scholarly journals Simultaneous Determination of Rimsulfuron and Haloxyfop-P-methyl and Its Metabolite Haloxyfop in Tobacco Leaf by LC-MS/MS

2019 ◽  
Vol 102 (5) ◽  
pp. 1632-1640
Author(s):  
Yurong Yu ◽  
Shan Zhao ◽  
Ya Yang ◽  
Ya Chen ◽  
Daimei Qiu ◽  
...  

Abstract Background: Tobacco (Nicotiana tabacum L.), is an important economic crop. In China, the use of rimsulfuron and haloxyfop-P-methyl herbicides for weed management during the planting period is necessary to improve the production of tobacco. Objective: To establish and validate a quick, easy, cheap, effective, rugged, and safe LC-MS/MS method to determine rimsulfuron, haloxyfop-P-methyl, and haloxyfop in tobacco leaf samples. Methods: We optimized MS/MS conditions and chromatographic conditions for optimal detection conditions. The extraction solvent and sorbent were optimized, and the analysis of variance was applied to analyze the pretreatment method to obtain the optimal pretreatment conditions. Results: The validation results showed that the proposed method exhibited good linearity (R2 > 0.9978), satisfactory recovery (72.51–101.60%) and low LOQ (0.02–1.00 mg/kg). The matrix effects of the three analytes in the two tobacco leaf matrixes were different. The dissipation results showed that the half-lives of rimsulfuron and haloxyfop-P-methyl in fresh tobacco leaf samples were ranged from 2.4 to 3.7 days. The final residues of rimsulfuron, haloxyfop-P-methyl, and haloxyfop in flue-cured tobacco leaf samples were all lower than the LOQ. Conclusions: The results demonstrate that the developed method could be used to detect rimsulfuron, haloxyfop-P-methyl, and haloxyfop in tobacco leaf matrixes. Highlights: A method for simultaneous determination of rimsulfuron, haloxyfop-P-methyl, and haloxyfop in tobacco leaf samples with high sensitivity has been established for the first time.

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Lianguo Chen ◽  
Jianshe Ma ◽  
Xianqin Wang ◽  
Meiling Zhang

A specific ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method has been developed for the simultaneous determination of six Uncaria alkaloids in mouse blood with midazolam as the internal standard (IS). Only 20 μL blood was needed for sample preparation, and the protein was precipitated with acetonitrile. The UPLC BEH C18 column (2.1 mm×100 mm, 1.7 μm) was used for chromatographic separation. The mobile phase consisted of 0.1% formic acid and acetonitrile with gradient elution within 5.5 min. Multiple reaction monitoring (MRM) and the positive electrospray ionization model were used for quantitative analysis. The accuracy of the UPLC-MS/MS method ranged from 86.5% to 110.4%. The precision for intraday and interday was ≤15% each. The mean recovery and the matrix effects were found to be 64.4-86.8% and 94.1-109.4%, respectively. The calibration curves in blood were linear in the range of 1-1000 ng/mL with a favorable correlation coefficient (r2) of 0.995. The pharmacokinetic results showed that six Uncaria alkaloids metabolized rapidly in mice with a half-life between 0.6 h and 4.4 h. The bioavailability of corynoxeine, isocorynoxeine, rhynchophylline, isorhynchophylline, hirsutine, and hirsuteine was 27.3%, 32.7%, 49.4%, 29.5%, 68.9%, and 51.0%, respectively, which showed satisfactory oral absorption of each alkaloid.


2022 ◽  
Vol 10 (1) ◽  
pp. 93
Author(s):  
Yuhua Gao ◽  
Xiaoyuan Wang ◽  
Xianwen Fang ◽  
Xuebo Yin ◽  
Lu Chen ◽  
...  

Fluorine and chlorine are important tracers for geochemical and environmental studies. In this study, a rapid alkaline digestion (NaOH) method for the simultaneous determination of fluorine and chlorine in marine and stream sediment reference samples using ion chromatography is developed. The proposed method suppresses the volatilization loss of fluorine and chlorine and decreases the matrix effects. The results are in good agreement with fluorine ~100%, chlorine ranging from 90 to 95% of the expected concentrations. The detection limits of this method were 0.05 μg/g for fluorine and 0.10 μg/g for chlorine. This method is simple, economical, precise and accurate, which shows great potential for the rapid simultaneous determination of fluorine and chlorine in large batches of geological and environmental samples commonly analyzed for environmental geochemistry studies.


2021 ◽  
Vol 11 (22) ◽  
pp. 10931
Author(s):  
Natasa P. Kalogiouri ◽  
Emmanouil-Nikolaos Papadakis ◽  
Maria G. Maggalou ◽  
George S. Karaoglanidis ◽  
Victoria F. Samanidou ◽  
...  

