Determination of organochlorine pesticide residues in fatty foods: A critical review on the analytical methods and their testing capabilities

New sorbent-based hydrophobic alginic acid derivatives for fat removal in multi-pesticide residues: analysis of a fatty food sample

Hydrophobic alginic acid derivatives were synthesized with various aliphatic hydrocarbon chains for fat removal in an analysis of multi-pesticide residues in a fatty food sample. First, alginic acid was chemically modified using eco-friendly ultrasound-assisted esterification with different alcohols, namely, hydrophobic alginic acid-methanol (HAA-C1), hydrophobic alginic acid-butanol (HAA-C4), and hydrophobic alginic acid-octadecanol (HAA-C18). The degree of esterification (DE) was determined by titration, and the results ranged from 57.3% to 63.7%. The physicochemical properties of the synthesized hydrophobic alginic acids (HAAs) were studied using FT-IR, XRD, TGA, and FE-SEM. Subsequently, the performance of the HAAs was checked and evaluated for the removal of fat from a fatty food sample by calculating the fat removal percentage and the determination of 214 pesticide residues in the fatty food sample. For the fat removal percentage application, the HAAs were able to efficiently remove between 77% and 83% of the fat; HAA-C18 had the highest percentage. Regarding the pesticide residue application, HAAs were also able to remove the fat content from the fatty food sample without a significant effect on the pesticide substances. The recoveries of the detected pesticide compounds were between 80% and 120% for all HAAs. However, there were various missing pesticide compounds for HAAs. The number of missing pesticide compounds was 19, 6, and 33 for HAA-C1, HAA-C4, and HAA-C18, respectively. HAA-C4 had medium hydrophobicity and it lost fewer pesticides than the other HAAs. This was because the multi-pesticide mixture had various classes of chemical structure; hence, it had different polarity powers. We concluded that HAAs are developable and applicable to be safely used as a green material in diverse fatty food sample analysis applications.

Organochlorine pesticides in vegetable oils: An overview of occurrence, toxicity, and chromatographic determination in the past twenty-two years (2000-2022)

Organochlorine pesticides (OCPs) are used globally to control pests in the food industry. However, some have been banned due to their toxicity. Although they have been banned, OCPs are still discharged into the environment and persist for long periods of time. Therefore, this review focused on the occurrence, toxicity, and chromatographic determination of OCPs in vegetable oils over the last 22 years (2000-2022) (111 references).Literature search shows that OCPs kill pests by destroying endocrine, teratogenic, neuroendocrine, immune, and reproductive systems. However, only five studies investigated the fate of OCPs in vegetable oils and the outcome revealed that some of the steps involved during oil processing introduce more OCPs. Moreover, direct chromatographic determination of OCPs was mostly performed using online LC-GC methods fitted with oven transfer adsorption desorption interface. While indirect chromatographic determination was favored by QuEChERS extraction technique, gas chromatography frequently coupled to electron capture detection (ECD), gas chromatography in selective ion monitoring mode (SIM), and gas chromatography tandem mass spectrometry (GC-MS/MS) were the most common techniques used for detection. However, the greatest challenge still faced by analytical chemists is to obtain clean extracts with acceptable extraction recoveries (70-120%). Hence, more research is still required to develop greener and selective extraction methods toward OCPs, thus improving extraction recoveries. Moreover, advanced techniques like gas chromatography high resolution mass spectrometry (GC-HRMS) must also be explored. OCPs prevalence in vegetable oils varied greatly in various countries, and concentrations of up to 1500 µg/kg were reported. Additionally, the percentage of positive samples ranged from 1.1 to 97.5% for endosulfan sulfate.

Methods for the analysis of endocrine disrupting chemicals in selected environmental matrixes

Endocrine disrupting chemicals (EDCs) are heterogenous in structure, chemical and physical properties, and their capacity to partition into various environmental matrixes. In many cases, these chemicals can disrupt the endocrine systems of vertebrate and invertebrate organisms when present at very low concentrations. Therefore, sensitive and varied analytical methods are required to detect these compounds in the environment. This review summarizes the analytical methods and instruments that are most used to monitor for EDCs in selected environmental matrixes. Only those matrixes for which there is a clear link between exposures and endocrine effects are included in this review. Also discussed are emerging methods for sample preparation and advanced analytical instruments that provide greater selectivity and sensitivity.

