Simultaneous Determination of Four Herbicide and Pesticide Residues in Chinese Green Tea Using QuEChERS Purification Procedure and UPLC-MS/MS Analysis

2013 ◽  
Vol 634-638 ◽  
pp. 1586-1590
Author(s):  
Su Fang Wang ◽  
Shou Jie Zhang ◽  
Chun Hong Dong ◽  
Guo Qing Wang ◽  
Jun Feng Guo ◽  
...  
Keyword(s):  
Formic Acid ◽  
Simultaneous Determination ◽  
Green Tea ◽  
Limit Of Detection ◽  
Multiple Reaction Monitoring ◽  
Graphitized Carbon Black ◽  
Ms Analysis ◽  
Relative Standard ◽  
Limit Of Quantitation

A method for simultaneous determination of residuals of four herbicides and pesticides, simazine, carboxin, diflubenzuron and rotenone, in Chinese green tea was developed. In the proposed method, the tea powder was placed in a centrifuge tube with a plug, extracted in saturated aqueous sodium chloride solution and acetonitrile, agitated using vortex oscillator, and then centrifuged 5 min at 4000 rpm. The supernatant solution was purified by primary secondary amine (PSA) sorbent, C18 power, and graphitized carbon black powder, respectively. Then the purified extracts were dissolved with acetonitrile:0.1% formic acid aqueous solution (40:60, V/V) and agitated, filtered using a syringe with 0.22 μm nylon filter prior to UPLC-MS/MS analysis. The UPLC analysis was performed on an ACQUITY UPLC® HSS T3 column (2.1 mm×100 mm, 1.8 µm), using acetonitrile-0.1% formic acid as mobile phase with the flow rate as 0.3 mL•min-1. Injection volume was 10 µL. Positive ionization mode was applied, and the ions were monitored in the multiple reaction monitoring (MRM) mode with curtain gas 0.069 MPa, collision gas 0.052 MPa, ESI ion spray voltage 5000 V, temperature 550 °C, nebulizer gas 0.24 MPa, and turbo gas 0.28 MPa. The limit of detection (LOD) and limit of quantitation (LOQ) of the proposed method are 1 μg•kg-1and 5 μg•kg-1, respectively. The average recoveries of the four pesticides at 10, 20, and 50 µg•kg-1spiking levels range from 77.4% to 95.3%. TheSupersSuperscript textcript textrelative standard deviation (RSD) (n=6) range form 11.83% to 4.52%.

Simultaneous Determination of Nitrofurazone, Nitrofurantoin, and Furazolidone in Channel Catfish (Ictalurus punctatus) Muscle Tissue by Liquid Chromatography

1994 ◽  
Vol 77 (2) ◽  
pp. 344-350 ◽  
Author(s):  
Heidi S Rupp ◽  
Robert K Munns ◽  
Austin R Long ◽  
Steven M Plakas
Keyword(s):  
Simultaneous Determination ◽  
Muscle Tissue ◽  
Ictalurus Punctatus ◽  
Channel Catfish ◽  
Mobile Phase ◽  
Limit Of Detection ◽  
Aqueous Acetic Acid ◽  
Relative Standard ◽  
Limit Of Quantitation

Abstract A liquid chromatographic (LC) method was developed for the simultaneous determination of nitro-furazone (NFZ), nitrofurantoin (NFT), and furazolidone (FZD) in catfish muscle tissue. The drugs were extracted from the tissue with acetonitrile, and the lipids were removed from the extract with hexane. The acetonitrile extract was evaporated by rotary evaporation, and the resultant drug residues were dissolved with LC mobile phase. The mixture was sonicated, centrifuged, and filtered. The drugs were determined by using LC with a Cie reversed-phase (ODS Hypersil) column, a mobile phase of acetonitrile–1 % aqueous acetic acid (25 + 75), and a photodiode array ultraviolet detector at 375 nm. NFZ, NFT, and FZD were each determined in catfish tissue at 5 fortification levels (80, 40, 20,10, and 5 ng drug/g tissue). Average recoveries of each of the 3 drugs at each level ranged from 70.7 to 101.5%, and relative standard deviations ranged from 2.2 to 18.6%. The limit of detection of each drug was approximately 1 ng drug/g tissue, and the limit of quantitation was 5 ng drug/g tissue. In the second part of the study, the method was used to determine nitrofuran residues incurred in catfish tissue. Live channel catfish were intravascularly dosed (10 mg/kg body wt) with NFZ to generate drug-incurred fish muscle tissue. Incurred NFZ levels exceeded 400 ng drug/g tissue at 2 h after dosing but decreased rapidly to approximately 1 ng drug/g tissue by 8 h after dosing, as determined by this method.

