Meng Wenting

Bio: Meng Wenting is an academic researcher. The author has contributed to research in topics: Quechers & Pesticide residue. The author has an hindex of 5, co-authored 9 publications receiving 95 citations.

Method for detecting 153 pesticide residues in heart benefiting and pulse restoring particle

Abstract: The invention relates to a method for detecting 153 pesticide residues in a heart benefiting and pulse restoring particle. The method is a liquid chromatography-mass spectrometry method. The method comprises the following steps: preparing a sample solution, preparing a matrix mixed reference substance working solution, and detecting the solutions through using the high performance liquid chromatography-mass spectrometry, wherein the sample solution is prepared through the following steps: crushing the heart benefiting and pulse restoring particle, weighing 1.8-2.2 g of the heart benefiting and pulse restoring particle, adding 80-120 [mu]L of an internal standard solution with the concentration of 5 [mu]g/mL, adding 8-12 mL of water, infiltrating the particle for 28-32 min, adding 8-12 mL of an acetonitrile solution containing 0.08-0.12% of acetic acid, oscillating the obtained solution in a swirl mixing oscillator at a rate of 4000-6000 r/min for 1.8-2.2 min, adding 3-5 g of anhydrous magnesium sulfate and 0.08-1.2 g of sodium acetate, carrying out swirl shaking for 4-6 min, centrifuging the obtained solution at a speed of 4000-6000 r/min for 4-6 min, taking 0.8-1.2 mL of the obtained supernatant, adding the supernatant to a centrifuging tube which is filled with 140-460 mg of anhydrous sodium sulfate, 23-27 mg of PSA, 48-52 mg of C18 and 2.3-2.7 mg of GCB in advance, carrying out swirl shaking for 2-4 min, centrifuging the obtained solution at a rate of 4000-6000 r/min for 4-6 min, taking the obtained supernatant, and filtering the supernatant by a 0.2-0.24 [mu]m filter membrane.

Determination method for heavy metal content in mineral water

Abstract: The invention relates to a determination method for the heavy metal content in mineral water, wherein the determination method is an inductively coupled plasma mass spectrometry (ICP-MS) method, and the detected heavy metals comprise Be, B, Cr, Mn, Ni, Cu, As, Mo, Ag, Cd, Sb, Ba, Hg and Pb. The determination method comprises: (1) sample solution preparation; (2) standard solution preparation; (3) internal standard solution preparation; and (4) content determination: injecting the internal standard solution, the standard solution and the sample solution according to ICP-MS working conditions, and detecting the contents of each element.

A review of extraction, analytical and advanced methods for determination of pesticides in environment and foodstuffs

Abstract: Pesticides are widely applied to prevent unwanted pests from attacking crops and livestock which led to their access into the environment. Overuses of pesticides in environment are presence of pesticide residues and their metabolites that are causing serious detrimental effects on human health and all other living organisms. Several severe diseases (Cancer, chronic obstructive pulmonary disease, birth defects, infertility) and more damages of human health are associated with the exposure of pesticides. The maximum residue limits for pesticides have been regulated by the Codex Alimentarius Commission and European Union to protect human health. Thus, monitoring these compounds is extremely important to ensure that only permitted levels of pesticide are consumed. To date, several techniques have been developed for pesticide detection, from conventional analytical to advanced detection techniques. The conventional analytical methods are gas chromatography and high performance liquid chromatography coupled with various detectors involved a sample preparation step prior to further analysis. Advanced detection methods refer to the sensors development such as electrochemical, optical, piezoelectric and molecular imprinted polymer. In this review, we summarized and explained the available analytical and advanced methods for determination of pesticides compound in environment and foodstuffs. Also, pesticides classification and its toxicity, and available extraction methods are briefly discussed.

A Review of Current Methods for Analysis of Mycotoxins in Herbal Medicines.

Abstract: The presence of mycotoxins in herbal medicines is an established problem throughout the entire world. The sensitive and accurate analysis of mycotoxin in complicated matrices (e.g., herbs) typically involves challenging sample pretreatment procedures and an efficient detection instrument. However, although numerous reviews have been published regarding the occurrence of mycotoxins in herbal medicines, few of them provided a detailed summary of related analytical methods for mycotoxin determination. This review focuses on analytical techniques including sampling, extraction, cleanup, and detection for mycotoxin determination in herbal medicines established within the past ten years. Dedicated sections of this article address the significant developments in sample preparation, and highlight the importance of this procedure in the analytical technology. This review also summarizes conventional chromatographic techniques for mycotoxin qualification or quantitation, as well as recent studies regarding the development and application of screening assays such as enzyme-linked immunosorbent assays, lateral flow immunoassays, aptamer-based lateral flow assays, and cytometric bead arrays. The present work provides a good insight regarding the advanced research that has been done and closes with an indication of future demand for the emerging technologies.

Current trends in QuEChERS method. A versatile procedure for food, environmental and biological analysis

Abstract: QuEChERS (quick, easy, cheap, effective, rugged, and safe) method was initially developed by Anastassiades and coworkers as an interesting alternative based on the main principles of the Green Chemistry to the determination of pesticides in fruits and vegetables. However, the great versatility of the procedure has allowed its application in other types of matrices and analytes with excellent results. In fact, nowadays the main advantages of QuEChERS such as the effective elimination of matrix effect as well as obtain a high recovery of target analytes are extensively known in diverse fields such as food, environmental and biological analysis. This review article pretends to provide an overview of the most relevant applications of the QuEChERS method in the last five years in these three different areas as well as the main trends regarding of the development and evolution of this sample preparation protocol.

Modification of Multiresidue QuEChERS Protocol to Minimize Matrix Effect and Improve Recoveries for Determination of Pesticide Residues in Dried Herbs Followed by GC-MS/MS

Abstract: An accurate, rapid, and reliable multiresidue QuEChERS method based on gas chromatography coupled with tandem mass spectrometry was developed for the determination of 235 pesticides in challenging, dry, complex herb matrices (Centaurea cyanus L, Matricaria chamomilla L, Thymus vulgaris L) Sample mass and the type of cleanup sorbent used to estimate the procedure’s effectiveness were optimized Purification steps with ChloroFiltr, ENVI-Carb, GCB, octadecyl, PSA, and Z-Sep as cleanup sorbents and a step without purification were compared To minimize the matrix effect and obtain acceptable recoveries for pesticides, 2 g of herb sample and 10 mL acetonitrile, followed by d-SPE cleanup step with a combination of 150 mg PSA/45 mg ENVI-Carb/900 mg MgSO4, and additionally 50 μL of 5% formic acid and some droplets of dodecane, were needed Matrix effects for the vast majority of pesticides were reduced (> 20%), showing suppression or enhancement Most recoveries were in the range of 70–120% (RSD < 18%), reaching the quantification limit of 0001 to 0002 mg kg−1 There was excellent linearity within the range from 0001 to 200 μg mL−1, and a correlation coefficient higher than 0999 was obtained Expanded measurement uncertainty was estimated to be between 4 and 43% Finally, the developed method was successfully employed to identify and quantify pesticide residues in the analysis of 46 real herb samples