Critical Assessment of Clean-Up Techniques Employed in Simultaneous Analysis of Persistent Organic Pollutants and Polycyclic Aromatic Hydrocarbons in Fatty Samples

Interference of residual lipids is a very common problem in ultratrace analysis of contaminants in fatty matrices. Therefore, quick and effective clean-up techniques applicable to multiple groups of analytes are much needed. Cartridge and dispersive solid-phase extraction (SPE and dSPE) are often used for this purpose. In this context, we evaluated the lipid clean-up efficiency and performance of four commonly used sorbents—silica, C18, Z-Sep, and EMR-lipid—for the determination of organic pollutants in fatty fish samples (10%) extracted using ethyl acetate or the QuEChERS method. Namely, 17 polychlorinated biphenyls (PCBs), 22 organochlorine pesticides (OCPs), 13 brominated flame retardants (BFRs), 19 per- and polyfluoroalkyl substances (PFAS), and 16 polycyclic aromatic hydrocarbons (PAHs) were determined in this study. The clean-up efficiency was evaluated by direct analysis in real time coupled with time-of-flight mass spectrometry (DART-HRMS). The triacylglycerols (TAGs) content in the purified extracts were significantly reduced. The EMR-lipid sorbent was the most efficient of the dSPE sorbents used for the determination of POPs and PAHs in this study. The recoveries of the POPs and PAHs obtained by the validated QuEChERS method followed by the dSPE EMR-lipid sorbent ranged between 59 and 120%, with repeatabilities ranging between 2 and 23% and LOQs ranging between 0.02 and 1.50 µg·kg⁻¹.

Comparison of Different d-SPE Sorbent Performances Based on Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) Methodology for Multiresidue Pesticide Analyses in Rapeseeds

Pesticide extraction in rapeseed samples remains a great analytical challenge due to the complexity of the matrix, which contains proteins, fatty acids, high amounts of triglycerides and cellulosic fibers. An HPLC-MS/MS method was developed for the quantification of 179 pesticides in rapeseeds. The performances of the quick, easy, cheap, effective, rugged, and safe (QuEChERS) method were evaluated using different dispersive solid-phase extraction (d-SPE) sorbents containing common octadecylsilane silica/primary-secondary amine adsorbent (PSA/C18) and new commercialized d-SPE materials dedicated to fatty matrices (Z-Sep, Z-Sep+, and EMR-Lipid). The analytical performances of these different sorbents were compared according to the SANTE/12682/2019 document. The best results were obtained using EMR-Lipid in terms of pesticide average recoveries (103 and 70 of the 179 targeted pesticides exhibited recoveries within 70-120% and 30-70%, respectively, with low RSD values). Moreover, the limits of quantification (LOQ) range from 1.72 µg/kg to 6.39 µg/kg for 173 of the pesticides. Only the recovery for tralkoxydim at 10 μg/kg level was not satisfactory (29%). The matrix effect was evaluated and proved to be limited between -50% and 50% for 169 pesticides with this EMR-Lipid and freezing. GC-Orbitrap analyses confirmed the best efficiency of the EMR-Lipid sorbent for the purification of rapeseeds.

Simultaneous Analysis of Fenpropimorph and Fenpropimorph Acid in Six Different Livestock Products Using a Single-Sample Preparation Method Followed by Liquid Chromatography-Tandem Mass Spectrometry

Pesticides in livestock products must be measured to ensure food safety. We developed a single-sample preparation method followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) for simultaneous determination of fenpropimorph and fenpropimorph acid in six different livestock products. The extraction method was a modification of the quick, easy, cheap, effective, rugged, and safe (QuEChERS) method and was validated according to the CODEX guidelines. The matrix-matched calibration curves for fenpropimorph and fenpropimorph acid exhibited good linearity, with coefficients of determination (R2 values) higher than 0.998. The limit of detection (LOD) and the limit of quantitation (LOQ) were 1.25 and 5.0 µg kg-1, respectively. The average recovery values ranged from 61.5% to 97.1% for samples fortified to the LOQ, 2 × LOQ, and 10 × LOQ. The method fully complied with the CODEX guidelines and was successfully applied to real samples obtained from domestic markets.