scholarly journals Simultaneous Determination of Methamphetamine and Its Isomer N-Isopropylbenzylamine in Forensic Samples by Using a Modified LC-ESI-MS/MS Method

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Yangxu Luo ◽  
Juan Du ◽  
Huadi Xiao ◽  
Ling Zheng ◽  
Xuncai Chen ◽  
...  
Keyword(s):  
Simultaneous Determination ◽  
Limit Of Detection ◽  
Multiple Reaction Monitoring ◽  
Acetate Solution ◽  
Accurate Identification ◽  
Esi Ms ◽  
Target Analytes ◽  
Relative Standard ◽  
Forensic Samples

Accurate identification and quantification of methamphetamine (MA) and its related substances are essential for the investigation and fair trial of drug offenses. In this study, a modified LC-ESI-MS/MS method for the simultaneous determination of MA and its isomer N-isopropylbenzylamine (N-IBA) in forensic samples was developed and validated. Optimum chromatographic separation of the target analytes was achieved on an Agilent Poroshell 120 SB-C18 column ( 4.6 × 100  mm, 2.7 μm) at 40°C with isocratic elution at the flow rate of 0.40 mL/min. The mobile phase was acetonitrile and 20 mM ammonium acetate solution containing 0.1% formic acid (80 : 20, v / v ). Positive ESI-MS/MS detection was performed in multiple reaction monitoring (MRM) mode to identify and quantify the target analytes. Method validation showed excellent linearity in the range of 0.51 ng/mL~51 ng/mL for MA and N-IBA. The low limit of detection (LLOD) and low limit of quantification (LLOQ) reached 0.1 ng/mL and 0.3 ng/mL for both analytes. The method showed a satisfactory accuracy with an inter- and intraday-relative error (RE) <20%, and a precision of inter- and intraday relative standard deviation (RSD) less than 15%. The validated method was successfully applied in real forensic samples and resulted in the detection of MA and N-IBA in 8 suspected samples in drug cases that only deemed MA positive using our previous routine screening procedure, which avoided the misidentification of N-IBA as MA.

scholarly journals A Validated HPLC-MS/MS Method for Simultaneous Determination of Militarine and Its Three Metabolites in Rat Plasma: Application to a Pharmacokinetic Study

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Hui-Yuan Sun ◽  
Lin Zheng ◽  
Zi-Peng Gong ◽  
Yue-Ting Li ◽  
Chang Yang ◽  
...  
Keyword(s):  
Formic Acid ◽  
Simultaneous Determination ◽  
Multiple Reaction Monitoring ◽  
Area Under The Curve ◽  
Internal Standard ◽  
Rat Plasma ◽  
Relative Standard ◽  
Method Accuracy

A rapid, reliable, and sensitive HPLC-electrospray ionization-tandem mass spectrometry (HPLC-MS/MS) method was established and validated for simultaneous determination of militarine and its three metabolites (gastrodin, α-isobutylmalic acid, and gymnoside I) in rat plasma. Plasma was acidified with formic acid, and protein was precipitated with methanol. MS/MS with ESI and multiple reaction monitoring at m/z 725.3→457.3, 457.1→127, 304.3→107.2, 189→129, and 417.1→267.1 was used for determination of militarine, gastrodin, α-isobutylmalic acid, gymnoside I, and puerarin (internal standard), respectively. Chromatographic separation was conducted using an ACE UltraCore SuperC18 (2.1 × 100 mm, 2.5 μm) column with gradient mobile phase (0.1% formic acid in water and acetonitrile). The lower limits of quantitation for militarine, gastrodin, α-isobutylmalic acid, and gymnoside I were 1.02, 2.96, 1.64, and 0.3 ng/mL, respectively. The relative standard deviations of intra- and interday measurements were less than 15%, and the method accuracy ranged from 87.4% to 112.5%. The extraction recovery was 83.52%-105.34%, and no matrix effect was observed. The three metabolites (gastrodin, α-isobutylmalic acid, and gymnoside I) were synchronously detected at 0.83 h, suggesting that militarine was rapidly transformed to gastrodin, α-isobutylmalic acid, and gymnoside I. Moreover, the area under the curve (AUC) and Cmax of militarine were significantly lower than those of gastrodin and α-isobutylmalic acid, showing that militarine was largely metabolized to gastrodin and α-isobutylmalic acid in vivo. The studies on pharmacokinetics of militarine and its three metabolites were of great use for facilitating the clinical application of militarine and were also highly meaningful for the potential development of militarine.

