scholarly journals Development and validation of a GC–MS method for the simultaneous determination of acetochlor, fluorochloridone, and pendimethalin in a herbicide emulsifiable concentrate formulation

2020 ◽  
Vol 32 (4) ◽  
pp. 238-241 ◽  
Author(s):  
Dandan Wang ◽  
Shengde Wu

This paper describes a rapid method to simultaneously determine acetochlor, fluorochloridone and pendimethalin present in a herbicide emulsifiable concentrate (EC) formulation using gas chromatography–mass spectrometry (GC–MS). Selected ion monitoring mode was performed to increase the sensitivity, with dibutyl phthalate as an internal standard. The method was validated with respect to linearity, accuracy, precision, and stability. Chromatographic separation was carried out on a TG-5 MS column (30 m × 0.25 mm × 0.25 μm) with helium as the carrier gas at a flow rate of 1.0 mL/min. Calibration curves were linear over 2.0–20.0 μg/mL for each analyte, and the limit of quantification was below 20 ng/mL. Good performance in terms of recovery ranging from 94.5% to 102.5% at 3 concentration levels proved excellent accuracy. The intra- and inter-day relative standard deviations for 6 replicate measurements were always less than 5%. The developed method is simple and efficient for the routine determination of the ternary mixtures in a compound herbicide EC formulation product.

2016 ◽  
Vol 13 (4) ◽  
pp. 341-347
Author(s):  
Wei Gao ◽  
Naiying Wu ◽  
Wenliang Sun

Purpose This paper aims to present a robust method for the determination of α- and ß-2, 7, 11-cembratriene-4, 6-diols (α, ß-CBT-diol) in tobacco samples which was developed and validated by using the self-made α, ß-CBT-diol with higher purity as the standard. Design/methodology/approach After the ultrasonic extraction and clean-up procedures, samples were analyzed by gas chromatography/mass spectrometry in selected ion monitoring mode and full scan mode at the same time. A 1-heptadecanol was used as an internal standard. The important parameters, such as extraction conditions and derivation conditions, were optimized. Findings Under the optimal conditions, good results in terms of linearity (R2 > 0.999) and recoveries (93.2-107 per cent) were achieved. The limits of detection were 0.120 and 0.180 μg/ml for α- and ß-CBT-diol, respectively. α, ß-CBT-diol level of analyzed tobacco was found in the range of 34.2-1.26 × 103 μg/g with relative standard deviations below 6 per cent. Originality/value Such a strategy opens a new door towards the development of a simple, robust and sensitive method for the determination of α, ß-CBT-diol in real samples.


2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Lidong Cao ◽  
Hua Jiang ◽  
Jing Yang ◽  
Li Fan ◽  
Fengmin Li ◽  
...  

The toxic inert ingredients in pesticide formulations are strictly regulated in many countries. In this paper, a simple and efficient headspace-gas chromatography-mass spectrometry (HSGC-MS) method using fluorobenzene as an internal standard (IS) for rapid simultaneous determination of benzene and toluene in pesticide emulsifiable concentrate (EC) was established. The headspace and GC-MS conditions were investigated and developed. A nonpolar fused silica Rtx-5 capillary column (30 m×0.20 mmi.d. and 0.25 μm film thickness) with temperature programming was used. Under optimized headspace conditions, equilibration temperature of 120°C, equilibration time of 5 min, and sample size of 50 μL, the regression of the peak area ratios of benzene and toluene to IS on the concentrations of analytes fitted a linear relationship well at the concentration levels ranging from 3.2 g/L to 16.0 g/L. Standard additions of benzene and toluene to blank different matrix solutions 1ead to recoveries of 100.1%–109.5% with a relative standard deviation (RSD) of 0.3%–8.1%. The method presented here stands out as simple and easily applicable, which provides a way for the determination of toxic volatile adjuvant in liquid pesticide formulations.


1988 ◽  
Vol 71 (6) ◽  
pp. 1183-1186 ◽  
Author(s):  
Laurence Castle ◽  
Matthew Sharman ◽  
John Gilbert

Abstract A method for the quantitative determination of epoxidized soybean oil (ESBO) in foods is described. The procedure involves addition of a diepoxidized fatty acid ester internal standard, followed by lipid extraction from the food and transmethylation under basic conditions. Without further cleanup, the methylated fatty acid epoxides are derivatized to form 1,3-dioxolanes, which are then determined by capillary gas chromatography-mass spectrometry with selected ion monitoring. A detection limit of 2.0 mg/kg of epoxidized soybean oil in foods and a relative standard deviation of 7% have been achieved routinely. The method has been applied successfully to the analysis of cheeses, sandwiches, cakes, and microwave-cooked meals which have been contaminated with ESBO by migration from PVC film.