Evaluation of Different Models for Non-Destructive Detection of Tomato Pesticide Residues Based on Near-Infrared Spectroscopy

In this study, the possibility of non-destructive detection of tomato pesticide residues was investigated using Vis/NIRS and prediction models such as PLSR and ANN. First, Vis/NIR spectral data from 180 samples of non-pesticide tomatoes (used as a control treatment) and samples impregnated with pesticide with a concentration of 2 L per 1000 L between 350-1100 nm were recorded by a spectroradiometer. Then, they were divided into two parts: Calibration data (70%) and prediction data (30%). Next, the prediction performance of PLSR and ANN models after processing was compared with 10 spectral preprocessing methods. Spectral data obtained from spectroscopy were used as input and pesticide values obtained by gas chromatography method were used as output data. Data dimension reduction methods (principal component analysis (PCA), Random frog (RF), and Successive prediction algorithm (SPA)) were used to select the number of main variables. According to the values obtained for root-mean-square error (RMSE) and correlation coefficient (R) of the calibration and prediction data, it was found that the combined model SPA-ANN has the best performance (RC = 0.988, RP = 0.982, RMSEC = 0.141, RMSEP = 0.166). The investigational consequences obtained can be a reference for the development of internal content of agricultural products, based on NIR spectroscopy.

Organochlorine pesticide analysis in milk by gas-diffusion microextraction with gas chromatography-electron capture detection and confirmation by mass spectrometry

Organochlorine pesticides (OCPs) are synthetic compounds less used nowadays due to their toxicity combined with slow degradation which leads to accumulation in the environment. Gas-diffusion microextraction (GDME) was employed prior to gas chromatography with electron capture detection (GC-ECD) and mass spectrometry (GC-MS). For the first time, the low-cost, eco-friendly GDME system was used to extract the OCPs directly from milk samples and associated with GC-ECD. Parameters that affect GDME's performance (extract volume, extraction time, and temperature) were optimized. The calibration curves of all OCPs (α- and β-hexachlorocyclohexane, lindane, hexachlorobenzene, p,p'-DDE, aldrin, dieldrin, and α-endosulfan) had coefficients of determination (r²) ranging from 0.991 to 0.995, and limits of detection (LODs) values ranging from 3.7 to 4.8 µg L^-1. This method also provided satisfactory values for precision with relative standard deviations (RSDs) lower than 10% and recoveries above 90%. As a proof-of-concept, several commercial milk samples were analyzed, aldrin was found in one of them but below the maximum residue limits.

Validation of analytical methods for organochlorine pesticide detection in shellfish and cephalopods by GC-MS/MS

This study validated the analysis of organochlorine pesticides (OCPs) in shellfish and cephalopods using a gas chromatograph equipped with a mass spectrometry (GC-MS/MS), and monitored residual pesticide levels. The QuEChERS method was used to analyze OCPs and was validated by checking the linearity, limit of detection (LOD), limit of quantitation (LOQ), accuracy, and precision. Octopus minor and Venerupis philippinarum, were purchased from four cities in the South Korean peninsula. The LOD values were 0.10-0.80 ng/g in shellfish and 0.21-0.77 ng/g in cephalopods, while the LOQ values were 0.31-2.41 ng/g in shellfish and 0.63-2.33 ng/g in cephalopods. Accuracy ranged from 83.5 to 117.4% and 79.8 to 118.4%, and precision ranged from 0.3 to 27.5% and 1.2 to 27.9%, in shellfish and cephalopods, respectively, conforming to the Codex Alimentarius Commission guidelines. Although residual OCP levels were below detection limits, the QuEChERS method may be effective for analyzing the OCPs in shellfish and cephalopods.

