A liquid chromatography mass spectrometry-based method to measure organophosphorous insecticide, herbicide and non-organophosphorous pesticide in grape and apple samples

The LC-MS/MS with Quick, Easy, Cheap, Effective, Rugged and safe method was used for analysis of eighteen pesticides in fruit samples. This method was found to be accurate (≥99%), as it possessed limits of detection in the 0.002-0.087 ranges respectively. The coefficients of variations (≥0.9999) were less than 2% at the low ng g⁻¹ concentration. Mean recoveries ranged between 97 and 101%, and % RSD were below 5%. The imidacloprid mean concentrations of red grapes (125.124 ng g⁻¹) and green grapes (702.030 ng g⁻¹) differed significantly (p < 0.05) between the grapes. Similarly, the fenitrothion mean concentration of red grapes (143.66 ng g⁻¹) and green grapes (51.554 ng g⁻¹) differed significantly (p < 0.001) between the fruits. The average concentration of quinalphos was 4.317 and 1.389 ng g⁻¹ differed significantly (p < 0.01) between the grapes. In apples imidacloprid, quinalphos, triazophos, ethion and acephate were also present. This study may be helpful in developing a regional exposure database and in the facilitation of health risk assessment due to pesticide exposure.     

Titanium dioxide-mediated photocatalysed degradation of few selected organic pollutants in aqueous suspensions

The photocatalytic degradation of maleic hydrazide (1), propham (2), tebuthiuron (3), propachlor (4), chlortoluron (5), thiram (6), phenoxyacetic acid (7), 2,4,5-trichlorophenoxy acetic acid (8), 4-chlorophenoxy acetic acid (9), uracil (10), 5-bromouracil (11) and bromothymol blue (12) have been investigated in aqueous suspensions of titanium dioxide (TiO₂) under a variety of conditions. The degradation was studied by monitoring the change in substrate concentration employing UV spectroscopic analysis technique and depletion in total organic carbon (TOC) content as a function of irradiation time. The degradation kinetics of the compounds were investigated under different conditions, such as types of TiO₂, pH, catalyst concentration, substrate concentration, temperature and in the presence of different electron acceptors, such as hydrogen peroxide (H₂O₂), potassium persulphate (K₂S₂O₈), ammonium persulphate (NH₄)₂S₂O₈ and potassium bromate (KBrO₃) besides molecular oxygen. TiO₂ Degussa P25 was found to be more efficient photocatalyst for the degradation of the model compounds as compared with other photocatalysts. The degradation products were analysed using GC/MS analysis technique and probable pathways for the formation of different products have been proposed.     

Is biological treatment a viable alternative for micropollutant removal in drinking water treatment processes?

In western societies, clean and safe drinking water is often taken for granted, but there are threats to drinking water resources that should not be underestimated. Contamination of drinking water sources by anthropogenic chemicals is one threat that is particularly widespread in industrialized nations. Recently, a significant amount of attention has been given to the occurrence of micropollutants in the urban water cycle. Micropollutants are bioactive and/or persistent chemicals originating from diverse sources that are frequently detected in water resources in the pg/L to μg/L range. The aim of this review is to critically evaluate the viability of biological treatment processes as a means to remove micropollutants from drinking water resources. We first place the micropollutant problem in context by providing a comprehensive summary of the reported occurrence of micropollutants in raw water used directly for drinking water production and in finished drinking water. We then present a critical discussion on conventional and advanced drinking water treatment processes and their contribution to micropollutant removal. Finally, we propose biological treatment and bioaugmentation as a potential targeted, cost-effective, and sustainable alternative to existing processes while critically examining the technical limitations and scientific challenges that need to be addressed prior to implementation. This review will serve as a valuable source of data and literature for water utilities, water researchers, policy makers, and environmental consultants. Meanwhile this review will open the door to meaningful discussion on the feasibility and application of biological treatment and bioaugmentation in drinking water treatment processes to protect the public from exposure to micropollutants.     

