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A set of quality assurance/quality control (QA/QC) criteria for nontargeted measurement of pesticide exposure markers in a large-scale study of human urine has been proposed and applied across five laboratories within the HBM4EU project. Quality control material, including reference standards and fortified pooled urine samples (QC urine) were prepared in a centralized way and distributed across participants to monitor analytical performance and consistency of the liquid chromatography coupled to high-resolution mass spectrometry data generated with a harmonized workflow. Signal intensities, mass accuracy, and retention times of selected QA/QC markers covering a broad range of physicochemical properties were monitored across QC solvent standards, QC urine samples, study urine samples, and procedural blanks, setting acceptance thresholds for repeatability and accuracy. Overall, results showed high repeatability of the collected data. The RSDs of the signal intensities were typically below 20–30% in QC and study samples, with good stability of the chromatographic separation (retention time drift within 2–4 s intrabatch and 5 s interbatch) and excellent mass accuracy (average error < 2 ppm). The use of the proposed criteria allowed for the identification of handling errors, instrumental issues, and potential batch effects. This is the first elaboration of harmonized QA/QC criteria applied across multiple laboratories to assess the quality of data generated by nontargeted analysis of human samples.

Pesticides have contributed significantly to increases in food production over the last few decades. In the European Union (EU), nearly 500 active substances have been approved for use as pesticides. The EU has one of the highest pesticide use in the world, with 374 000 tons being sold annually. Around 90% of pesticide sales can be linked to the agricultural sector. The pesticides used in agriculture, also known as Plant Protection Products (PPP), are applied to soil to prevent or combat the growth of undesired plants that compete with crops for resources, or to crops to combat organisms that can cause damage and reduce crop yields. There are several benefits associated with pesticides, the main ones relate to increasing yields, improving food security, and positively impacting the regional and national economies. On the other hand, intensive and widespread use of pesticides raises serious environmental and human health concerns. This is because substantial amounts of the pesticides applied in agriculture are released into the environment during or after application, and several pesticides (and/or their degradation products) are toxic to non-target-species, persistent in the environment, and accumulate through food chains. The high frequency of reports, increased diversity, and severity of negative effects of some pesticides raise serious concerns about the protection level of the current pesticide regulatory systems. The EU has the strictest system in the world but even it has shortcomings. The main problems relate to the low representativity of pre-approval risk assessments, the effective applicability of precautionary principles, and the limited post-approval monitoring of pesticide risks.Chapter 2 focuses on the limited post-approval monitoring data point, more specifically in soil, a compartment where pesticide data is particularly scarce and fragmented. We analysed the occurrence and levels of 76 pesticide residues in 317 agricultural topsoil samples from the

Although the exposure assessment of chemicals of emerging concern (CECs) has taken a decisive step forward through advances in (bio)informatics, statistics, and the development of highly sophisticated analytical instruments, the lack of standardisation and harmonisation of analytical workflows and method performance assessment for suspect and non-target screening hampers the interpretation of results, their comparability and thus, its transmission to policymakers. To date, unlike in other research fields such as forensics or food analysis, there is a lack of guidelines for non-target analysis in human risk assessment and quality assurance and quality control (QA/QC) protocols. Moreover, the majority of efforts have been focused on the development and implementation of QA/QC actions for data acquisition, data analysis and mining, largely neglecting the sample preparation necessary for determination of CECs by suspect and non-target screening methods.In this article, we propose a set of QA/QC measures that covers sampling, sample preparation and data acquisition, as an aspect of work conducted within the European Biomonitoring for Europe initiative (HBM4EU). These measures include the use of standardised terminology and the implementation of dedicated QA/QC actions in each stage of the analytical process. Moreover, a framework for the analytical performance assessment has been developed for the first time for the identification of CECs in human samples by suspect and non-target approaches. Adoption of the actions proposed here for the identification of CECs in human matrices can significantly improve the comparability of reported results and contribute to the (challenging) Exposome research field.

In this review, five strategies to estimate mycotoxin exposure of a (sub-)population via food, including data collection, are discussed with the aim to identify the added values and limitations of each strategy for risk assessment of these chemicals. The well-established point estimate, observed individual mean, probabilistic and duplicate diet strategies are addressed, as well as the emerging human biomonitoring strategy. All five exposure assessment strategies allow the estimation of chronic (long-Term) exposure to mycotoxins, and, with the exception of the observed individual mean strategy, also acute (short-Term) exposure. Methods for data collection, i.e. food consumption surveys, food monitoring studies and total diet studies are discussed. In food monitoring studies, the driving force is often enforcement of legal limits, and, consequently, data are often generated with relatively high limits of quantification and targeted at products suspected to contain mycotoxin levels above these legal limits. Total diet studies provide a solid base for chronic exposure assessments since they provide mycotoxin levels in food based on well-defined samples and including the effect of food preparation. Duplicate diet studies and human biomonitoring studies reveal the actual exposure but often involve a restricted group of human volunteers and a limited time period. Human biomonitoring studies may also include exposure to mycotoxins from other sources than food, and exposure to modified mycotoxins that may not be detected with current analytical methods. Low limits of quantification are required for analytical methods applied for data collection to avoid large uncertainties in the exposure due to high numbers of left censored data, i.e. with levels below the limit of quantification.

The ethyl acetate-based multi-residue method for determination of pesticide residues in produce has been modified for gas chromatographic (GC) analysis by implementation of dispersive solid-phase extraction (using primary-secondary amine and graphitized carbon black) and large-volume (20 μL) injection. The same extract, before clean-up and after a change of solvent, was also analyzed by liquid chromatography with tandem mass spectrometry (LC-MS-MS). All aspects related to sample preparation were re-assessed with regard to ease and speed of the analysis. The principle of the extraction procedure (solvent, salt) was not changed, to avoid the possibility invalidating data acquired over past decades. The modifications were made with techniques currently commonly applied in routine laboratories, GC-MS and LC-MS-MS, in mind. The modified method enables processing (from homogenization until final extracts for both GC and LC) of 30 samples per eight hours per person. Limits of quantification (LOQs) of 0.01 mg kg-1 were achieved with both GC-MS (full-scan acquisition, 10 mg matrix equivalent injected) and LC-MS-MS (2 mg injected) for most of the pesticides. Validation data for 341 pesticides and degradation products are presented. A compilation of analytical quality-control data for pesticides routinely analyzed by GC-MS (135 compounds) and LC-MS-MS (136 compounds) in over 100 different matrices, obtained over a period of 15 months, are also presented and discussed. At the 0.05 mg kg-1 level acceptable recoveries were obtained for 93% (GC-MS) and 92% (LC-MS-MS) of pesticide-matrix combinations. © 2007 Springer-Verlag.

For ten years RIKILT, Wageningen UR in cooperation with the Netherlands Food and Consumer Product Safety Authority (NVWA) has monitored the use of pesticides in the production of fruits, vegetables, and ornamentals during the growing season.