Association Between Leukocyte Telomere Length and Serum Concentrations of PCBs and Organochlorine Pesticides

Exposure to polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) through food, water, and air occurred during the life, which may change telomere length (TL) in peripheral blood leukocytes. The present study was designed to investigate the association between TL and serum levels of PCBs and OCPs in Tehran male's population. Whole blood samples were randomly taken from 300 adult males, aged between 25 and 40 years. TL was determined by real-time PCR to measure the number of the telomere (T) repeats to the number of a single-copy gene (S). We applied the multivariate linear regression model to compare the effect of each lipid adjusted serum levels of PCBs and OCPs congener on the TL, with adjustment for age, body mass index, education, smoking, and food patterns. Each doubling of the nondioxin-like PCBs, dioxin-like PCBs, and OCPs levels were associated with 1.9% [95% confidence interval (CI) - 0.70 to 5.40%], 2.5% (95% CI 0.30-8.3%), and - 2.4% (95% CI - 0.70 to - 6.2%) variation in the TL, respectively. The percent difference in the TL with exposure to nondioxin-like PCBs, dioxin-like PCBs, and OCPs for participants with older than age 37 years were 6.45% (95% CI  2.81-16.50%), 4.52% (95% CI  1.60-10.54%), and - 7.44% (95% CI - 1.55 to - 15.51%), respectively. Exposures to nondioxin-like PCBs (except for PCB 28 and 52) with high chlorine in structure and dioxin-like PCBs were related to longer TLs. Conversely, serum levels of OCPs can be associated with oxidative stress and systemic inflammation that lead to telomere shortening.

Determination of organochlorine priority substances in fish tissue: Optimisation of the clean-up step balancing removal of lipids with analytes' recovery

Quality-assessed analytical methods are required to determine organic priority substances (PS) in biota for the monitoring of the water status according to the EU Water Framework Directive. Although the literature describes several analytical methods to determine these substances in fish, discussion about the efficiency of the clean-up procedures to remove the lipids in the final organic extract (and decrease the disturbance of co-extractives at the detection step) is scarce. This work highlights the results of the development of an analytical method for organochlorines in fish tissue focused on the optimisation of the clean-up step in order to obtain a final extract with the lowest amount of lipids. The efficiency of the purification of the final extract was assessed by quantifying the removal of co-extractives gravimetrically, by considering the sensitivity of the gas chromatography-mass spectrometry (GC-MS) method for the analytes and by assessing the analytes' recovery. An analytical method based on accelerated solvent extraction followed by gel permeation chromatography and dual solid phase extraction (as clean-up steps) and quantification via isotope dilution GC-MS was applied to the analysis of seven PS [α-, β-, γ- and δ-hexachlorocyclohexane (HCH) isomers, pentachlorobenzene (PeCB), hexachlorobenzene (HCB) and hexachlorobutadiene (HCBD)]. A preliminary validation of the method was carried out with satisfactory results for all analytes in terms of intermediate precision (2.9-9.4%, except 11.8% for β-HCH). Repeatability values were satisfactory for α-, γ-HCH, PeCB and HCB (4.3-6.9%), while the obtained results for β-, δ-HCH and HBCD showed the need for further optimisation. Trueness was within the target performance (recovery range: 96.0-107.5%) for all analytes except β- and δ-HCH. Limits of quantification between 0.5 and 3.3 ng/g wet weight were achieved, depending on the analytes. The proposed method can be employed to determine the mentioned PS in fish tissue with up to approximately 6% lipid content. The presented results show the challenges in establishing an analytical method which aims at balancing the required accuracy with the routine applicability (and a minimised impact on the detection system) as needed in the context of environmental monitoring.

Supercritical Fluid Extraction of Pesticides and Insecticides from Food Samples and Plant Materials

The principal intention of this study is presenting the attempts carried out for extracting, separating, and determining of the pesticide and insecticide residues existing in food and plant samples. In this regard, a set of content, including the explanations about the supercritical fluid extraction (SFE), supercritical fluid chromatography, and various types of pesticides are indicated. Besides, the parameters affecting the pesticides extraction composed of temperature, pressure, modifier, drying agent, and so on are discussed. Also, examples of insecticides extraction by SFE technique as an important subset of pesticides are indicated. Along with these items, some interesting works, concerning the innovations implemented in the field of SFE of pesticide and insecticide residues from foodstuff and plants are depicted.