The possible presence of contaminants, pesticide residues and mycotoxins, in agricultural commodities is a critical issue for food safety, causing great concern. In this work, a simple and rapid analytical method employing liquid chromatography–tandem mass spectrometry (LC-MS/MS) was developed for the simultaneous determination of pesticide residues and mycotoxins in apples. Microwave-assisted extraction (MAE) was used for sample preparation. The MAE protocol was optimized after evaluating the effects of the following extraction parameters: (a) extraction solvent, (b) acidic environment, (c) temperature, and (d) extraction time. The multiresidue MAE-LC-MS/MS method was validated for linearity, accuracy (bias and precision), limits of detection (LODs), limits of quantification (LOQs), and matrix effect. The validation of the method was carried out according to the SANTE/12682/2019 document. The method demonstrated good linearity with R2 ≥ 0.99, acceptable accuracy in the recovery rate range 70–116%, acceptable interassay precision with RSD% ≤ 20, and low LODs and LOQs in the ranges 0.005–0.015 μg/g and 0.01–0.03 μg/g, respectively. Matrix effects were observed only for the 25% of the analytes. The performance of the MAE-LC-MS/MS method was compared to that of the QuEChERS sample preparation method, and the MAE-LC-MS/MS method proved to be rapid and effective.


Author(s):  
Zheng Yu ◽  
Fan Chen ◽  
Yinan Jin ◽  
Minyue Zhou ◽  
Xianqin Wang ◽  
...  

Abstract In this study, a UPLC-MS/MS method was developed to measure the concentrations of the flavonoids oroxin A, oroxin B, oroxylin A, oroxyloside, chrysin, chrysin 7-O-beta-gentiobioside, and guaijaverin in the blank mouse blood, and the method was then used in the measurement of the pharmacokinetics of the compounds in mice. Oroxin A, oroxin B, oroxylin A, oroxyloside, chrysin, chrysin 7-O-beta-gentiobioside, and guaijaverin were administered intravenously at a dose of 5 mg kg−1, and the mouse blood (20 μL) was withdrawn from the caudal vein 0.08333, 0.25, 0.5, 1, 2, 4, 6, 8, and 10 h after administration. The mobile phase used for chromatographic separation by gradient elution was composed of acetonitrile and water (0.1% formic acid). The analytes were detected by operating in electrospray ionization (ESI) positive-ion mode using multiple reactions monitoring (MRM). The intra-day and inter-day accuracy ranged from 86.2 to 109.3%, the intra-day precision was less than 14%, and the inter-day precision was less than 15%. The matrix effect ranged from 85.3 to 111.3%, and the recovery of the analytes after protein precipitation were all above 78.2%. This method had the advantages of high sensitivity, accuracy, and recovery, and it had excellent selectivity, which enabled it to be applied to measuring the pharmacokinetics of the analytes in mice.


Author(s):  
Beena Sunilkumar ◽  
S. B. Singh

A simple method has been developed for the determination of trace toxic elements like arsenic, lead and chromium in titanium dioxide pigment samples by ICP OES attached with a Concomitant Metals Analyser. Open mineral acid decomposition was used for sample dissolution employing a mixture of nitric and hydrofluoric acids. The continuous online generation of hydrides into the plasma was achieved through a concomitant metals analyser. The recovery of arsenic, lead and chromium and the matrix effects of titanium on these elements have been studied with spiking experiments. The proposed method has been successfully applied to the determination of arsenic and other elements in titanium pigment samples. The continuous hydride generating system, Concomitant Metals Analyser (CMA) improved the sensitivity of analysis nearly five times in pigment samples. The precision of the measurements was found to be less than 10% RSD.


2021 ◽  
Author(s):  
Tao Lin ◽  
Xinglian Chen ◽  
Li Wang ◽  
Haixian Fang ◽  
Maoxuan Li ◽  
...  

Abstract The simultaneous determination method of 8 amide pesticides by multi-walled carbon nanotubes (MWCNs) cleanup, combined with QuEChERS method and ultra-high performance liquid chromatography-triple quadrupole tandem mass spectrometry has been developed and successfully applied in complex matrix such as green onions, celery, leeks, citrus, lychees, avocado. The matric effect of MWCNs is optimized and compared with QuEChERS materials. The results show that MWCNs can effectively reduce the matrix effect in sample extraction. The mass spectrometry is optimized, through their chemical structure skeletons, the ESI+ and ESI- mode are simultaneously scanned in the method. The coefficient (r) is greater than 0.9990, the limit of quantification ranges from 0.03 to 0.80 μg/kg, the recovery rate ranges from 71.2% to 120%, and the relative standard deviation (RSD) ranges from 3.8% to 9.4%. The method is fast, simple, sensitive, and has good purification effect. It is suitable for the rapid determination of amide pesticides in complex matrix agri-food.


