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.

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.

X-Ray Fluorescence Spectrometric Determination of Rare Earths in Plutonium

1968 ◽  
Vol 22 (5) ◽  
pp. 434-437 ◽  
Author(s):  
E. A. Hakkila ◽  
R. G. Hurley ◽  
G. R. Waterbury
Keyword(s):  
Rare Earths ◽  
Internal Standard ◽  
Internal Standard Method ◽  
X Rays ◽  
Measured Intensity ◽  
X Ray ◽  
Low Concentrations ◽  
Relative Standard ◽  
Intensity Ratios

Two methods were evaluated for determining rare earths in plutonium: (1) For the lighter rare earths ( Z≦66), or low concentrations of the heavier rare earths, an adjacent rare earth was added as a carrier and also as an internal standard, the rare earths were separated from plutonium by fluoride precipitation, and the measured intensity ratios for the sample and for solutions having known concentrations were compared. The Lβ1 x-rays were measured for the lighter rare earths and the Lα1 x rays for the remaining lanthanides. (2) For the heavier rare earths ( Z>66), the Lα1 x-ray intensities were measured from a nitric acid solution of the sample and compared to intensities obtained for solutions having known concentrations. The minimum concentrations that could be measured with a relative standard deviation no greater than 4% by the separation internal standard method varied from approximately 0.5% for lanthanum to 0.01% for lutetium. The direct measurement of x-ray intensity was much less sensitive. Applicability of the methods was shown by successful analyses of plutonium alloys containing dysprosium, thulium, or lutetium.

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.

Determination of Ethanol in Fermented Broth by Headspace Gas Chromatography using Capillary Column

2018 ◽  
Vol 69 (11) ◽  
pp. 2969-2972
Author(s):  
Asem Hassan Mohammed ◽  
Alaa Kareem Mohammed ◽  
Firas Hashim Kamar ◽  
Aseel Abdulqader Abbas ◽  
Gheorghe Nechifor
Keyword(s):  
Gas Chromatography ◽  
Capillary Column ◽  
Internal Standard ◽  
Accurate Method ◽  
Volatile Components ◽  
Internal Standard Method ◽  
Significance Level ◽  
Relative Standard ◽  
Fermented Broth

The gas chromatography (GC) method in analytical chemistry is a quick and accurate method to detect volatile components like ethanol. A method for determining volatile components known as Headspace chromatography (HS-GC) was developed along with an internal standard method (ISM) to identify ethanol in fermented broth in the laboratory. The aim of this research is determining the concentration of ethanol in fermented broth using capillary column (ZB-1). This method can analyze ethanol concentrations in the fermented medium broth ranging from 10 to 200 g/L. The validation of this method was done in order to obtain the results to be of high precision and the significant, precision was represented as the relative standard deviation (RSD) which was less than 5%, accuracy was less than 4 % and significance level was p [ 0.05. It was found that this method exhibited good reproducibility.

Application of Capillary Zone Electrophoresis in the Separation and Determination of the Tertiary Butylhydroquinone

2011 ◽  
Vol 361-363 ◽  
pp. 683-686
Author(s):  
Qian Xiang ◽  
Ying Gao
Keyword(s):  
Capillary Zone Electrophoresis ◽  
Internal Standard ◽  
Amperometric Detection ◽  
Internal Standard Method ◽  
Tertiary Butylhydroquinone ◽  
Peak Intensity ◽  
Relative Standard ◽  
Zone Electrophoresis ◽  
Capillary Zone

We describe the use of capillary zone electrophoresis (CZE) for the determination of tertiary butylhydroquinone (TBHQ) without derivatization or purification. The influences of buffer pH and voltage on the separation of TBHQ were studied. The internal standard method was used for the quantification of TBHQ. Amperometric detection was carried out at an applied potential of 0.80 V. The detection limit of TBHQ was found to be 10-6 M. Peak intensity varied linearly with TBHQ concentration from 10-4 to 5×10-6 M. The relative standard deviation (RSD) for peak intensity and migration time was in the range of 3.58–4.36% and 0.51–0.94%, respectively. The recovery of the method in food samples is 95.36% for TBHQ. The method developed is suitable for the routine analysis of synthetic phenolic antioxidant TBHQ in samples.