Transfer of Organochlorine Pesticide Residues during Household and Industrial Processing of Ginseng

Ginseng is an important traditional herbal medicine; however, ginseng root may contain pesticide residues that may cause adverse health effects to consumers. Generally, people are more inclined to take the household- or industrial-processed ginseng products, instead of eating them directly. To investigate the intake of pesticides along with ginseng more specifically, we simulated two household processing methods (boiling and brewing) and two industrial processing methods (ethanol refluxing and boiling combined with resin purification) and then calculated the transfer rates of five organochlorine pesticide (OCP) residues in ginseng. The determination of targeted pesticide residues in ginseng was done by gas chromatography-electron capture detector (GC-ECD), and the confirmation was done by gas chromatography-tandem mass spectrometer (GC-MS/MS). The transfer rates of five OCPs during boiling, brewing, ethanol refluxing, and boiling combined with resin purification were 3.44%–34.43%, 1.47%–38.12%, 34.81%–57.0%, and 0–2.91%, respectively. The transfer rates of the OCPs in water extraction (boiling and brewing) were relatively low and would not increase significantly along with two hours of boiling. The OCPs were concentrated during the ethanol refluxing procedure because of the high transfer rates of the OCPs and the reduction of the weight of products. The boiling combined with resin purification method removed the OCPs most effectively. Different ginseng processing methods resulted in variable transfer rates of pesticides, as well as a diverse exposure risk of pesticides to humans. Consequently, it is necessary to concern about the transfer rates of pesticide residues during ginseng processing.

Persistent Organic Pollutants in Food: Contamination Sources, Health Effects and Detection Methods

Persistent organic pollutants (POPs) present in foods have been a major concern for food safety due to their persistence and toxic effects. To ensure food safety and protect human health from POPs, it is critical to achieve a better understanding of POP pathways into food and develop strategies to reduce human exposure. POPs could present in food in the raw stages, transferred from the environment or artificially introduced during food preparation steps. Exposure to these pollutants may cause various health problems such as endocrine disruption, cardiovascular diseases, cancers, diabetes, birth defects, and dysfunctional immune and reproductive systems. This review describes potential sources of POP food contamination, analytical approaches to measure POP levels in food and efforts to control food contamination with POPs.

Development and application of the analytical method for illicit drugs and metabolites in fish tissues

In this study, we developed a screening method for highly accurate and sensitive analysis of 12 illicit drugs and metabolites in fish tissues. The approach was based on ultrasonic-assisted extraction and solid phase extraction, followed by ultra-performance liquid chromatography-tandem mass spectrometry analysis. The homogenized samples were ultrasonic-assisted extracted with 1% acetic acid in methanol followed by SPE cleanup with Oasis MCX cartridge. The method was validated in accordance with the European Medicines Agency guidelines by evaluating the following required parameters: the limits of detection and limits of quantification, linearity, accuracy, repeatability, recovery of extraction, and matrix effect. For the tissues involved in this study, the recoveries ranged from 60% to 127%, and the matrix effect ranged from -19% to 83% with the inter- and intra-day variability below 12%. The method has been successfully applied to wild fish caught from six sampling sites of four urban rivers in Beijing, China. The analysis showed that the target compounds, including amphetamine, 3,4-methylenedioxyamphetamine, codeine and heroin were detected with high detection frequencies. Codeine exhibited the highest bioaccumulation factor (up to 73,986) in the muscle of Crucian carp, while ketamine tended to accumulate in the skin, 3,4-methylenedioxyamphetamine and heroin tended to accumulate in gastrointestinal tract, respectively.

Knowledge and behavior regarding pesticide use: a survey among caregivers of children aged 1-6 years from rural China

Little is known about pesticide exposure risks for children in rural areas in China, many of whom have been left behind by migrant workers. To survey caregivers of children in rural China and assess their pesticide use and disposal methods, the measures were used to protect the children and their perceptions of the adverse effects of pesticides on children's health. Three or four villages in each of Xinhua, Gongan and Sansui Counties in China were selected by random cluster sampling. The main caregivers of children aged 1-6 years were surveyed in face-to-face interviews. The questionnaire used was adapted from the World Health Organization "Exposure to Pesticides: Standard Protocol" survey and similar studies. The study included 464 caregivers (mean age, 46.4 years), who were most commonly the children's grandparents (65.3%). Among the caregivers, 41.9% were educated to middle school level or higher, 45.4% had a household income < 297 USD, and 29.7% had received education/training about pesticide use/adverse health effects in children. The score for caregivers' knowledge of the adverse effects of pesticides on children's health was higher in those who had received education/training (5.1 ± 2.6 vs. 3.4 ± 2.5, P < 0.001). Factors associated with unsafe behaviors during pesticide use included grandparent as the caregiver (odds ratio [OR] 0.551; 95% confidence interval [95% CI] 0.368-0.824; P = 0.004), annual income < 297 USD (OR 0.580; 95% CI 0.395-0.853; P = 0.006), and insufficient health-related education/training (OR 0.436; 95% CI 0.286-0.665; P < 0.001). Improved education and training are needed to promote the safe use of pesticides by caregivers of children in rural China.

