Validation of reliable and selective methods for direct determination of glyphosate and aminomethylphosphonic acid in milk and urine using LC-MS/MS

Simple high-throughput procedures were developed for the direct analysis of glyphosate [N-(phosphonomethyl)glycine] and aminomethylphosphonic acid (AMPA) in human and bovine milk and human urine matrices. Samples were extracted with an acidified aqueous solution on a high-speed shaker. Stable isotope labeled internal standards were added with the extraction solvent to ensure accurate tracking and quantitation. An additional cleanup procedure using partitioning with methylene chloride was required for milk matrices to minimize the presence of matrix components that can impact the longevity of the analytical column. Both analytes were analyzed directly, without derivatization, by liquid chromatography tandem mass spectrometry using two separate precursor-to-product transitions that ensure and confirm the accuracy of the measured results. Method performance was evaluated during validation through a series of assessments that included linearity, accuracy, precision, selectivity, ionization effects and carryover. Limits of quantitation (LOQ) were determined to be 0.1 and 10 µg/L (ppb) for urine and milk, respectively, for both glyphosate and AMPA. Mean recoveries for all matrices were within 89–107% at three separate fortification levels including the LOQ. Precision for replicates was ≤7.4% relative standard deviation (RSD) for milk and ≤11.4% RSD for urine across all fortification levels. All human and bovine milk samples used for selectivity and ionization effects assessments were free of any detectable levels of glyphosate and AMPA. Some of the human urine samples contained trace levels of glyphosate and AMPA, which were background subtracted for accuracy assessments. Ionization effects testing showed no significant biases from the matrix. A successful independent external validation was conducted using the more complicated milk matrices to demonstrate method transferability.     

Environmental contamination, human exposure and body loadings of perfluorooctane sulfonate (PFOS), focusing on Asian countries

Perfluorinated compounds (PFCs) are man-made fluorinated hydrocarbons, which are very persistent in the environment. Since the early 1980s, the usage of PFCs has sharply increased for a wide array of industrial and commercial applications. Being the most important PFC, perfluorooctane sulfonate (PFOS) has received much attention. In the past decades, increasing surveys have been focused on this compound, to study its sources, fates and effects in the environment. According to the large production volume and wide usage in industrial and commercial products in the past, PFOS can be detected in various environmental media and matrix, even in human tissues. This article attempted to review the current status of PFOS contaminations in Asia, focusing on water systems, sediments, wide animals and human tissues. A special section is devoted to examine the pathways of human exposure to this compound, as well as human body loadings of PFOS and their possible association with diseases.     

Persistent organic pollutants (POPs) in human milk: A biomonitoring study in rural areas of Flanders (Belgium)

To collect information on the concentrations of persistent organic pollutants (POPs) in the rural areas in Flanders (Belgium), 84 breastfeeding mothers were recruited in rural communities in East and West Flanders and Flemish Brabant in 2009-2010. Polychlorinated biphenyl (PCB) congeners, organochlorine pesticides, brominated flame retardants, perfluorinated compounds, polychlorinated dibenzodioxines and dibenzofurans, and dioxin-like PCBs were measured in individual milk samples and in a pooled milk sample, while some additional pollutants were only measured in the pooled sample. For most pollutants, the concentrations in this study were lower or comparable to the concentrations measured in the pooled Belgian sample of the WHO human milk study of 2006, except for the pesticides dichlorodiphenyltrichloroethane DDT (+25% for ΣDDT and metabolites) and trans-nonachlor (+94%), and for the brominated flame retardant hexachlorocyclododecane HBCD (+153%). Perfluorinated compounds were for the first time determined in human milk samples from Belgium and the concentrations were comparable to those from other European countries. Also, interesting associations were found between the concentrations of POPs measured in human milk and personal characteristics as well as dietary habits of the study population. PFOS en PFOA concentrations were significantly higher in milk of primiparous participants compared to mothers who gave birth to their second child. Lower brominated PBDE congeners increased with increasing BMI of the mothers (p = 0.01 for BDE 47, p = 0.02 for BDE 99 and p = 0.02 for BDE 100). Participants consuming milk or dairy products daily had significant higher concentrations of ΣDDTs (p = 0.03) and oxychlordane (p = 0.047) in their human milk samples.     