1963 ◽  
Vol 7 ◽  
pp. 542-554
Author(s):  
Frank L. Chan

AbstractRecently, interest in the determination of selenium in trace amounts has been greatly intensified because of the nutritional aspects of this element. It has been reported that selenium in the amount of 13 μg in the form of sodium selenite in 100 g of feed has an effect similar to that of vitamin E. In the field of semiconductors, the detection and determination of trace amounts of selenium in arsenic, antimony, and small single crystals of solid solution of cadmium selenide and sulfide are of considerable importance in semiconductor performance.In the Aerospace Research Laboratories, 4,5 diamino-6-tbiopyi-imidine has been successfully adopted as a reagent for the spectrophotometric determination of selenium. The reaction of 4,5 diamino-6-thiopyrimidine and tetxavalent selenium produces a yellow color with the formation of elemental selenium. It is possible to determine elemental selenium by collecting it in a thin layer. The selenium deposited in this layer may then be determined by an X-ray fluorescence method. A procedure of this nature has the advantage of eliminating the matrix effects commonly encountered in X-ray fluorescence. Furthermore, the slow generation of selenium affords a convenient means of detection and confirmation of this element by the use of X-ray diffraction procedures. By this technique selenium is first converted to its tetravalent state and is then reacted with 4,5 diamino-6-thiopyrimidine. On standing, the selenium is reduced to a red precipitate of elemental selenium which can be dissolved in carbon disulfide. Finally, the selenium can be converted into its hexagonal structure by annealing at 205-207°C.


2010 ◽  
Vol 93 (5) ◽  
pp. 1503-1514 ◽  
Author(s):  
Sumita Dixit ◽  
Subhash K Khanna ◽  
Mukul Das

Abstract A simple and sensitive HPLC method has been developed for the simultaneous determination of eight permitted food colors and five commonly encountered nonpermitted colors in various food commodities, including sugar-, fat-, and starch-based food matrixes. The method uses a specific food category-based cleanup/treatment procedure before color extraction to avoid the interference of food matrixes, and to obtain the optimal color extraction. Analysis was performed on a reversed-phase C18 -Bondapak column with ammonium acetate and acetonitrile gradient elution as the mobile phase; a programmable max-specific visible detection was used to monitor colors to obtain the higher sensitivity and expanded scope needed for multicolor blends having diverse absorption maxima. All colors showed good linearity, with regression coefficients of 0.99740.9999. The LOD and LOQ values ranged from 0.01 to 0.12 mg/L, and from 0.04 to 0.83 mg/L or mg/kg, respectively. The intraday and interday precision tests produced good RSD values, and the recoveries from different food matrixes ranged from 82 to 104%. The method offers high sensitivity for analysis of a wide variety of food matrixes containing a broad scope of multicolor blends. Two nonpermitted colors, orange II and metanil yellow, were found. Also, a number of samples contained permitted colors at levels two-to seven-fold higher than those prescribed.


Author(s):  
Jing Zhou ◽  
Hongzhe Wang ◽  
Caiyun Miao ◽  
Yunxi Yao ◽  
Jianshe Ma

AbstractA rapid and simple UPLC-MS/MS method was developed to determine toddalolactone in mouse blood and applied to measure the pharmacokinetics of toddalolactone in mice. Blood samples were first preprocessed by ethyl acetate liquid-liquid extraction. Oxypeucedanin hydrate (internal standard, IS) and toddalolactone were gradient eluted from a UPLC BEH C18 column using a mobile phase consisting of acetonitrile and water (0.1% formic acid). Using electrospray ionization (ESI) as the ionization source, multiple reaction monitoring was used to detect the precursor and product ions of m/z 309.2 and 205.2, respectively, for toddalolactone and of m/z 305.1 and 203.0 for IS, respectively, for quantitative detection. A calibration curve was run over the concentration range of 5–4,000 ng/mL (r > 0.995). The matrix effects ranged from 93.5 to 98.4%, and the recovery was higher than 77.3%. The precision was less than 13%, and the accuracy ranged from 90.9 to 108.4%. The developed UPLC-MS/MS method was successfully used for measuring the pharmacokinetics of toddalolactone in mice after oral (20 mg/kg) and intravenous administration (5 mg/kg), and the absolute bioavailability of toddalolactone was 22.4%.


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