2018 ◽  
Vol 15 (1) ◽  
pp. 39-44 ◽  
Author(s):  
Feng Su ◽  
Zi-qing Sun ◽  
Xian-rui Liang

Introduction: Quantitative NMR spectroscopy (qNMR) is a rapid, simple and efficient method for the assay of sulfasalazine (SSZ) in commercial tablet formulation. Materials and Methods: The qNMR method was demonstrated using maleic acid as an internal standard and DMSO-d6 as a solvent. The characteristic signals of SSZ at δ 8.36 ppm and maleic acid at δ 6.28 ppm were quantified. The reliability of the quantification method had been implemented successfully in validated experiments including specificity and selectivity, linearity, recovery, precision concentration rang, limit of detection (LOD), limit of quantification (LOQ), stability and robustness. Conclusion: The method was found to be liner (R2 = 0.9991) from 8.62 to 20.14 mg/0.6 mL DMSO-d6 in the drug concentration range. The maximum relative standard deviation (RSD) of recovery and precision were tested to be 0.59% and 0.65%, respectively. The LOD and LOQ were determined to be 0.02, 0.07 mg/mL, respectively. The RSD of stability was 0.05%. The robustness was demonstrated by changing four different parameters with the maximum difference less than 0.9%. In addition, the result of qNMR showed in good agreement with the HPLC and UV methods. Based on the experiments, the developed method was successfully applied to the determination of SSZ in commercial tablet.


2020 ◽  
Vol 16 (4) ◽  
pp. 428-435
Author(s):  
Ahmed F.A. Youssef ◽  
Yousry M. Issa ◽  
Kareem M. Nabil

Background: Simeprevir is one of the recently discovered drugs for treating hepatitis C which is one of the major diseases across the globe. Objective: The present study involves the development of a new and unique High-Performance Liquid Chromatography (HPLC) method using fluorescence detection for the determination of simeprevir (SIM) in human plasma. Methods: Two methods of extractions were tested, protein precipitation using acetonitrile and liquidliquid extraction. A 25 mM dipotassium hydrogen orthophosphate (pH 7.0)/ACN (50/50; v/v), was used as mobile phase and C18 reversed phase column as the stationary phase. The chromatographic conditions were optimized and the concentration of simeprevir was determined by using the fluorescence detector. Cyclobenzaprine was used as an internal standard. Results: Recovery of the assay method based on protein precipitation was up to 100%. Intra-day and inter-day accuracies range from 92.30 to 107.80%, with Relative Standard Deviation (RSD) range 1.65-8.02%. The present method was successfully applied to a pharmacokinetic study where SIM was administered as a single dose of 150 mg SIM/capsule (Olysio®) to healthy individuals. Conclusion: This method exhibits high sensitivity with a low limit of quantification 10 ng mL-1, good selectivity using fluorescence detection, wide linear application range 10-3000 ng mL-1, good recovery and highly precise and validation results. The developed method can be applied in routine analysis for real samples.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Indhu Priya Mabbu ◽  
G. Sumathi ◽  
N. Devanna

Abstract Background The aim of the present method is to develop and validate a specific, sensitive, precise, and accurate liquid chromatography-mass spectrometry (LC-MS) method for the estimation of the phenyl vinyl sulfone in the eletriptan hydrobromide. The effective separation of the phenyl vinyl sulfone was achieved by the Symmetry C18 (50 × 4.6 mm, 3.5 μm) column and a mobile phase composition of 0.1%v/v ammonia buffer to methanol (5:95 v/v), using 0.45 ml/min flow rate and 20 μl of injection volume, with methanol used as diluent. The phenyl vinyl sulfone was monitored on atomic pressure chemical ionization mode mass spectrometer with positive polarity mode. Results The retention time of phenyl vinyl sulfone was found at 2.13 min. The limit of detection (LOD) and limit of quantification (LOQ) were observed at 1.43 ppm and 4.77 ppm concentration respectively; the linear range was found in the concentration ranges from 4.77 to 27.00 ppm with regression coefficient of 0.9990 and accuracy in the range of 97.50–102.10%. The percentage relative standard deviation (% RSD) for six replicates said to be injections were less than 10%. Conclusion The proposed method was validated successfully as per ICH guidelines. Hence, this is employed for the determination of phenyl vinyl sulfone in the eletriptan hydrobromide.


2012 ◽  
Vol 11 (1) ◽  
pp. 55-63 ◽  
Author(s):  
Maizbha Uddin Ahmed ◽  
Mohammad Safiqul Islam ◽  
Tasmin Ara Sultana ◽  
AGM Mostofa ◽  
Muhammad Shahdaat Bin Sayeed ◽  
...  

Azithromycin is an effective and well-known antimicrobial agent. In the present study, a simple, sensitive and specific LC/MS/MS method has been developed and validated for the quantification of Azithromycin in  human serum samples using Clarithromycin as internal standard. Azithromycin was extracted from biological matrix  by using solid phase extraction process. The chromatographic separation was performed on Luna C18 (3 ?, 2x150   mm) column with a mobile phase consisting of 35 mM ammonium acetate buffer (mobile phase-A) and acetonitrile  and methanol in ratio of 90:10 ( as mobile phase-B) at a flow rate of 0.25 mL/min. The method was validated over a  linear concentration range of 0.5?50.0 ng/mL and limit of quantification (LOQ) was 0.5 ng/mL with a coefficient of  correlation (r2) = 0.9998. The intra-day and inter-day precision expressed as relative standard deviation were 1.64% – 8.43% and 2.32% – 9.92%, respectively. The average recovery of azithromycin from serum was 98.11%. The method  was successfully applied to a pharmacokinetic study after oral administration of Azithromycin 200 mg/5 ml suspension in healthy Bangladeshi volunteers. DOI: http://dx.doi.org/10.3329/dujps.v11i1.12488 Dhaka Univ. J. Pharm. Sci. 11(1): 55-63, 2012 (June)


2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Giulio Mannocchi ◽  
Flaminia Pantano ◽  
Roberta Tittarelli ◽  
Miriam Catanese ◽  
Federica Umani Ronchi ◽  
...  

