Qualitative Profiling and Quantification of Neonicotinoid Metabolites in Human Urine by Liquid Chromatography Coupled with Mass Spectrometry

Abstract

Neonicotinoid pesticides have been widely applied for the production of fruits and vegetables, and occasionally detected in conventionally grown produce. Thus oral exposure to neonicotinoid pesticides may exist in the general population; however, neonicotinoid metabolites in human body fluids have not been investigated comprehensively. The purpose of this study is the qualitative profiling and quantitative analysis of neonicotinoid metabolites in the human spot urine by liquid chromatography coupled with mass spectrometry (LC/MS). Human urine samples were collected from three patients suspected of subacute exposure to neonicotinoid pesticides. A qualitative profiling of urinary metabolites was performed using liquid chromatography/time-of-flight mass spectrometry (LC/TOFMS) with a database of nominal molecular weights of 57 known metabolites of three neonicotinoid pesticides (acetamiprid, Imidacloprid, and clothianidin), as well as the parent compounds. Then a quantitative analysis of selected urinary metabolites was performed using liquid chromatography/tandem mass spectrometry (LC/MS/MS) with a standard pesticide and metabolite, which were detected by the qualitative profiling. The result of qualitative profiling showed that seven metabolites, i.e. an acetamiprid metabolite, N-desmethyl-acetamiprid; three Imidacloprid metabolites, 5-hydroxy-Imidacloprid, 4,5-dihydroxy-imidacloprid, 4,5-dehydro-Imidacloprid; a common metabolite of acetamiprid and Imidacloprid, N-(6-chloronicotinoyl)-glycine; and two clothianidin metabolites, N-desmethyl-clothianidin, N-(2-(methylsulfanyl)thiazole-5-carboxyl)-glycine, as well as acetamiprid, were detected in the urine of three cases. The result of the quantitative analysis showed N-desmethyl-acetamiprid was determined in the urine of one case, which had been collected on the first visit, at a concentration of 3.2 ng/mL. This is the first report on the qualitative and quantitative detection of N-desmethyl-acetamiprid in the human urine. The results suggest that the one case with detection of N-desmethyl-acetamiprid was exposed to acetamiprid through the consumption of contaminated foods. Urinary N-desmethyl-acetamiprid, as well as 5-hydroxy-Imidacloprid and N-desmethyl-clothianidin, may be a good biomarker for neonicotinoid exposure in humans and warrants further investigation.

Trends in the application of high-resolution mass spectrometry for human biomonitoring: An analytical primer to studying the environmental chemical space of the human exposome

“…These extractions largely capture a range of chemicals across the polarity spectrum. Taira et al ((Taira et al, 2013)) used a combination of neutral, acidic, and basic SPE for profiling 27 metabolites of neonicotinoid pesticides in human urine. Specific SPE conditions were applied to retain and extract acidic neonicotinoid metabolites such as AM-2, IM-1, CM-1, basic ones such as AM-6, IM-10, and neutrals such as CM-2, CM-7, etc.…”

“…Specific SPE conditions were applied to retain and extract acidic neonicotinoid metabolites such as AM-2, IM-1, CM-1, basic ones such as AM-6, IM-10, and neutrals such as CM-2, CM-7, etc. (Taira et al, 2013). Similarly, Swinton et al (Swinton DJ., 2011) used Oasis HLB and MCX mixed-mode cartridges for extracting nicotine and its metabolites in human urine.…”

“…For example, biomarkers of exposure and stress in diesel engine exhaust-exposed workers were assessed by analyzing urine samples for mono-hydroxylated polycyclic aromatic hydrocarbons with HPLC and etheno-DNA adducts A and C with UHPLC coupled with mass spectrometer detection techniques (Shen et al, 2016a). Trends in the UHPLC applications were reviewed recently (Fekete et al, 2014) and applied to environmental chemicals in human matrices (Diaz et al, 2012, Rotander et al, 2015, Taira et al, 2013, Wang et al, 2014a, Wu et al, 2012). UHPLC has been widely used in other applications such as food (Frenich et al, 2014) and water analysis (Hernández et al, 2014), and metabolism studies (Spaggiari et al, 2014, Zhao and Li, 2014).…”

“…Table 1 presents studies using LC-TOF MS or LC-QqTOF MS for studying human exposures to a broad spectrum of environmental chemicals (Baduel et al, 2015, Cortejade et al, 2016, Diaz et al, 2012, Andra et al, 2015), and specifically for polycyclic aromatic hydrocarbons (Bouchard et al, 2009, Marchese et al, 2004), pesticides/insecticides (Cequier et al, 2014, McMahen et al, 2015, Taira et al, 2013, Yamaguchi et al, 2012), drugs (Chittamma et al, 2013, Pragst et al, 2013, Ristimaa et al, 2010, Marin et al, 2014), polyfluorinated chemicals (Eom et al, 2014, Rotander et al, 2015), environmental tobacco smoke (Swinton DJ., 2011), antibiotics (Wang et al, 2015, Wang et al, 2014a), and personal care products (Wu et al, 2012). GC-TOF MS or GC-QqTOF MS was primarily applied for studying human exposures to persistent organic chemicals (Hernández et al, 2009b, Kazda et al, 2004, Focant et al, 2004, Megson et al, 2015, Fan et al, 2014).…”

Neonicotinoids and their Metabolites in Human Biomonitoring: A Review

“…The same group two years later investigated NNDs metabolites in human urine of 3 patients suspected of subacute exposure to NNDs (Taira et al, 2013). This work came to fi ll gaps of the previous work, such as the non-inclusion of other metabolites of key members of NNDs family (showing selected metabolites of IMI, ACET, and CLOTH).…”