Development of Analytical Methods of Multi-pesticide Residues for Controlling the Tea Quality, from Tea Plantation to Consumer
Development of Analytical Methods of Multi-pesticide Residues for Controlling the Tea Quality, from Tea Plantation to Consumer

Author: Tuan Kiet Ly

Publisher:

Published: 2020

Total Pages: 0

ISBN-13:

DOWNLOAD EBOOK

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.

Analysis of Pesticide in Tea
Analysis of Pesticide in Tea

Author: Guo-Fang Pang

Publisher: Elsevier

Published: 2018-08-18

Total Pages: 952

ISBN-13: 0128127287

DOWNLOAD EBOOK

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

Multiresidue Methods for the Analysis of Pesticide Residues in Food
Multiresidue Methods for the Analysis of Pesticide Residues in Food

Author: Horacio Heinzen

Publisher: CRC Press

Published: 2017-10-10

Total Pages: 531

ISBN-13: 1351644637

DOWNLOAD EBOOK

In the last decades the public concern on the pesticide residues content in foods have been steadily rising. The global development of food trade implies that aliments from everywhere in the world can reach the consumer`s table. Therefore, the identification of agricultural practices that employ different pesticides combinations and application rates to protect produce must be characterized, as they left residues that could be noxious to human health. However, the possible number of pesticides (and its metabolites of toxicological relevance) to be found in a specific commodity is almost 1500, and the time needed to analyze them one by one, makes this analytical strategy a unrealistic task. To overcome this problem, the concept of Multi Residue Methods (MRM) for the analysis of pesticide traces have been developed. The advent of new and highly sensitive instrumentation, based in hyphenatedchromatographic systems to coupled mass analyzers (XC (MS/MS) or MSn) permitted simultaneously the identification and the determination of up to hundreds of pesticide residues in a single chromatographic run. Multiresidue Methods for the Analysis of Pesticide Residues in Food presents the analytical procedures developed in the literature, as well as those currently employed in the most advanced laboratories that perform routinely Pesticide Residue Analysis in foods. In addition to these points, the regulations, guidelines and recommendations from the most important regulatory agencies of the world on the topic will be commented and contrasted.

Determination of Multiple Pesticides Residues in Imported Tea in UAE Using Liquid and Gas Chromatography and Tandem Mass Spectrometry
Determination of Multiple Pesticides Residues in Imported Tea in UAE Using Liquid and Gas Chromatography and Tandem Mass Spectrometry

Author: Sarra Ali Mohammed Hassan Mulla

Publisher:

Published: 2016

Total Pages: 350

ISBN-13:

DOWNLOAD EBOOK

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).

Principles, Methods, and General Applications
Principles, Methods, and General Applications

Author: Gunter Zweig

Publisher: Elsevier

Published: 2013-09-11

Total Pages: 652

ISBN-13: 1483220818

DOWNLOAD EBOOK

Analytical Methods for Pesticides, Plant Growth Regulators, and Food Additives, Volume 1: Principles, Methods, and General Applications provides information on analytical techniques useful for the determination of pesticides, plant growth regulators, and food additives. The book discusses the potential hazard of minute residues to human and animal health; the principles of formulation and residue analyses; and the principles of food additive analysis. The text also describes the extraction and clean-up procedures; and the principles of toxicological testing methods. The methods for pesticide analysis in meat products; and the formulation and residue analysis in government laboratories are also considered. The book further tackles other methods, such as spectrophotometric methods, chromatography, isotope methods, enzymatic methods; and bioassay. Agricultural toxicologists and people studying pesticides and food additives will find the text invaluable.

Pesticide Residues in Foods
Pesticide Residues in Foods

Author: W. George Fong

Publisher: John Wiley & Sons

Published: 1999-01-29

Total Pages: 389

ISBN-13: 0471574007

DOWNLOAD EBOOK

Advances in analytical chemistry methodology now allow us to detect the most minute trace amounts of pesticides. As this capacity grows, so does public concern about toxic contamination, resulting in stricter government regulations and a growing demand for even more sensitive, precise, and reliable analysis. Addressing the interplay between regulations and the development of analytical technology, this volume presents the first unified treatment of the regulatory and analytical aspects of pesticide residues. Current regulations, existing and emerging methodologies, state-of-the-art instrumentation, and the basic science of analyzing for pesticides in food and other environmental media are all covered. The book provides step-by-step guidelines to analytical techniques, along with real-world examples from the latest research-showing the reader how to analyze minute traces of pesticides quickly and accurately, using both highly sophisticated and basic, less sensitive techniques. Many safety issues are explored in depth, as are the regulatory aspects of pesticide registration, residue analysis, exposure monitoring, risk assessment, and tolerance enforcement. Timely, authoritative, and practical throughout, Pesticide Residues in Foods is an invaluable reference for analytical chemists and laboratory managers everywhere-in industry, agriculture, environmental sciences, research, and instrument manufacturing-and for anyone with an interest in the broader environmental, agricultural, and consumer-related implications of pesticide use. An invaluable resource for analytical chemists and laboratory managers, Pesticide Residues in Foods provides a complete overview of the theory, practice, and regulatory aspects of pesticide residue analysis today, including: * All regulatory issues, from risk assessment and tolerance to data-quality requirements to laboratory accreditation standards * State-of-the-art methodologies and instrumentation, including high- performance liquid chromatography and mass spectrometry * The application of analytical technology to "green chemistry," such as the reduction of solvents and toxic reagents in the laboratory * Novel solutions to the old problem of keeping the food supply safe from harmful levels of pesticides * Ample examples to help analytical chemists select the most appropriate method for a given residue analysis * Easy-to-use tables and figures throughout the text

Integrated Analytical Approaches for Pesticide Management
Integrated Analytical Approaches for Pesticide Management

Author: Britt Maestroni

Publisher: Academic Press

Published: 2018-07-17

Total Pages: 340

ISBN-13: 0128161566

DOWNLOAD EBOOK

Integrated Analytical Approaches for Pesticide Management provides proven laboratory practices/examples and methods necessary to control pesticides in food and water in various environments. The book presents insights into good laboratory practices and examples of methods used in individual specialist laboratories, thus enabling stakeholders in the agri-food industry to appreciate the importance of proven, reliable data and the associated quality assurance approaches for end product testing for toxic levels of contaminant residues in food. The book is written in a rigorous, but simple, way to make sure that a broad range of readers can appreciate its technical content. The book's practical nature and generic guidelines distinguish it from others in the marketplace. Provides coverage of risk assessment and effective testing technologies Covers generic guidelines on pesticide analysis on different environmental matrices for use in the developed and developing world Presents the most up-to-date information in research sample testing preparation and method validation to detect pesticide residues in food Includes examples of each method for practical application Demonstrates proven, reliable research data and the associated quality assurance approaches for end product testing for food, water and soil sediment Describes the concept of integrated analytical approaches for pesticide management practices