Monitoring of environmental contaminants in raw bovine milk and estimates of dietary intakes of children in South Korea

Persistent organic pollutants (POPs) are ubiquitous residual contaminants in the environment and in the food chain. Milk is an important matrix for monitoring POP contamination. This study determined the concentrations of POPs including polybrominated diphenyl ethers (PBDEs), hexachlorobenzene (HCB), polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), and dioxin-like polychlorinated biphenyls (DL-PCBs) in raw bovine milk, and the data was used to estimate dietary intakes in South Korea. The average concentrations of PBDEs, HCB, PCDD/Fs, and DL-PCBs in raw milk were 0.29 ng g⁻¹ fat, 0.50 ng g⁻¹ fat, 0.27 pg TEQ g⁻¹ fat, and 0.33 pg TEQ g⁻¹ fat, respectively. No significant relationship was found between the concentrations of analytes and the regions sampled. The dietary intakes of PBDEs from the consumption of milk was calculated to be 0.26, 0.10, and 0.05 ng kg⁻¹ bw d⁻¹ for the group of ages 0–6, 7–12, and 13–19, respectively. The dietary intakes of HCB was calculated to be 0.44, 0.16, and 0.09 ng kg⁻¹ bw d⁻¹ for the group of ages 0–6, 7–12, and 13–19, respectively. The dietary intakes of PCDD/Fs and DL-PCBs was calculated to be 0.78, 0.29, and 0.16 pg TEQ kg⁻¹ bw d⁻¹ for the group of ages 0–6, 7–12, and 13–19, respectively. These results indicated that the residual levels of PBDEs, HCB, PCDD/Fs, and DL-PCBs in raw bovine milk were within safe levels.     

Organochlorine compounds,nitro musks and perfluorinated substances in breast milk – Results from Bavarian Monitoring of Breast Milk 2007/8

The aim of the Bavarian Monitoring of Breast Milk (BAMBI) project was to examine 10 organochlorine pesticides (OPs), 3 nitro musks, 6 indicator polychlorinated biphenyls (PCBs), 7 polychlorinated dibenzo-p-dioxins (PCDDs), 10 polychlorinated dibenzofurans (PCDFs), 12 dioxin-like PCBs (dl-PCBs) and several perfluorinated alkyl compounds in breast milk samples. A total of 516 breast milk samples were collected from seven regions in Bavaria and were analyzed by means of GC/ECD, GC/HRMS, and LC/MS-MS.     

Presence of PAHs in milk of industrial farms from Tizayuca,Hidalgo, Mexico

The objective of this study was to determine the concentrations of polycyclic aromatic hydrocarbons (PAHs) in cow's milk from industrial farms that are located near an industrial park in Hidalgo, Mexico. It was found that the concentrations of PAHs in the raw milk of cattle from industrial farms have increased in recent years. Composite samples were collected between 2008 and 2010 and analysis carried out according to 8100 EPA procedures and analyzed by gas chromatography with FID detection. The results show that combustion PAHs were mostly Ace, Acy, and Fla (0.25, 0.32, and 0.22 µg g^?1, respectively). Diagnostic ratios were used to show that the probable sources were grass and fuel combustion. The sum of concentrations of 16 individual PAHs did not breach permissible levels in milk (25 µg g^?1 according to the United States EPA), indicating a limited health risk to animals and humans in the study area. The industrial park has adequate pollutant emission regulations.     

基于生命周期视角的种养一体化奶牛场环境经济效益评估

准确评估种养一体化奶牛场的经济性能与环境绩效,是相关支持政策制定的基础,也是促进奶业低碳生产的关键.本文基于生命周期视角,对非种养一体化奶牛场（non-IPBS）和种养一体化奶牛场（IPBS）养殖过程中的温室气体排放、能源消耗、水消耗、土地占用等环境成本和经济效益进行评估.结果表明,non-IPBS生产1t标准牛奶（FPCM）的净收益为1427元,而IPBS的实际净收益提高7%,如果青贮玉米自给率从当前的32%提升到100%,则实际净收益将提高19%,同时,该净收益的提高率取决于耕地流转费用,临界点为14695元/hm²;相比non-IPBS,IPBS生产1tFPCM的温室气体排放、能源消耗、水消耗、土地占用分别减少6%、6%、5%、7%,如果青贮玉米自给率提升到100%,则相应减少16%、16%、11%、14%.IPBS在降低青贮玉米种植的化肥施用、解决养殖场粪便污染等方面优势明显,在提升养殖经济效益、降低温室气体排放等方面具有巨大潜力,值得推广.     

A Multi-Criteria Analysis of Sustainability Effects of Increasing Concentrate Intensity in Swedish Milk Production 1989–1999

The concept of sustainable development is forcing standard economic analysis to acknowledge and address the existence of dimensions of performance, which are not reducible to monetary accounting. In particular, the implementation of this concept in practice requires: (a) the simultaneous handling of indicators developed in different disciplinary fields; and (b) an approach more related to the procedures adopted by consultants (Participatory Integrated Analysis), rather than theoretical academic analysis looking for ‘the’ optimal solution. The case study considered in this paper is a multi-criteria analysis of changes, which occurred in the Swedish milk production sector for the period 1989–1999. Multi-criteria impact matrices and multi-criteria representations are used to provide a transparent method of integrated analysis. Changes are characterized and quantified in a way that makes it possible to relate the impact of existing trends in relation to different sub-objectives (variation in performance in relation to social, economic and ecological indicators). The results of this analysis confirm a few well known predicaments of sustainability associated with agriculture. The growth of Sweden economy is driving a major increase in material throughputs within its agricultural sector. The need of increasing agricultural throughput (especially labour productivity) has moved the Swedish dairy sector in a clear situation of decreasing marginal return ( = large increases in inputs are not reflected in a proportional increase in output). Therefore, sound policies of development of this sector aimed at increasing the goal of sustainability have to be developed by considering several indicators of performance, and not only economic variables.     

Production of monoclonal antibody against doxycycline for immunoassay of seven tetracyclines in bovine muscle and milk

The objective of this study was to produce a generic monoclonal antibody for multi-determination of the residues of tetracycline drugs in bovine muscle and milk. Two new immunogens of doxycycline were prepared that were used to produce the monoclonal antibodies. Results showed the obtained antibodies simultaneously recognized seven tetracycline drugs (doxycycline, tetracycline, chlortetracycline, oxytetracycline, minocycline, methacycline, demeclocycline). The obtained antibodies and three coating antigens were arranged into six combinations to optimize the reagents combination. After comparison of the performances of these combinations, a heterologous indirect competitive ELISA was then used to determine the seven tetracyclines in bovine muscle and milk. The crossreactivities to the seven analytes were in the range of 47%–102% and the limits of detection were in the range of 1.5–6.9 ng/mL depending on the compound. The recoveries of the seven drugs from fortified blank samples were in the range of 75.3%–106.8% with coefficients of variation lower than 10.9%. Therefore, this method could be used as a multi-analytes screen tool for routine monitoring of the residues of these tetracycline drugs in bovine muscle and milk.     

Direct electrochemical detection of glyphosate at carbon paste electrode and its determination in samples of milk,orange juice,and agricultural formulation

Abstract

This paper describes a simple, inexpensive, highly sensitive, selective, and efficient electrochemical method to determine glyphosate (GLY) in samples of milk, orange juice, and agricultural formulation. The oxidation reaction on the electrode surface was electrochemically characterised by cyclic voltammetry (CV) and square wave voltammetry (SWV). The investigation of GLY at carbon paste electrode revealed a non-reversible oxidation peak at +0.95 V versus Ag/AgCl, which was used for electrochemical detection of GLY. The operating parameters (pH, frequency, step potential, and amplitude) were optimised in relation to the peak current intensity, and a calibration curve was set up in a concentration range of 4.40?×?10^?8–2.80?×?10^?6 mol L^?1, with a detection limit of 2?×?10^?9 mol L^?1. After calibration curve was plotted, the developed procedure was applied to determine GLY in previously contaminated samples: milk and orange juice, and in a commercial formulation, obtaining recovery values between 98.31% and 103.75%. These results show that the proposed method can be used for GLY quantification in different samples with high sensitivity, specificity, stability, and reproducibility.