an indoor air pollutant. Our study demonstrated widespread exposure to transfluthrin, metofluthrin, profluthrin, and bifenthrin in a sample of Japanese children.

Off-line microextraction by packed sorbent combined with on solid support derivatization and GC-MS: Application for the analysis of five pyrethroid metabolites in urine samples

A novel, fast and eco-friendly analytical method using microextraction by packed sorbent coupled to large volume injection-gas chromatography-mass spectrometry (MEPS-LVI-GC-MS) was developed for the determination of five pyrethroid metabolites (cis-2,2-dimethyl-3-(2-chloro-3,3,3-trifluoro-1-propenyl)-cyclopropanecarboxylic acid, cis/trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane-1-carboxylic acids, cis-(2,2-dibromovinyl)-2,2-dimethylcyclopropane-1-carboxylic acid and 3-phenoxybenzoic acid) in human urine. MEPS was performed off-line using a manually-operated semiautomatic syringe (eVol), and several parameters including the sample pH, extraction sorbent, washing solvent, volume and type of elution solvent and number of draw-eject cycles were optimized. Analytes were extracted from enzymatically hydrolyzed urine using a C18 solid phase with subsequent simultaneous derivatization and elution with a mixture of 1,1,1,3,3,3-hexafluoroisopropanol and diisopropylcarbodiimide in n-hexane (on-line derivatization). The optimized method was validated, with linearity established from 0.05 to 25ngmL^-1 and R values > 0.99. Obtained quantification limits were in the range of 0.06-0.08ngmL^-1, and the precision expressed as relative standard deviation (RSD) was below 14% for all of the analytes. The method was cross-validated with a reference approach based on liquid-liquid extraction-gas chromatography-mass spectrometry (LLE-GC-MS) by analyzing 21 urine samples.

Temporal variability of pyrethroid metabolite levels in bedtime, morning, and 24-h urine samples for 50 adults in North Carolina

Pyrethroid insecticides are widely used to control insects in both agricultural and residential settings worldwide. Few data are available on the temporal variability of pyrethroid metabolites in the urine of non-occupationally exposed adults. In this work, we describe the study design and sampling methodology for the Pilot Study to Estimate Human Exposures to Pyrethroids using an Exposure Reconstruction Approach (Ex-R study). Two major objectives were to quantify the concentrations of several pyrethroid metabolites in bedtime, first morning void (FMV), and 24-h urine samples as concentration (wet weight), specific-gravity (SG) corrected, creatinine (CR) corrected, and excretion rate values for 50 Ex-R adults over a six-week monitoring period and to determine if these correction approaches for urine dilution reduced the variability of the biomarker levels. The Ex-R study was conducted at the United States Environmental Protection Agency's Human Studies Facility in Chapel Hill, North Carolina USA and at participants' homes within a 40-mile radius of this facility. Recruitment of participants and field activities occurred between October 2009 and May 2011. Participants, ages 19-50 years old, provided daily food, activity, and pesticide-use diaries and collected their own urine samples (bedtime, FMV, and 24-h) during weeks 1, 2, and 6 of a six-week monitoring period. A total of 2503 urine samples were collected from the study participants. These samples were analyzed for the pyrethroid metabolites 3-phenoxybenzoic acid (3-PBA), cis/trans-3-(2,2-dichlorovinyl)-2,2-dimethyl-cyclopropane carboxylic acid (cis/trans-DCCA), and 2-methyl-3-phenylbenzoic acid (MPA) using high performance liquid chromatography/tandem mass spectrometry. Only 3-PBA was frequently detected (>50%) in the adult urine samples. Median urinary 3-PBA levels were 0.88 ng/mL, 0.96 ng/mL-SG, 1.04 ng/mg, and 1.04 ng/min for concentration, SG-corrected, CR-corrected, and excretion rate values, respectively, across all urine samples. The results showed that median urinary 3-PBA concentrations were consistently the lowest in FMV samples (0.77 ng/mL, 0.68 ng/mL-SG, 0.68 ng/mg, and 0.58 ng/min) and the highest in 24-h samples (0.92 ng/mL, 1.06 ng/mL-SG, 1.18 ng/mg, and 1.19 ng/min) across all four methods. Intraclass correlation coefficient (ICC) estimates for 3-PBA indicated poor reproducibility (<0.22) for all urine sample types and methods over a day, week, and six weeks. Correcting for urine sample dilution, based on either SG, CR or urine output, introduced additional measurement variability both between- and within-individuals. These results indicate that a single measure of urinary 3-PBA was not sufficient to characterize average exposure regardless of sample type, correction method, and time frame of collection. In addition, the study results can be used to inform the design of exposure characterization strategies in relevant environmental epidemiology studies in the future.

Endocrine disruptor activity of multiple environmental food chain contaminants

Industrial chemicals, antimicrobials, drugs and personal care products have been reported as global pollutants which enter the food chain. Some of them have also been classified as endocrine disruptors based on results of various studies employing a number of in vitro/vivo tests. The present study employed a mammalian reporter gene assay to assess the effects of known and emerging contaminants on estrogen nuclear receptor transactivation. Out of fifty-nine compounds assessed, estrogen receptor agonistic activity was observed for parabens( n = 3), UV filters (n = 6), phthalates (n = 4) and a metabolite, pyrethroids (n = 9) and their metabolites (n = 3). Two compounds were estrogen receptor antagonists while some of the agonists enhanced 17b-estradiol mediated response.This study reports five new compounds (pyrethroids and their metabolites) possessing estrogen agonist activity and highlights for the first time that pyrethroid metabolites are of particular concern showing much greater estrogenic activity than their parent compounds.