Validation Including Uncertainty Estimation of a GC⁻MS/MS Method for Determination of Selected Halogenated Priority Substances in Fish Using Rapid and Efficient Lipid Removing Sample Preparation

A rapid method is proposed for the determination of selected H₂SO₄ stable organic compounds—eight organochlorines (OCs; hexachloro-1,3-butadiene, pentachlorobenzene, hexachlorobenzene, hexachlorocyclohexane—HCH—isomers, heptachlor) and six polybrominated diphenyl ethers (PBDEs; BDE-28, 47, 99, 100, 153, 154)—in fish samples. In the method, a modified QuEChERS (quick, easy, cheap, effective, rugged and safe) sample preparation using pH-tuned dispersive liquid–liquid microextraction (DLLME) and H₂SO₄ digestion fish extract clean-up is followed by gas chromatography–triple quadrupole tandem mass spectrometry (GC–QqQ-MS/MS) analysis. The method was validated in terms of linearity, limits of the method, recovery, accuracy, analysis of standard reference material (NIST SRM 1946), and estimation of combined uncertainty of the measurement (top-down approach). For validation, chub composite samples were used, and subsequently, the method was successfully applied to analysis of real samples of eight fish species. Finally, the method passed the analytical Eco-Scale evaluation as “an acceptable green analysis method”, and showed its advantages (simplicity, rapidity, low cost, high extract clean-up efficiency, good sensitivity) when compared to other reported QuEChERS based methods.

Analysis of 52 pesticides in fresh fish muscle by QuEChERS extraction followed by LC-MS/MS determination

Pesticide pollution in water has been well described; however, little is known on pesticide accumulation by aquatic organisms, and to date, most studies in this line have been focused on persistent organochlorine pesticides. For this reason, a method based on QuEChERS extraction and subsequent liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis has been developed and validated for the determination of 52 medium to highly polar pesticides in fresh fish muscle. Target pesticides were selected on the basis of use and occurrence in surface waters. Quantification is carried out following an isotope dilution approach. The method developed is satisfactory in terms of accuracy (relative recoveries between 71 and 120%), precision (relative standard deviations below 21%) and sensitivity (limits of determination in the pg/g or low ng/g f.w. range for most compounds). The application of the validated methodology to fish specimens collected from the Adige River (Italy) revealed the presence of trace levels of diazinon, dichlorvos and diuron, and measurable levels of metolachlor, quinoxyfen, irgarol, terbutryn, and acetamiprid, but in all cases at concentrations below the default maximum residue level of 10 ng/g established for pesticides not specifically regulated in fish intended for human consumption. Metolachlor and quinoxyfen were both the most ubiquitous and abundant pesticides, in agreement with their high potential for bioaccumulation. Both are toxic to aquatic organisms, and therefore, their potential effects on aquatic ecosystems should be further explored.

Dispersive Solid-Phase Extraction Using Microporous Sorbent UiO-66 Coupled to Gas Chromatography-Tandem Mass Spectrometry: A QuEChERS-Type Method for the Determination of Organophosphorus Pesticide Residues in Edible Vegetable Oils without Matrix Interference

A QuEChERS-type method without matrix interference was designed and developed to determine organophosphorus pesticide residues in edible vegetable oils, based on dispersive solid-phase extraction with cleanup using UiO-66 as sorbent. Microporous UiO-66 directly and selectively adsorbed organophosphorus pesticides and excluded interfering compounds. Clean analytes were obtained by elution and analyzed using gas chromatography-tandem mass spectrometry. The dispersive solid-phase extraction conditions (amount of adsorbent, extraction time, desorption solvent volume, and elution time) were optimized. The limits of detection of the pesticides in vegetable oils were 0.16-1.56 ng/g. Under optimized conditions, the average pesticide recoveries were 81.1-113.5%. The intraday and interday relative standard deviations for analyte recovery were <8.2 and <13.9%, respectively. Thus, the method is reliable and could detect organophosphorus pesticide residues in edible vegetable oils. Furthermore, UiO-66 can be easily recycled and reused at least 10 times, reducing the cost of analysis.