scholarly journals Reverse phase-liquid chromatography assisted protocol for simultaneous determination of lamivudine and tenofovir disoproxil fumarate in combined medication used to control HIV infection: an investigative approach

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Vaibhav S. Adhao ◽  
Suraj R. Chaudhari ◽  
Jaya P. Ambhore ◽  
Sunil Sangolkar ◽  
Raju R. Thenge ◽  
...  
Keyword(s):  
Liquid Chromatography ◽  
Hiv Infection ◽  
Simultaneous Determination ◽  
Tenofovir Disoproxil Fumarate ◽  
Solvent System ◽  
Array Detector ◽  
Technical Requirements ◽  
Relative Standard ◽  
Limit Of Quantitation

Abstract Background Human immunodeficiency virus (HIV) causes severe life-threatening condition, i.e., AIDS. HIV destabilises an individual’s ability to prevent infection. Therefore, the combine medication lamivudine (LVD) and tenofovir disoproxil fumarate (TDF) are prescribed to suppress the amount of HIV infection in individual’s body; thus, the individual’s immune system could function properly. Consequently, the objective of present research work was to investigate robust and sensitive liquid chromatography avenue for simultaneous determination of lamivudine and tenofovir disoproxil fumarate in pure material and combined dosage form. Results The reversed-phase chromatographic separation has been performed through Hypersil BDS C18 column using solvent system composed of 10 mM potassium dihydrogen phosphate (pH 4.0): acetonitrile (60:40% v/v). The determination was executed at 30 oC at 1 mL/min rate for flow of solvent system through column. The eluents of column were monitored at 265 nm using Photodiode Array detector has revealed admirable retention times, i.e., 4.67 and 8.78 min for both drugs, respectively. The calibration curve demonstrated excellent linearity in the range of 10–50 μg/mL for lamivudine and tenofovir disoproxil fumarate with better determination coefficients was more than (r2 0.999). Conclusion The estimable method was effectively validated with respect to accuracy, precision, sensitive (limit of detection and limit of quantitation), robustness, ruggedness, and for selectivity and specificity. The value less than 2 for percentage relative standard deviation for accuracy, precision, robustness, and ruggedness satisfying the acceptance criteria as per procedure of International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use.

scholarly journals Determination of 77 Multiclass Pesticides and Their Metabolitesin Capsicum and Tomato Using GC-MS/MS and LC-MS/MS

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 1837
Author(s):  
Harischandra Naik Rathod ◽  
Bheemanna Mallappa ◽  
Pallavi Malenahalli Sidramappa ◽  
Chandra Sekhara Reddy Vennapusa ◽  
Pavankumar Kamin ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Solid Phase ◽  
Graphitized Carbon Black ◽  
Limit Of Quantification ◽  
Gas And Liquid Chromatography ◽  
Relative Standard ◽  
The Matrix ◽  
Liquid Chromatography Tandem Mass ◽  
Primary Secondary Amine

A quick, sensitive, and reproducible analytical method for the determination of 77 multiclass pesticides and their metabolites in Capsicum and tomato by gas and liquid chromatography tandem mass spectrometry was standardized and validated. The limit of detection of 0.19 to 10.91 and limit of quantification of 0.63 to 36.34 µg·kg−1 for Capsicum and 0.10 to 9.55 µg·kg−1 (LOD) and 0.35 to 33.43 µg·kg−1 (LOQ) for tomato. The method involves extraction of sample with acetonitrile, purification by dispersive solid phase extraction using primary secondary amine and graphitized carbon black. The recoveries of all pesticides were in the range of 75 to 110% with a relative standard deviation of less than 20%. Similarly, the method precision was evaluated interms of repeatability (RSDr) and reproducibility (RSDwR) by spiking of mixed pesticides standards at 100 µg·kg−1 recorded anRSD of less than 20%. The matrix effect was acceptable and no significant variation was observed in both the matrices except for few pesticides. The estimated measurement uncertainty found acceptable for all the pesticides. This method found suitable for analysis of vegetable samples drawn from market and farm gates.

scholarly journals SENSITIVE DETERMINATION OF RELATED SUBSTANCES IN PIOGLITAZONE HYDROCHLORIDE BY HPLC

2017 ◽  
Vol 9 (2) ◽  
pp. 34
Author(s):  
N. Balaji ◽  
Sayeeda Sultana
Keyword(s):  
Mobile Phase ◽  
High Performance ◽  
Limit Of Detection ◽  
High Performance Liquid Chromatographic ◽  
Hplc Method ◽  
Internal Diameter ◽  
Related Substances ◽  
Relative Standard ◽  
Limit Of Quantitation