Determination of Migration of 11 Organotin Compounds in Food Contact Materials by GCMS

2020 ◽  
Vol 984 ◽  
pp. 58-63
Author(s):  
Guang Bao Ye
Keyword(s):  
Internal Standard ◽  
Liquid Solution ◽  
Organotin Compounds ◽  
Internal Standard Method ◽  
Method Detection Limit ◽  
Contact Materials ◽  
Food Contact Materials ◽  
Food Contact ◽  
Relative Standard

The determination of the migration of 11 organotin compounds in food contact materials by GC-MS was established. The gastric acid was simulated with 0.07 mol/L hydrochloric acid solution, and the sample was soaked and extracted, and then derivatized with sodium tetraethylborate, extracted with n-hexane liquid solution, detected by GC-MS, and quantified by internal standard method. The linear range of the method is 5~600 μg/L, the correlation coefficient is greater than 0.997, and the method detection limit is 0.014 mg/kg. The recoveries of the three concentration levels ranged from 83.6% to 105.6% with a relative standard deviation of less than 11.4%. The method is simple and sensitive, and can be used for detecting the migration of organotin compounds in food contact materials.

scholarly journals Simultaneous determination of C4-C9 alkylphenols and bisphenol A in environmental water at the Yellow River Estuary Area in China by gas chromatography-mass spectrometry

2021 ◽  
Author(s):  
hailliang yin ◽  
Tongna ZHOU ◽  
ziqi guo ◽  
xinliang liu ◽  
jian ZHAO
Keyword(s):  
Bisphenol A ◽  
Yellow River ◽  
River Estuary ◽  
Internal Standard ◽  
Environmental Water ◽  
Gas Chromatography Mass Spectrometry ◽  
The Yellow River ◽  
Internal Standard Method ◽  
Relative Standard

Abstract A liquid-liquid extraction combined with derivatization and gas chromatography-mass spectrometry (GC-MS) method was developed for the rapid determination of C4-C9 alkylphenols (4-tert-butylphenol, 4-n-butylphenol, 4-n-pentylphenol, 4-n-hexylphenol, 4-n-heptylphenol, 4-n-octylphenol, 4-tert-octylphenol, 4-n-nonylphenol and 4-nonylphenol) and bisphenol A in the environmental water. The extraction solvent, extraction time, solvent volume, acidity, salt content and the distillation degree were optimized. After drying and dehydration, the extract was derivatized, detected by GC-MS and quantified by internal standard method. After the dehydration, the extract was derivatized with BSTFA, detected by GC-MS and quantified by internal standard method. The results showed that the relative standard deviations of the relative response factors of the target compounds were less than 20%, the method detection limits were 0.002 µg/Lཞ0.006 µg/L, the relative standard deviations of the three spiked levels were 0.67%ཞ13.7%, and the average recoveries of the actual water samples were 68.0%ཞ122%. The method precision and accuracy were good. The method is simple, rapid, accurate, stable and reliable, which is suitable for the detection of target in water. The contents of C4-C9 alkylphenols and bisphenol A in groundwater, surface water, sewage, waste water and sea water samples in Dongying City located at the Yellow River Estuary were determined by this method. The results showed that the contents of 4-nonylphenol and bisphenol A in these samples were lower than the home and abroad requirements.

Atomic absorption determination of Hg (II), Cd (II), and As (III) in natural and waste water after preliminary group preconcentration

2019 ◽  
Vol 85 (2) ◽  
pp. 12-16
Author(s):  
I. V. Saunina ◽  
E. N. Gribanov ◽  
E. R. Oskotskaya
Keyword(s):  
Waste Water ◽  
Atomic Absorption ◽  
High Sensitivity ◽  
Distribution Coefficients ◽  
Neutral Medium ◽  
Atomic Absorption Determination ◽  
Absorption Determination ◽  
Relative Standard ◽  
Preliminary Group

