Biomonitoring method for neonicotinoid insecticides in urine of non-toilet-trained children using LC-MS/MS

ABSTRACT

There is a growing appreciation of the importance of determining chemical exposure levels in early childhood, as well as in embryonic and foetal life, which are now widely believed to be essential for gaining insight into potential health risks associated with these chemicals. To facilitate the assessment of exposure to neonicotinoid insecticides (NEOs) in non-toilet-trained children, a new method using disposable diapers (nappies) was developed for the simultaneous determination of the NEOs acetamiprid and its metabolite N-desmethylacetamiprid, clothianidin, dinotefuran, imidacloprid, thiacloprid, and thiamethoxam (NEO biomarkers). The urine absorbed in disposable diapers was extracted with acetone (diaper urine) and was cleaned using a solid-phase extraction column, before analysis with LC-MS/MS. The absolute recoveries of NEO biomarkers were 19–50%. Good results were observed for the linearity of the matrix-matched calibration curves (r² = 0.983–0.996; concentration range LOQ-20 µg L⁻¹) and the precision of intra-day (% relative standard deviation (%RSD): 3.3–12.7%) and inter-day (%RSD: 4.3–19.5%) analyses. The lowest and highest limits of detection of the developed method were 0.07 µg L⁻¹ for acetamiprid and 0.75 µg L⁻¹ for clothianidin. The developed method was applied for the evaluation of fifty diapered three-year-old children in Japan. Importantly, the study revealed relatively high detection rates for dinotefuran and N-desmethylacetamiprid; 84% and 78% respectively. The highest geometric mean of dinotefuran urinary concentration was 2.01 µg L⁻¹. Thus, a method for determining NEO biomarkers in urine extracted from disposable diapers was established. This is the first report on the simultaneous quantitative analysis of NEO biomarkers of diaper-absorbed urine samples.

KEYWORDS:

• Neonicotinoid
• diaper
• urine
• LC-MS/MS
• biomarkers

Disclosure statement

There are no conflicts of interest to declare.

Additional information

Funding

This study was conducted as an adjunct study of Japan Environment and Children’s Study (JECS). JECS was funded by the Ministry of the Environment, Japan, and the present study was supported by the Environment Research and Technology Development Fund (5-1551) of the Ministry. The findings and conclusions of this presentation are solely the responsibility of the authors and do not represent the official views of the funding agency. We are indebted to the study participants and the research staff in JECS-A for their dedication, and local governments (cities of Nagoya and Ichinomiya) for their encouraging cooperation toward this study. This work was also supported in part by Grants-in-Aid for Scientific Research [26460799, 19H01078] from the Japan Society for the Promotion of Science and by Nasu Fund for the Advancement of Young Scientist Research.