Objective: An efficient, high performance liquid chromatographic method has been developed and validated for the quantification of related substances in pioglitazone hydrochloride drug substance.Methods: This method includes the determination of three related substances in pioglitazone hydrochloride. The mobile phase A is 0.1% w/v triethylamine in water with pH 2.5 adjusted by dilute phosphoric acid. The mobile phase B is premixed and degassed mixtures of acetonitrile and methanol. The flow rate was 1 ml/min. The elution used was gradient mode. The HPLC column used for the analysis was symmetry C18 with a length of 250 mm, the internal diameter of 4.6 mm and particle size of 5.0 microns.Results: The developed method was found to be linear with the range of 0.006-250% with a coefficient of correlation 0.99. The precision study revealed that the percentage relative standard deviation was within the acceptable limit. The limit of detection and limit of quantitation of the impurities was less than 0.002%and 0.006% with respect to pioglitazone hydrochloride test concentration of 2000 µg/ml respectively. This method has been validated as per ICH guidelines Q2 (R1).Conclusion: A reliable, economical HPLC method was magnificently established for quantitative analysis of related substances of pioglitazone hydrochloride drug substance.

scholarly journals Determination of Tianeptine in Tablets by High-Performance Liquid Chromatography with Fluorescence Detection

2007 ◽  
Vol 90 (3) ◽  
pp. 720-724
Author(s):  
Sevgi Tatar Ulu
Keyword(s):  
Lower Limit ◽  
High Performance ◽  
Limit Of Detection ◽  
Internal Standard ◽  
Linear Calibration ◽  
Fluorescence Detector ◽  
Relative Standard ◽  
Validation Parameters ◽  
Limit Of Quantitation

Abstract A sensitive and selective high-performance liquid chromatographic method has been developed for the determination of tianeptine (Tia) in tablets. The method is based on derivatization of Tia with 4-chloro-7-nitrobenzofurazan (NBD-Cl). A mobile phase consisting of acetonitrile10 mM orthophosphoric acid (pH 2.5; 77 + 23) was used at a flow rate of 1 mL/min on a C18 column. The Tia-NBD derivative was monitored using a fluorescence detector, with emission set at 520 nm and excitation at 458 nm. Gabapentin was selected as an internal standard. Linear calibration graphs were obtained in the concentration range of 45300 ng/mL. The lower limit of detection (LOD) was 10 ng/mL at a signal-to-noise ratio of 4. The lower limit of quantitation (LOQ) was 45 ng/mL. The relative standard values for intra- and interday precision were &lt;0.46 and &lt;0.57%, respectively. The recovery of the drug samples ranged between 98.89 and 99.85%. No chromatographic interference from the tablet excipients was found. The proposed method was validated in terms of precision, robustness, recovery, LOD, and LOQ. All the validation parameters were within the acceptance range. The proposed method was applied for the determination of Tia in commercially available tablets. The results were compared with those obtained by an ultraviolet spectrophotometric method using t- and F-tests.

scholarly journals Determination of 7B3 Residues in Cotton Plants by Liquid Chromatography/Mass Spectrometry

2009 ◽  
Vol 92 (1) ◽  
pp. 302-306 ◽  
Author(s):  
Xiao-Jing Yan ◽  
Xiao-Mei Liang ◽  
Yan-Jun Xu ◽  
Shu-Hui Jin ◽  
Dao-Quan Wang
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Limit Of Detection ◽  
Reversed Phase ◽  
Liquid Chromatography Mass Spectrometry ◽  
Chromatography Mass Spectrometry ◽  
Relative Standard ◽  
Limit Of Quantitation ◽  
Cotton Plants

Abstract A method was developed for the determination of 7B3 (12-propyloxyimino-1,15-pentadecanlactam), a novel macrolactam fungicide, by liquid chromatography/mass spectrometry (LC/MS) with positive electrospray ionization (ESI+). The method used a reversed-phase C18 column and acetonitrilewater (60 + 40, v/v) mobile phase. The quick, easy, cheap, effective, rugged, and safe method was used for extraction of 7B3 from cotton plants, which involved the extraction of 10 g homogenized sample with 10 mL acetonitrile, followed by the addition of 4 g anhydrous MgSO4 and 1.0 g NaCl. After centrifugation, 1 mL of the buffered acetonitrile extract was transferred into a tube containing 50 mg primary secondary amine sorbent and 100 mg anhydrous MgSO4. After shaking and centrifugation, the final extract was transferred to an autosampler vial for concurrent analysis by LC/MS. The results of 7B3 determined by LC/MS in the selective ion monitoring mode were linear, and the matrix effect of the method was evaluated. The average recoveries of 7B3 fortified at different levels were within 84.1100.2, and the relative standard deviations were &lt;7.5 for all samples analyzed. The method limit of detection and the limit of quantitation values were 0.03 and 0.1 mg/kg, respectively. The proposed method was successfully applied to determine 7B3 residues in practical samples. This method is sensitive, accurate, reliable, simple, and safe.