Introduction. Clotiapine is an atypical antipsychotic of the dibenzothiazepine class introduced in a few European countries since 1970, efficient in treatment-resistant schizophrenic patients. There is little published data on the therapeutic and toxic concentrations of this drug.Aims. The aim of the present study is the development and validation of a method that allows the detection and quantification of clotiapine in blood and urine specimens by gas chromatography-mass spectrometry (GC-MS).Methods. Validation was performed working on spiked postmortem blood and urine samples. Samples were extracted with liquid-liquid extraction (LLE) technique at pH 8.5 with n-hexane/dichloromethane (85/15 v/v) and analysis was followed by GC-MS. Methadone-d9 was used as internal standard.Results. The limit of detection (LOD) was 1.2 and 1.3 ng/mL for urine and blood, respectively, while the lower limit of quantification (LLOQ) was 3.9 and 4.3 ng/mL, respectively. Linearity, precision, selectivity, accuracy, and recovery were also determined. The method was applied to a postmortem case. The blood and urine clotiapine concentrations were 1.32 and 0.49 μg/mL, respectively.Conclusions. A reliable GC-MS method for the detection and quantification of clotiapine in blood and urine samples has been developed and fully validated and then applied to a postmortem case.


1994 ◽  
Vol 77 (4) ◽  
pp. 917-924 ◽  
Author(s):  
Roger T Wilson ◽  
Joseph M Groneck ◽  
Kathleen P Holland ◽  
A Carolyn Henry

Abstract A gas chromatographic/mass spectrometric procedure is described for the quantitation and confirmation of clenbuterol residues from cattle, sheep, and swine tissues. After liquid–liquid extraction and derivatization with phosgene in an aqueous pH 10.1 buffer, the cyclic oxazolidone derivative is quantitated with a clenbuterol analogue as internal standard (NAB-760 CI). Confirmation is accomplished by comparison of ion ratios with those of a pure synthesized standard of clenbuterol oxazolidin-3-one obtained by selected ion monitoring, electron ionization gas chromatography/mass spectrometry on a benchtop instrument. Statistical information based on a series of standard curves for fortified tissues is included to describe method performance. Ion ratio variations were under 15%, and coefficients of variation for spiked tissue standard curves were above 0.997. Recoveries averaged 87.1 ± 6.6% for liver tissues across all 3 species and 67.1 ± 3.8% for muscle tissue across all 3 species.


1995 ◽  
Vol 78 (4) ◽  
pp. 959-966 ◽  
Author(s):  
Heidi S Rupp ◽  
David C Holland ◽  
Robert K Munns ◽  
Sherri B Turnipseed ◽  
Austin R Long

Abstract A liquid chromatographic (LC) method was developed for the determination of flunixin (FNX) in raw bovine milk. The milk was acidified and mixed with silica gel, and the mixture was packed into a chromatographic column. The column was defatted with water-saturated dichloromethane–hexane (30 + 70, v/v), and the analyte was eluted with EtOAc. The EtOAc extract was washed with water at pH 3.5, the water was discarded, and the EtOAc layer was then extracted with 0.1 M NaOH. The aqueous layer was drained, passed through a primed C18 solid-phase extraction (SPE) column, and eluted with EtOAc. The EtOAc layer was dried under N2, taken up in a solution of MeOH–(5 mM tetrabutylammonium [TBA]–H2PO4 + 2 mM NaOH) (50 + 50), sonicated, and filtered. FNX was determined by LC using a C18 column (ODS Hypersil), a mobile phase mixture of 58% A (MeOH) and 42% B (5 mM TBA–H2PO4 + 2 mM NaOH), and a diode-array ultraviolet detector at 285 nm. FNX was determined in raw milk at 5 spiking levels (5,10,20,40, and 80 ng drug/mL milk). Absolute recoveries ranged from 69.6 to 74.4%, and relative standard deviations ranged from 1.1 to 6.9%. The limit of quantitation was 1.7 ng drug/mL milk. A lactating cow was dosed intravenously (2.2 mg/kg) with flunixin meglumine (Banamine) to generate incurred milk residues. FNX residues ranged from 7.34 ng/mL at 16 h postdose to 1.74 ng/mL at 24 h postdose. Both levels were obtained with additional β-glucuronidase treatment (almost no incurred drug was detected at these low levels without the enzyme treatment). The presence of FNX in incurred milk was confirmed by gas chromatography/mass spectrometry with selected ion monitoring.


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