Occurrences and patterns of residual organochlorine pesticides (OCPs) in cultured Chinese mitten crab (Eriocheir sinensis) in China: concentrations, sources, and a human health risk assessment

Seventy Chinese mitten crab samples, encompassing a total of 2100 individuals, were collected from the main production areas in China. The objective was to assess the occurrences and patterns of 23 selected organochlorine pesticides (OCPs) in the edible tissues and assess the associated dietary risk. Concentrations of total residual OCPs in the mitten crabs ranged from 0.72 to 51.51 μg kg^-1, which was comparable to other global aquatic species. Dichlorodiphenyl trichloroethanes (DDTs) and hexachlorocyclohexanes (HCHs) were the two main contributors of total OCPs, with the detected values ranging from 0.14 to 30.89 μg kg^-1 and 0.23 to 4.04 μg kg^-1, respectively. Source analysis indicated the coexistence of both residual and recent DDT inputs, while there was no indication of HCH usage in the main production area of mitten crab. In terms of dietary risk, at least eight individual mitten crabs per day are permissible for consumption by local residents, indicating low risk from consumption. The results presented herein should guide the production and consumption of mitten crab, as well as promote the sustainable development of aquaculture in China.

Application of the QuEChERS method for the determination of organochlorine pesticide residues in Brazilian fruit pulps by GC-ECD

The Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) method was applied to the extraction of 14 organochlorine pesticides (OCPs) residues from commercial fruit pulps available in supermarkets in Fortaleza, Northeastern Brazil. The analyses were carried out by gas chromatography (GC), coupled to an electron-capture detector (ECD), and were confirmed by GC-tandem mass spectrometry (MS). The parameters of the analytical method, such as accuracy, precision, linear range, limits of detection and quantification, were determined for each pesticide. The results showed good linearity (R² ≥ 0.9916) and the overall average recoveries were considered satisfactory obtaining values between 69 and 110%, RSD of 2-15 %, except for hexachlorobenzene (HCB) in açai, acerola and guava pulp samples. The OCPs were detected in guava (α-HCH; lindane) and soursop (α, β-HCH isomers) samples. The QuEChERS method and GC-ECD were successfully used to analyze OCPs in commercially available Brazilian fruit pulps and can be applied in routine analytical laboratories.

Polychlorinated biphenyls and organochlorine pesticides in Tiber River and Estuary: Occurrence, distribution and ecological risk

The polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) pollution in the Tiber River and its environmental impact on the Tyrrhenian Sea (Central Mediterranean Sea) were estimated. 32 PCBs and 17 OCPs (aldrin, α-BHC, β-BHC, δ-BHC, lindane, p,p'-DDD, p,p'-DDE, p,p'-DDT, dieldrin, endosulfan I, endosulfan II, endosulfan sulfate, endrin, endrin aldehyde, heptachlor, heptachlor epoxide, methoxychlor) were determined in the water dissolved phase (DP), suspended particulate matter (SPM) and sediment samples. Total concentrations of PCBs ranged from 0.54 to 74.75ngL(-1) in water (sum of DP and SPM) and from 3.73 to 79.30ngg(-1) dry weigh in sediment samples; while the concentrations of total OCPs collected in water (sum of DP and SPM) ranged from 0.07 to 7.04ngL(-1) and from 0.66 to 10.02ngg(-1) dry weigh in sediment samples. Contaminant discharges into the sea were calculated in about 227.08kgyear(-1) for PCBs and 24.91kgyear(-1) for OCPs, showing that this river should account as one of the main contribution sources of PCBs and OCPs to the Tyrrhenian Sea. The ∑TEQPCB from the sediment samples ranged from 0.0006 to 0.37ngg(-1) with an average level of 0.13ngg(-1). Based on Sediments Quality Guidelines, biological adverse effects on aquatic ecosystem were rare to occasional for PCB and OCP levels in Tiber water system.