scholarly journals DEVELOPMENT AND VALIDATION OF ULTRAVIOLET-SPECTROPHOTOMETRIC METHOD FOR DETERMINATION OF FEBUXOSTAT FOR CONDUCTING IN-VITRO QUALITY CONTROL TESTS IN BULK AND PHARMACEUTICAL DOSAGE FORMS

2018 ◽  
Vol 11 (9) ◽  
pp. 115
Author(s):  
Jaspreet Kaur ◽  
Daljit Kaur ◽  
Sukhmeet Singh
Keyword(s):  
Spectrophotometric Method ◽  
Limit Of Detection ◽  
Pharmaceutical Formulations ◽  
Dosage Forms ◽  
Pharmaceutical Dosage Forms ◽  
Relative Standard ◽  
Limit Of Quantitation ◽  
Development And Validation

Objective: A simple, accurate, and selective ultraviolet-spectrophotometric method has been developed for the estimation of febuxostat in the bulk and pharmaceutical dosage forms.Method: The method was developed and validated according to International Conference on Harmonization (ICH Q2 R1) guidelines. The developed method was validated statistically with respect to linearity, range, precision, accuracy, ruggedness, limit of detection (LOD), limit of quantitation (LOQ), and recovery. Specificity of the method was demonstrated by applying different stressed conditions to drug samples such as acid hydrolysis, alkaline hydrolysis, oxidative, photolytic, and thermal degradation.Results: The study was conducted using phosphate buffer pH 6.8 and λmax was found to be 312 nm. Standard plot having a concentration range of 1–10 μg/ml showed a good linear relationship with R2=0.999. The LOD and LOQ were found to be 0.118 μg/ml and 0.595 μg/ml, respectively. Recovery and percentage relative standard deviations were found to be 100.157±0.332% and <2%, respectively.Conclusion: Proposed method was successfully applicable to the pharmaceutical formulations containing febuxostat. Thus, the developed method is found to be simple, sensitive, accurate, precise, reproducible, and economical for the determination of febuxostat in pharmaceutical dosage forms.

scholarly journals Determination of carcinogenic herbicides in milk samples using green non-ionic silicone surfactant of cloud point extraction and spectrophotometry

2018 ◽  
Vol 5 (4) ◽  
pp. 171500 ◽  
Author(s):  
N. I. Mohd ◽  
N. N. M. Zain ◽  
M. Raoov ◽  
S. Mohamad
Keyword(s):  
Cloud Point ◽  
Cloud Point Extraction ◽  
Limit Of Detection ◽  
Cost Effective ◽  
Silicone Surfactant ◽  
Extraction Solvent ◽  
Milk Samples ◽  
Relative Standard ◽  
Limit Of Quantitation

A new cloud point methodology was successfully used for the extraction of carcinogenic pesticides in milk samples as a prior step to their determination by spectrophotometry. In this work, non-ionic silicone surfactant, also known as 3-(3-hydroxypropyl-heptatrimethylxyloxane), was chosen as a green extraction solvent because of its structure and properties. The effect of different parameters, such as the type of surfactant, concentration and volume of surfactant, pH, salt, temperature, incubation time and water content on the cloud point extraction of carcinogenic pesticides such as atrazine and propazine, was studied in detail and a set of optimum conditions was established. A good correlation coefficient ( R 2 ) in the range of 0.991–0.997 for all calibration curves was obtained. The limit of detection was 1.06 µg l −1 (atrazine) and 1.22 µg l −1 (propazine), and the limit of quantitation was 3.54 µg l −1 (atrazine) and 4.07 µg l −1 (propazine). Satisfactory recoveries in the range of 81–108% were determined in milk samples at 5 and 1000 µg l −1 , respectively, with low relative standard deviation, n  = 3 of 0.301–7.45% in milk matrices. The proposed method is very convenient, rapid, cost-effective and environmentally friendly for food analysis.

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