Feasibility study for producing a carrot/potato matrix reference material for 11 selected pesticides at EU MRL level: Material processing, homogeneity and stability assessment

The feasibility for producing a matrix reference material for selected pesticides in a carrot/potato matrix was investigated. A commercially available baby food (carrot/potato-based mash) was spiked with 11 pesticides at the respective EU maximum residue limits (MRLs), and further processed by either freezing or freeze-drying. Batches of some 150 units were produced per material type. First, the materials were assessed for the relative amount of pesticide recovered after processing (ratio of pesticide concentration in the processed material to the initially spiked pesticide concentration). In addition, the materials’ homogeneity (bottle-to-bottle variation), and the short-term (1 month) and mid-term (5 months) stability at different temperatures were assessed. For this, an in-house validated GC-EI-MS method operated in the SIM mode with a sample preparation procedure based on the QuEChERS (“quick, easy, cheap, effective, rugged, and safe”) principle was applied. Measurements on the frozen material provided the most promising results (smallest analyte losses during production), and also freeze-drying proved to be a suitable alternative processing technique for most of the investigated pesticides. Both the frozen and the freeze-dried material showed to be sufficiently homogeneous for the intended use, and storage at −20 °C for 5 months did not reveal any detectable material degradation. The results constitute an important step towards the development of a pesticide matrix reference material.     

Development of a fast multiresidue method for the determination of pesticides in dry samples (wheat grains,flour and bran) using QuEChERS based method and GC–MS

In this study a multiresidue method for the determination of 24 pesticides in wheat, white flour and bran using gas chromatography coupled to mass spectrometry with negative chemical ionisation and selected ion monitoring (GC–MS (NCI–SIM)) was developed and validated. The QuEChERS method was used for the extraction of different pesticides. The method was validated evaluating the following parameters: linearity, limit of detention, limit of quantification, matrix effect as well as precision and accuracy, evaluating the percentage of recovery at four different spike levels. The linear range used in the calibration curves was from 1.0 to 100 μg L⁻¹ for wheat and 2.0 to 200 μg L⁻¹ for flour and bran, both with values of r² > 0.99. The recoveries had been considered satisfactory presenting values between 70% and 120% with RSD < 20% for the majority of compounds.     

果蔬及其制品中甲胺磷、乙酰甲胺磷、氧化乐果、久效磷残留量检测

甲胺磷、乙酰甲胺磷、氧化乐果、久效磷是极性大的农药,这几种农药在常规分析检测过程中产生的基质增强效应,严重影响检测结果的准确性,检出限较高,难以满足痕量分析的需要。本文通过采用硅胶柱的吸附、洗脱净化步骤,去除色素和杂质,达到良好的净化效果,同时采用加入分析保护剂的方式,补偿基质增强效应,保证检测结果的准确性。     

Human Exposure to Airborne Pesticides in Homes Treated with Wood Preservatives

Abstract In rooms where pesticides were applied, air was analysed for its biocide content. Inhabitants of investigated homes attributed their health complaints to pesticide exposure in their homes. Airborne pesticides originating from wood preservatives were sampled on polyurethane foams or Tenax TA and analysed after solvent desorption by HRGC with different types of detector. In investigated homes, concentrations of diazinon, phenthoate, phoxim, propoxur, dichlofluanid, endosulfan, permethrin and tributyltinoxide were found between ≤0.002 and 0.347 μg/m³. In one home, four years after pest control, chlorpyrifos amounted to 0.515 μg/m³. Permethrin emission from a wool carpet ranged between 0.013 and 0.060 μg/m³. Vacuum cleaning for ten minutes increased airborne permethrin up to 0.096 μg/m³. In house dust, diazinon, phenthoate and permethrin were determined in concentrations of 0.60 ≤g/g, 181.00 pg/g and 0.14 μg/g dust, respectively. Estimated inhaled pesticides ranged between ≤0.04 and 10.3 μg/day. Dust ingestion contributed to 0.03–36.2 μg/day. Pesticide intake through inhalation and dust ingestion was estimated to range between 4% and 120% of the ADI-value. Based on today's knowledge, toxic effects are not anticipated.     

