scholarly journals Development of a sensitive and stable GC-MS/MS method for simultaneous determination of four N-nitrosamine genotoxic impurities in sartan substances

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jie Liu ◽  
Bin Xie ◽  
Binliang Mai ◽  
Qiang Cai ◽  
Rujian He ◽  
...  
Keyword(s):  
Simultaneous Determination ◽  
Internal Standard ◽  
The United States ◽  
Fast Analysis ◽  
Standard Curve ◽  
Multiple Reactions ◽  
Relative Standard ◽  
Genotoxic Impurities ◽  
Linearity Of Regression

AbstractRecently, N-nitrosamines have been unexpectedly found in generic sartan products. Herein, we developed a sensitive and stable GC-MS/MS method with multiple reactions monitoring mode for the simultaneous determination of four N-nitrosamines in sartan substances, namely, N-nitrosodimethylamine, N-nitrosodiethylamine, N-nitrosodibutylamine, and N-nitrosodiisopropylamine. The conditions of gas chromatography and mass spectrometry were optimized. The method was validated according to the International Council for Harmonization guidelines in terms of sensitivity, linearity, accuracy, precision, specificity, and stability. The limits of detection of N-nitrosamines in sartan substances ranged from 0.002 to 0.150 ppm, and the corresponding limits of quantification were in the range of 0.008-0.500 ppm, which met the sensitivity requirements for the limits set by the Food and Drug Administration of the United States. The internal standard curve of four N-nitrosamines showed good linearity of regression coefficients over 0.99. The recoveries of N-nitrosamines in selected sartan drugs ranged from 87.68 to 123.76%. The intraday and interday relative standard deviation values were less than 9.15%. Therefore, this proposed method exhibited good sensitivity and precision, high accuracy, and fast analysis speed, which provide a reliable method for quality control of N-nitrosamines in sartan products.

Gas Chromatographic-Thermal Energy Analysis Method for Determination of Volatile N-Nitrosamines in Baby Bottle Rubber Nipples: Collaborative Study

1987 ◽  
Vol 70 (1) ◽  
pp. 64-68 ◽  
Author(s):  
J Ian Gray ◽  
Michael A Stachiw
Keyword(s):  
Thermal Energy ◽  
Energy Analysis ◽  
Collaborative Study ◽  
Internal Standard ◽  
Analytical Techniques ◽  
The United States ◽  
Baby Bottle ◽  
Relative Standard ◽  
Better Than

Abstract A collaborative study was conducted on the U.S. Food and Drug Administration (FDA) dichloromethane extraction method for determining volatile N-nitrosamines in baby bottle rubber nipples. Following dichloromethane extraction, A'-nitrosamines were determined by gas chromatography-thermal energy analysis. Six pairs of blind duplicate rubber nipple samples representing 6 lots were analyzed by 11 collaborating laboratories. All samples were portions taken from equilibrated composites of cut-up rubber nipples obtained from manufacturers in the United States. Recoveries of the internal standard (N-nitrosodipropylamine) at approximately 20 ppb ranged from 10 to 120%. Reproducibility relative standard deviations (RSDJ were between 35 and 45% for N-nitrosamine levels from 10 to 20 ppb. However, when data from laboratories with recoveries less than 75% were excluded (this is now specified in the method), RSD„ values were between 11 and 32% for N-nitrosamine levels from 6 to 26 ppb. Values were consistent with or better than those reported for other analytical techniques designed to quantitate trace contaminants at the low ppb level, e.g., afiatoxin in foods. The method has been adopted official first action for the quantitation of volatile N-nitrosamines in baby bottle rubber nipples.

scholarly journals UPLC–MS/MS simultaneous determination of methamphetamine, amphetamine, morphine, monoacetylmorphine, ketamine, norketamine, MDMA, and MDA in hair

2020 ◽  
Vol 32 (2) ◽  
pp. 145-148 ◽  
Author(s):  
Siyuan Chen ◽  
Jianshe Ma ◽  
Xianqin Wang ◽  
Peiwu Geng
Keyword(s):  
Simultaneous Determination ◽  
Multiple Reaction Monitoring ◽  
Internal Standard ◽  
Correlation Coefficients ◽  
Ammonium Hydroxide ◽  
Ultra Performance Liquid Chromatography ◽  
Acetate Solution ◽  
Hair Samples ◽  
Relative Standard

Hair is a stable specimen and has a longer detection window (from weeks to months) than blood and urine. Through the analysis of hair, the long-term information of the drug use of the identified person could be explored. Our work is to establish an ultra-performance liquid chromatography–tandem mass spectroscopy (UPLC–MS/MS) method for simultaneous determination of methamphetamine, amphetamine, morphine, monoacetylmorphine, ketamine, norketamine, 3,4-methylenedioxymethamphetamine (MDMA), and 3,4-methylenedioxyamphetamine (MDA) in hair. Methoxyphenamine was used as an internal standard. The chromatographic separation was performed on a UPLC ethylene bridged hybrid (BEH) C18 (2.1 mm × 50 mm, 1.7 μm) column using a mobile phase of acetonitrile–water with 10 mmol/L ammonium acetate solution which containing 0.05% ammonium hydroxide. The multiple reaction monitoring in positive electrospray ionization was used for quantitative determination. The intra-day and inter-day precisions (relative standard deviation [RSD]) were below 15%. The accuracy ranged between 85.5% and 110.4%, the average recovery rate was above 72.9%, and the matrix effect ranged between 92.7% and 109.2%. Standard curves were in the range of 0.05–5.0 ng/mg, and the correlation coefficients were greater than 0.995. The established UPLC–MS/MS method was applied to analyze the hair samples successfully.