Temporal variations in embryotoxicity of Lake Ontario American eel (Anguilla rostrata) extracts to developing Fundulus heteroclitus

The recruitment of American eel (Anguilla rostrata) juveniles to Lake Ontario (LO), Canada has declined significantly since the 1980s. To investigate the possible contribution of maternally-transferred persistent organic pollutants (POPs) to this decline, this study measured temporal variations in the toxicity of complex organic mixtures extracted from LO American eels captured in 1988, 1998 and 2008 to developing Fundulus heteroclitus exposed by intravitelline (IVi) injection. The 1988 and 1998 eel extracts were most toxic, causing a pattern of sublethal embryotoxic responses similar to those previously reported in F. heteroclitus embryos exposed to single dioxin-like compounds (DLCs): stunted growth, craniofacial deformities, EROD activity induction, and reduced predatory capacities. The potency of extracts declined over time; the only significant effect of the 2008 eel extracts was EROD induction. The chemically-derived TCDD-TEQs of eel extracts, calculated using measured concentrations of some DLCs and their relative potencies for F. heteroclitus, overestimated their potency to induce EROD activity possibly due to interactions among POPs. Other POPs measured in eel extracts (non-dioxin-like PCBs, PBDEs and organochlorinated pesticides) did not appear to be important agonistic contributors to the observed toxicity. The toxicity of the complex mixtures of POPs measured in LO eels may have been underestimated as a result of several factors, including the loss of POPs during extracts preparation and a focus only on short-term effects. Based on the model species examined, our results support the hypothesis that contamination of LO with DLCs may have represented a threat to the American eel population through ecologically-relevant effects such as altered larval prey capture ability. These results prioritize the need to assess early life stage (ELS) toxicity of DLCs in Anguilla species, to investigate long-term effects of complex eel extracts to ELS of fish, and to develop biomarkers for potential effects in eel ELS sampled in the field.

Toxicokinetics and oxidative stress in Tubifex tubifex exposed to hexachlorocyclohexane isomers

In this study, Tubifex tubifex (Oligochaeta, Tubificida) was exposed to hexachlorocyclohexane isomers in an aquatic environment to study the bioaccumulation and elimination of these chemicals, and oxidative stress in this organism.

Pesticide residues in chicken eggs - A sample preparation methodology for analysis by gas and liquid chromatography/tandem mass spectrometry

A sample preparation method was developed for the analysis of chicken eggs to determine 97 GC and 81 LC amenable residues, including organophosphates, organochlorines, pyrethroids, triazoles, carboxyl-containing compounds, and the indicator PCBs. Hereby, considerations were given to the recoveries of the analytes, the method's suitability for routine analysis, and the assessment of the clean-up effect, for which a simple thin layer chromatography was implemented to visualize the most important lipid classes. The procedure consisted of (I) the extraction by matrix solid phase dispersion, and the clean-up by means of (II) small-scale gel permeation chromatography (GPC) and (III) two different solid phase extractions (SPE) for GC and LC amenable analytes, as well as (IV) the quantification using GC-MS/MS and LC-MS/MS. Cyclohexane/ethyl acetate was chosen as extraction solvent due to its suitability for extracting strong non-polar but also more polar analytes. The classical GPC was scaled down to ensure a 50% lower solvent consumption. The comprehensive investigation of conventional and modern zirconium-oxide-coated SPE materials resulted in the selection of octadecyl-modified silica (C18) combined with primary secondary amine using acetonitrile as elution solvent for GC amenable analytes and pure C18 in combination with acidified methanol for LC amenable pesticides. Compared to the currently established EN 1528 method the sample preparation proposed offered a higher sample throughput and a lower solvent consumption. Furthermore, for the first time the clean-up effectiveness of the sample preparation steps was documented as shown by means of thin-layer chromatography. The validation of chicken eggs proved the fulfillment of the quality control criteria for 164 of the 178 analytes tested, mostly at the lowest validated level of 5μg/kg for pesticides and 0.5μg/kg for the single indicator PCBs. However, the analysis of strongly polar analytes was still problematic, which could be attributed to the extraction and the GPC step. Nevertheless, the successful investigation of EU proficiency test materials (EUPT AO 07-09) confirmed the comparability of the results with the currently established sample preparation procedures and demonstrated the potential of the applicability of the presented method to other matrices as exemplified for lean poultry meat and fatty liquid cream.