The sorption of Hg (II), Cd (II), and As (III) by natural aluminosilicate is studied. It is shown that the mineral absorbs those toxicants in a rather wide pH range, quantitative extraction of analytes being achieved in a neutral or close to neutral medium (pH values range within 7.0 - 8.0; 6.3 - 7.5; 7.4 - 8.5 for Hg (II), As (III), and Cd (II), respectively). The effect of the time of phase contact on the degree of extraction of elements is shown. The sorption capacity of the mineral in optimal conditions of the medium acidity (0.06 mmol/g for mercury, 0.31 mmol/g for cadmium, and 0.52 mmol/g for arsenic) is determined. The distribution coefficients attain values of aboutnX 103-nX 104. A new combined method for determination of Hg (II), Cd (II), and As (III) in natural and waste water is developed and tested. The method consists in a preliminary group sorption concentration of the analytes by aluminosilicate, desorption of the analytes from the surface of the mineral and their subsequent atomic absorption determination. The correctness of the method is verified in analysis of spiked samples. The method is easy to use and exhibits high sensitivity, reproducibility and accuracy of analyte determination. The relative standard deviation does not exceed 0.13. Economic availability and possibility of using domestic sorption materials are the important advantages of the proposed procedure which can be used in the practice of laboratories monitoring the quality and safety of environmental objects.

ICH/FDA Guidelines-Compliant Validated Stability-Indicating HPLC-UV Method for the Determination of Axitinib in Bulk and Dosage Forms

2020 ◽  
Vol 16 (8) ◽  
pp. 1106-1112
Author(s):  
Ibrahim A. Darwish ◽  
Nasr Y. Khalil ◽  
Mohammad AlZeer
Keyword(s):  
High Performance ◽  
Kinase Inhibitor ◽  
Degradation Products ◽  
Internal Standard ◽  
Dosage Forms ◽  
Uv Detector ◽  
Stability Indicating ◽  
Therapeutic Benefits ◽  
Relative Standard

Background: Axitinib (AXT) is a member of the new generation of the kinase inhibitor indicated for the treatment of advanced renal cell carcinoma. Its therapeutic benefits depend on assuring the good-quality of its dosage forms in terms of content and stability of the pharmaceutically active ingredient. Objective: This study was devoted to the development of a simple, sensitive and accurate stabilityindicating high-performance liquid chromatographic method with ultraviolet detection (HPLC-UV) for the determination of AXT in its bulk and dosage forms. Methods: Waters HPLC system was used. The chromatographic separation of AXT, internal standard (olaparib), and degradation products were performed on the Nucleosil CN column (250 × 4.6 mm, 5 μm). The mobile phase consisted of water:acetonitrile:methanol (40:40:20, v/v/v) with a flow rate of 1 ml/min, and the UV detector was set at 225 nm. AXT was subjected to different accelerated stress conditions and the degradation products, when any, were completely resolved from the intact AXT. Results: The method was linear (r = 0.9998) in the concentration range of 5-50 μg/ml. The limits of detection and quantitation were 0.85 and 2.57 μg/ml, respectively. The accuracy of the method, measured as recovery, was in the range of 98.0-103.6% with relative standard deviations in the range of 0.06-3.43%. The results of stability testing revealed that AXT was mostly stable in neutral and oxidative conditions; however, it was unstable in alkaline and acidic conditions. The kinetics of degradation were studied, and the kinetic rate constants were determined. The proposed method was successfully applied for the determination of AXT in bulk drug and dosage forms. Conclusions: A stability-indicating HPLC-UV method was developed and validated for assessing AXT stability in its bulk and dosage forms. The method met the regulatory requirements of the International Conference on Harmonization (ICH) and the Food and Drug Administration (FDA). The results demonstrated that the method would have great value when applied in quality control and stability studies for AXT.

Development and Validation of a New Method for the Determination of Anti-hepatitis C Agent Simeprevir in Human Plasma using HPLC with Fluorescence Detection

2020 ◽  
Vol 16 (4) ◽  
pp. 428-435
Author(s):  
Ahmed F.A. Youssef ◽  
Yousry M. Issa ◽  
Kareem M. Nabil
Keyword(s):  
Hepatitis C ◽  
Human Plasma ◽  
Fluorescence Detection ◽  
Internal Standard ◽  
Protein Precipitation ◽  
Assay Method ◽  
Fluorescence Detector ◽  
Limit Of Quantification ◽  
Relative Standard

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.

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