scholarly journals Simultaneous Determination of Benzene and Toluene in Pesticide Emulsifiable Concentrate by Headspace GC-MS

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Lidong Cao ◽  
Hua Jiang ◽  
Jing Yang ◽  
Li Fan ◽  
Fengmin Li ◽  
...  
Keyword(s):  
Simultaneous Determination ◽  
Internal Standard ◽  
Fused Silica ◽  
Gas Chromatography Mass Spectrometry ◽  
Equilibration Time ◽  
Emulsifiable Concentrate ◽  
Pesticide Formulations ◽  
Relative Standard ◽  
Standard Additions

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.

A high-performance liquid-chromatographic method for routine simultaneous determination of nicotine and cotinine in plasma.

1988 ◽  
Vol 34 (4) ◽  
pp. 724-729 ◽  
Author(s):  
M Hariharan ◽  
T VanNoord ◽  
J F Greden
Keyword(s):  
Simultaneous Determination ◽  
Mobile Phase ◽  
High Performance ◽  
Methylene Chloride ◽  
Internal Standard ◽  
High Performance Liquid Chromatographic ◽  
Reversed Phase ◽  
Standard Curve ◽  
Liquid Chromatographic

Abstract We describe a rapid, sensitive method for the routine simultaneous determination of nicotine and cotinine in 1 mL of plasma. Extraction in 10-mL screw-capped Teflon tubes with methylene chloride after deproteinization with trichloroacetic acid eliminated emulsion formation. The extract, after evaporation and reconstitution in 30 microL of mobile phase, is injected into a reversed-phase C-18 ion-pair column of an isocratic high-performance liquid-chromatographic unit. Absorbance is monitored at 256 nm. The mobile phase is a citrate-phosphate (30 mmol each per liter) buffer mixture containing 50 mL of acetonitrile and 1 mmol of sodium heptanesulfonate per liter. 2-Phenylimidazole is the internal standard. The detection limit is 1 microgram/L for nicotine and 3 micrograms/L for cotinine. The standard curve is linear from 0 to 700 micrograms/L for both compounds. The average CV for nicotine in the concentration range 0-100 micrograms/L is 6.5%, and that for cotinine in the concentration range 50-700 micrograms/L is 4%.

Simultaneous Determination of Quercitrin, Afzelin, Amentoflavone, Hinokiflavone in Rat Plasma by UFLC–MS-MS and Its Application to the Pharmacokinetics of Platycladus orientalis Leaves Extract

2018 ◽  
Vol 56 (10) ◽  
pp. 895-902 ◽  
Author(s):  
Chen-xiao Shan ◽  
Shu-chen Guo ◽  
Sheng Yu ◽  
Ming-qiu Shan ◽  
Sam Fong Yau Li ◽  
...  
Keyword(s):  
Simultaneous Determination ◽  
Pharmacokinetic Study ◽  
Internal Standard ◽  
Gradient Elution ◽  
Rat Plasma ◽  
Platycladus Orientalis ◽  
Chromatography Tandem Mass Spectrometry ◽  
Relative Standard ◽  
Liquid Chromatography Tandem Mass

Abstract Leaves of Platycladus orientalis have been used as blood cooling and homeostatic therapy for thousands of years in traditional Chinese medicine. Emerging evidences of modern pharmacology have proved flavonoids as the key elements responsible for the efficacies. However, there has been no report on pharmacokinetic study of the flavonoids from Platycladus orientalis leaves extract. In this study, a sensitive and rapid ultra-flow liquid chromatography-tandem mass spectrometry method was established and validated for the simultaneous determination of amentoflavone, afzelin, hinokiflavone and quercitrin in rat plasma. The four flavonoids and luteolin (internal standard, IS) were recovered from rat plasma by methanol–ethyl acetate (v:v, 50:50). Chromatographic separation was performed on a C18 column with gradient elution. Our results showed that the recoveries from spiked control samples were more than 85% for all analytes and IS. The relative standard deviations of intra-day and inter-day precision were within 15% while the REs ranged from −6.6% to 8.0%. The validated method in this study was successfully applied to pharmacokinetic study in healthy rats after oral administration of P. orientalis leaves extract.