Concentration of selected persistent organic pollutants in blood from delivering women in South Africa

Environmental exposure to persistent organic pollutants (POPs) may cause detrimental health effects in the population with the developing foetus and infants being at highest risk. This paper reports on the findings of the pilot study that took place in seven geographical regions of South Africa, 96 pregnant women admitted for delivery participated in the study. The following selected POPs were analysed in maternal plasma: 15 polychlorinated biphenyls (PCBs) congeners (IUPAC No. 28, 52, 99, 101, 105, 118, 138, 149, 153, 156, 170, 180, 183, 187, 194); six DDT metabolites (dichlordiphenyltrichloroethane p,p'-DDT and o,p'-DDT; diphenyldichloroethylene p,p'-DDE and o,p'-DDE, dichlorophenylethane p,p'-DDD o,p'-DDD) and other pesticides such as hexachlorocyclohexanes (α-HCH, β-HCH, γ-HCH), hexachlorobenzene (HCB), heptachlor, chlordanes (t-CD and c-CD), nanochlors (t-NC and c-NC) and mirex.The overall results showed large regional differences with the rural site having the lowest levels for all measured contaminants. The levels of PCB congeners were found to be low in all samples and across all sites. DDT metabolites were detected in most participants of this study and large regional differences were evident. Two malaria endemic sites, where indoor residual spraying (IRS) with DDT takes place to control malaria vector, were included in the study. The highest levels of DDTs were measured in the coastal malaria site (Indian Ocean) with geometric means of 5177 ng/g lipid and 1797 ng/g lipid for p,p'-DDE and p,p'-DDT, and 1966 ng/g lipid and 726 ng/g lipid for p,p'-DDE and p,p'-DDT in inland malaria site. γ-HCH was found to be elevated overall, except for the urban community; the highest levels were measured in the inland and coastal malaria sites. p,p'-DDT and γ-HCH were however not correlated, indicating different sources. The high DDT levels in the malaria spraying regions as well as the elevated γ-HCH levels are of concern and call for extended monitoring of women and children in selected regions.     

Inhibitory effects of selected pesticides on peroxidases purified by affinity chromatography

The objective of this study was to determine the in vitro inhibition effects of seven commonly used pesticides including 2,4-d-acid dimethylamine, fenoxaprop-p-ethyl, glyphosate isopropylamine, haloxyfop-p-methyl, cypermethrin, λ-cyhalothrin, and dichlorvos on the peroxidase purified from turnip (Brassica rapa L.) and black radish (Raphanus sativus L.) using 4-amino benzohydrazide affinity column chromatography. The purification factors for the turnip and black radish peroxidases were found to be 263.29-fold (with a yield of 12.89%) and 36.20-fold (with a yield of 6.90%), respectively. Among these compounds, λ-cyhalothrin showed the strongest inhibitory effect against turnip peroxidase (K_i: 1.23 × 10^?2 ± 0.21 × 10^?2 mM) as noncompetitive inhibition. On the other hand, cypermethrin demonstrated the highest inhibition effect against black radish peroxidase (K_i: 2.14 × 10^?2 ± 0.08 × 10^?2 mM) as competitive inhibition.     

Pesticide residues in grapes from vineyards included in integrated pest management in Slovenia

Although the list of pesticides used in integrated pest management (IPM) in grape growing and their annual application rates are limited, we are still confronted with the problem of pesticide residues in grapes. This paper presents the results of pesticide monitoring of 47 samples of wine grapes (Vitis vinifera L.) from the 2006 vintage from vineyards included in IPM. The grape samples were analysed for the presence of 67 pesticides. Among them 20 were allowed in IPM in 2006. Grapes were sampled at harvest. Two internal analytical methods were used for the determination of pesticides: gas chromatography-mass spectrometry (GC-MS) method for the determination of dithiocarbamates and a multi-residue GC-MS method. One grape sample (2.1%) contained no residues or they were below the limit of detection, 28 samples (59.6%) contained residues lower or equal than maximum residue levels (MRLs), and 18 samples (38.3%) exceeded national MRLs for cyprodinil (the concentration range was 0.03–0.40 mg kg^?1 of cyprodinil) and fludioxonil (concentration was 0.03 mg kg^?1 of fludioxonil). Multiple residues were found in 41 samples (87.2%). The highest number of pesticides detected per sample was seven. No violation of pesticides allowed in IPM was observed. Folpet (97.9%), cyprodinil (51.1%), dithiocarbamates (44.7%), chlorothalonil (23.4%), chlorpyriphos (19.1%) and pyrimethanil (14.9%) were the most frequently found pesticides in grapes. Risk assessment showed that the exceeded concentrations of cyprodinil and fludioxonil did not represent any risk for consumer's health (the national estimate of short-term intake as a percentage of the acceptable daily intake was below 100%).