A Rapid Method for the determination of Dehydrated alcohol (Ethanol) content in Clobetasol propionate foam by Non-polar Capillary Gas chromatography

2021 ◽  
pp. 5919-5925
Author(s):  
K.S.M.L. Sushmitha ◽  
Kumarswamy Ummiti ◽  
J.V. Shanmukha Kumar
Keyword(s):  
Gas Chromatography ◽  
Drug Product ◽  
Skin Permeation ◽  
Internal Standard ◽  
Fused Silica ◽  
Clobetasol Propionate ◽  
Chromatography Method ◽  
Droplet Shape ◽  
Ethanol Content ◽  
Pharmaceutical Aerosol

Clobeatsol propionate foam is a topical class 1 corticosteroid used to treat itching and inflammatory arthritis on the skin occurred by allergic reactions, psoriasis and eczema. In the pharmaceutical aerosol products, Dehydrated alcohol (Ethanol) is the primary ingredient and its concentration level in the formulation composition plays a significant role in the regulation of aerosol rate, droplet shape and particle size. It can also act as solubilizer for active pharmaceutical ingredient, topical disinfectant and skin permeation enhancer. Hence accurate assay of Ethanol is a crucial quality control component. A simple and rapid gas chromatography method was developed to quantify Ethanol content in Clobetasol propionate foam drug product using fused silica glass tube non-polar capillary column (HP-5, 30 m, 0.53 mm, 1.5 µm). Ethanol in the sample was diluted with methanol after adding suitable amount of internal standard, the isopropyl alcohol solution.The developed method is precise, linear and accurate in the range of 5 mg/mL to 15 mg/mL of nominal concentration of ethanol i.e. 10 mg/mL . The presented method has an advantage of a very quick gas chromatographic separation (less than 16 min) and therefore is highly suitable for in-process and stability analysis of Ethanol content in Clobetasol propionate foam drug product.

Determination of volatile alcohols and acetone in serum by non-polar capillary gas chromatography after direct sample injection.

1984 ◽  
Vol 30 (10) ◽  
pp. 1672-1674 ◽  
Author(s):  
N B Smith
Keyword(s):  
Gas Chromatography ◽  
Capillary Gas Chromatography ◽  
Capillary Column ◽  
Internal Standard ◽  
Fused Silica ◽  
Gas Chromatograph ◽  
Ionization Detector ◽  
Flame Ionization ◽  
Split Ratio

Abstract In this method for detection and quantification of volatile alcohols by capillary gas chromatography, the serum sample is deproteinized, then directly injected into the gas chromatograph with 1-propanol as the internal standard. The capillary column is a 30-m bonded methylsilicone-coated, fused-silica column. With helium as the carrier gas, the injector inlet is set at a split ratio of 1/30 and the average linear velocity in the column is 25 cm/s. Injector and flame-ionization detector temperatures are 280 degrees C, oven temperature 35 degrees C. Chromatography time is less than 3 min.

Postmortem Analysis of Benzodiazepines in Human Bone by Gas Chromatography–Mass Spectrometry

2020 ◽  
Author(s):  
Rosanna Mancini ◽  
Lucia Fernadez-Lopez ◽  
Maria Falcon ◽  
Manuela Pellegrini ◽  
Aurelio Luna ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Internal Standard ◽  
Fused Silica ◽  
Process Efficiency ◽  
Gas Chromatography Mass Spectrometry ◽  
Selected Ion Monitoring ◽  
Chromatography Mass Spectrometry ◽  
Fused Silica Capillary ◽  
Silica Capillary Column

Abstract A procedure based on gas chromatography-mass spectrometry was developed for the analysis of benzodiazepines (nordiazepam, oxazepam, lormetazepam, lorazepam, clonazepam, bromazepam and alprazolam) in postmortem human ribs. Powdered bone samples, including marrow remains inside, with the internal standard diazepam-d5 were subjected to enzymatic hydrolysis with 100 μL of β-glucoronidase and were incubated in sodium hydroxide for 1 h in a 70°C oven. