Analysis of Pesticide in Tea: Chromatography-Mass Spectrometry Methodology is a comprehensive book, providing serial, rapid, high-throughput analytical methods for determining more than 600 pesticides in tea. There are increasing numbers of strict limit standards for pesticide residues in edible agricultural products in countries all over the world. The threshold for pesticide residues in tea is high for international trade. At present, 17 countries and international organizations have stipulated MRL levels for over 800 pesticide residues in tea. All methods described in this book are validated by an independent, U.S.-based organization (AOAC International), and all indexes have satisfied AOAC International's criteria. China has a history of 5000 years in growing tea and is a large tea producer with 80 million people involved in tea growing. China exports tea to over 100 countries worldwide, enjoying a high reputation for quality and variety. Covers a wide range of research activities that are highly appropriate to current research methods Reflects the most recent research in nearly all cases, providing an excellent compilation of feasible methods needed for official analysis Describes methods that are internationally validated by an independent, U.S.-based organization (AOAC International) Authored by Dr. Pang, who is internationally recognized in the area of pesticide residues and other contaminants in foods
An accurate, rapid and reliable method for the simultaneous determination of 48 pesticide residues in United Arab Emirates imported tea (Green and Black) by liquid and gas chromatography coupled with tandem mass spectrometry LC-ESI (+) - MS/MS and GC-EI-MS/MS. Multiple reaction monitoring (MRM) mode was used in which two transitions for each compound for pesticide identification and quantification in the presence of internal standards. Modified quick, easy, cheap, effective, rugged, safe (QuEChERS) method was used for sample clean up and preparation for chromatographic analysis. The performance of the newly developed analytical method was validated in accordance with EU SANCO guidelines (SANCO/12571/2013) for monitoring pesticide multi-residues by evaluating method linearity, recoveries, precision (reproducibility and repeatability), sensitivity (limits of detection (LODs) and limits of quantification (LOQs)) for each one of the tested pesticides. LC-MS/MS was used to detect and quantitate 38 pesticides residues. For Black tea, 70% of tested pesticides spiked at levels of 10 and 100 ng.mL-1, the mean recoveries were 99.83% and 94.27%, and average RSD were 14.38% and 13.4 %, respectively. For Green tea, 80% of the tested pesticides spiked at levels of 10 and 100 ng mL-1, the mean recoveries were 93.75% and 95.08, and average RSD was 11.10% and 13.14%, respectively. GCMSMS, used to detect 10 pesticides residues. For Black tea, 70% of tested pesticides spiked at levels of 10 and 100 ng mL-1, the mean recoveries were 85.35% and 78.47%, and average RSD were 10.50% and 8.60%, respectively. For Green tea, 80% of the tested pesticides spiked at levels of 10 and 100 ng mL-1, the mean recoveries were 79.29% and 73.35%, and average RSD were 7.46% and 5.94%, respectively. The limits of detection for all targeted pesticides lower than the respective MRL established by codex and the EU legislations. Real tea samples of different types and brands were collected from UAE local markets during the time period of 2014-2015and were analyzed in five replicates for each brand. Three green tea brands and five black tea brands in addition to two slimming tea brands were investigated using the validated analytical method. Buprofezin and Acetamiprid pesticides were found in green tea samples but at lower concentration levels, below the Maximum Residue Levels (MRL) values set by the CODEX and EU. Also, Difenoconazole found in slimming tea at lower concentration levels, below the Maximum Residue Levels (MRL).
Tea is the second most-consumed beverage in the world, surpassed only by water, due to its health benefits. However, because of monoculture cultivation practices, the use of pesticides during tea cultivation is common. Over time, the number of pesticides used has increased, and, to protect consumers' health, many countries and regions have established maximum residue limits of pesticides for a variety of foods and beverages, including tea. For instance, the European Union (EU) has set the maximum residue limits (MRLs) for more than 480 pesticides and their metabolites in tea products. Therefore, the development of analytical methods for multi-pesticide residues in tea is a challenge, because tea is a complex commodity with many compounds that can interfere with results, such as polyphenols, pigments, and caffeine. The aim of this thesis is to develop rugged and robust methods with high sensitivity, accuracy, and precision to meet the EU regulations for simultaneous determination of 400 pesticide residues in tea products using ultra performance liquid and gas chromatographies coupled to tandem mass spectroscopy (UPLCMS/ MS and GC-MS/MS, respectively). The first part of thesis focused on elimination of matrix effects in green tealeaves by combining QuEChERS (quick, easy, cheap, effective, rugged, and safe) extraction and mixed-mode SPE (solid phase extraction) clean-up. A C18 SPE cartridge paired with SPE GCB/PSA proved to be the most effective clean-up method and enabled 225 pesticide residues to be quantified, based on solvent calibration curves (154 residues using UPLCMS/ MS and 71 residues using GC-MS/MS). The analytical methods were validated fully in accordance with the SANTE/11945/2015 (EU). LOQs for most pesticides (386/400 or 96.5%) were below 10 μg/kg, i.e., less than the EU MRL (5-70 mg/kg). In the second part, matrix effects for 400 pesticide residues were investigated and improved for the analysis of different types of teas (white, green, oolong and black ones). Results showed that combining QuEChERS extraction and mixed-mode SPE clean-up, and following the reduction of the injection volume were found to be the most effective procedure to overcome matrix effects. More than 190 pesticides (> 95% of the 200 ones) had the matrix effect within the range of ± 20% for UPLC-MS/MS. Therefore, they can be quantified using solvent calibration curves. On the other hand, matrix-matched calibration curves should be used to overcome matrix effects for GC-MS/MS. Moreover, we recognized that matrix effects in GC-MS/MS were not only signal enhancement but also suppression. Finally, in the third part of this work, the established method was successfully applied to the determination of multi-pesticide residues in 106 tea samples. In total, 26 tea samples (24.5%) were containing at least one pesticide violation, with 43 pesticide residue violations. The most frequently detected pesticides were neonicotinoids, synthetic pyrethroids, and triazole fungicides. In terms of origin in this study, Taiwan had the most pesticide-contaminated samples with 83.3%, following by China (73.7%), Vietnam (64.7%), and India (Darjeeling) (55.0%). The results showed that samples exceeding EU MRLs regulations were still high with 24.5%. Therefore, assessments of multipesticide residues in tea need to be continued.
Pesticide-clay-water interactions; Pesticide organic matter interactions; Movement of pesticides in soil; Movement of pesticides in surface water; Volatilization of pesticides; nonbiological degradation of pesticides; Degradation of pesticides by soil microorganisms; Persistence of pesticides in soil; Effects of soil on the biological activity of pesticides; Plant uptake of insecticides, fungicides, and fumigants from soils; Effects of pesticides on microorganisms in soil and water; Effects of pesticides on nontarget invertebrates in freshwater and soil; Prevention and detoxification of pesticide residues in soil; Removal of organic pesticides from water to improve quality; Extraction and analytical techniques for pesticides in soil, sediment, and water.
Human activities have dramatically changed the composition and organisation of soils. Industrial and urban wastes, agricultural application and also mining activities resulted in an increased concentration of heavy metals in soils. How plants and soil microorganisms cope with this situation and the sophisticated techniques developed for survival in contaminated soils is discussed in this volume. The topics presented include: the general role of heavy metals in biological soil systems; the relation of inorganic and organic pollutions; heavy metal, salt tolerance and combined effects with salinity; effects on abuscular mycorrhizal and on saprophytic soil fungi; heavy metal resistance by streptomycetes; trace element determination of environmental samples; the use of microbiological communities as indicators; phytostabilization of lead polluted sites by native plants; effects of soil earthworms on removal of heavy metals and the remediation of heavy metal contaminated tropical land.
The Codex Alimentarius (Latin, meaning Food Law or Code) is a collection of internationally adopted food standards. Food labeling is the primary means of communication between the producer and seller of food on one hand, and the purchaser and consumer of the other. These guidelines have been prepared for the purpose of providing an agreed approach to the requirements which underpin production of, and the labeling and claims for, organically produced foods.
This handbook provides a systematic description of the principles, procedures, and technology of the modern analytical techniques used in the detection, extraction, clean up, and determination of pesticide residues present in the environment. This book provides the historical background of pesticides and emerging trends in pesticide regulation. The