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 Simultaneous Determination of Residues of Chloramphenicol, Florfenicol, Florfenicol Amine, and Thiamphenicol in Shrimp Tissue by Gas Chromatography with Electron Capture Detection

2000 ◽  
Vol 83 (1) ◽  
pp. 26-30 ◽  
Author(s):  
Allen P Pfenning ◽  
José E Roybal ◽  
Heidi S Rupp ◽  
Sherri B Turnipseed ◽  
Steve A Gonzales ◽  
...  
Keyword(s):  
Ethyl Acetate ◽  
Electron Capture ◽  
Solid Phase ◽  
Internal Standard ◽  
Electron Capture Detection ◽  
Organic Layer ◽  
Standard Curve ◽  
Quantitation Limit ◽  
Relative Standard

Abstract A gas chromatographic (GC) method is presented for determining residues of chloramphenicol (CAP), florfenicol (FF), florfenicol amine (FFa), and thiamphenicol (TAP) in shrimp tissues, with meta-nitrochloramphenicol (mCAP) as the internal standard. The composited shrimp is extracted with basic ethyl acetate, followed by an acetonitrile–basic ethyl acetate mixture. This extract is centrifuged, filtered, evaporated, and reconstituted in water; the reconstituted extract is acidified, defatted with hexane, and passed through a propylsulfonic acid (PRS) and C18 solid-phase extraction (SPE) system. The C18 SPE column is eluted with methanol, and the PRS SPE column is eluted with basic MeOH plus counter ion. The combined eluates are evaporated, reconstituted in acetonitrile, and derivatized with Sylon BFT. After derivatization, the addition of toluene directly to the sample, followed by the addition of basic water, quenches the derivatization process. After centrifugation, the organic layer is carefully removed, and the analytes are determined by GC with electron capture detection. Shrimp tissues were fortified with fenicols (i.e., CAP, FF, FFa, and TAP) at 5, 10, 20, 40, and 80 ng/mL. Overall recoveries were 88, 101, 91, and 84% with overall interassay (between-day) variabilities (i.e., relative standard deviations) of 5.3, 9.4, 12.8, and 7.4% for CAP, FF, FFa, and TAP, respectively. The method detection limits were calculated as 0.7, 1.4, 2.4, and 1.3 ng/g (ppb) for CAP, FF, FFa, and TAP, respectively, based on a 10 g sample. The quantitation limit as determined empirically by this method is the lower limit of the standard curve, which is about 5 ng/g (ppb) for each analyte.

Simultaneous determination of furan and its derivatives in food by headspace gas chromatography-mass spectrometry (HS-GC-MS)

2021 ◽  
Vol 4 (3) ◽  
pp. 13-23
Author(s):  
Ha Binh Nguyen Thi ◽  
Cao Tien Bui ◽  
Ngoc Anh Mai Thi ◽  
Hoai Pham Thi ◽  
Hong Hao Le Thi ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Simultaneous Determination ◽  
Internal Standard ◽  
Food Samples ◽  
Gas Chromatography Mass Spectrometry ◽  
Powdered Milk ◽  
Chromatography Mass Spectrometry ◽  
Relative Standard

A method for the simultaneous determination of furans, 2-methylfuran and 3-methylfuran in some food by gas chromatography-mass spectrometry (GC-MS) has successfully developed. Analysed samples were treated by a headspace technique using furan-d4 as an internal standard. The detection limit of the method is 0.3 µg/kg, the quantitative limit of the method is 1.0 µg/kg. The recovery of the method is in the range of 72 to 110%. The relative standard deviation ranges from 3.3 to 13%. The method was applied to analyze 100 food samples, including: coffees, canned meats, baby foods, powdered milk. The results showed that furans, 2-methylfuran, 3-methylfuran were detected in 30 samples out of 100 collected samples. In particular, furans were found in a ranges of 5.7 to 2803 µg/kg in all of coffee samples, including instant coffee and roasted coffee. In addition, furans were detected in one baby food sample contains, furans and 2-methylfuran in four canned meat samples, and no furans milk were detected in powder sample among 25 analysed samples.

Determination of Antimony in Lead-Antimony Alloys by Atomic Absorption Spectroscopy Using Indium as an Internal Standard

1979 ◽  
Vol 33 (5) ◽  
pp. 468-470 ◽  
Author(s):  
Gary W. Kramer
Keyword(s):  
Atomic Absorption ◽  
Internal Standard ◽  
The United States ◽  
Alternative Methods ◽  
Standard Reference Materials ◽  
United States Department ◽  
Internal Standard Method ◽  
Relative Standard ◽  
Antimony Alloys

A rapid, precise analytical method has been developed by the United States Department of the Interior, Bureau of Mines, for the determination of antimony in lead-antimony alloys. The alloy (0.10 to 30.0 wt.% Sb) is rapidly dissolved in a 10% volume nitric acid solution containing ∼5 g of tartaric acid. Antimony is determined by atomic absorption using indium as an internal standard. The relative standard deviation for this internal standard method, based on the analysis of three National Bureau of Standards (NBS) Standard Reference Materials, is approximately 0.50%; an improvement over conventional atomic absorption and a volumetric method by a factor of 5 to 8. The internal standard procedure gives values that are in better agreement with the NBS certified values than analyses using the alternative methods. Analytical time required is less than 30 min.

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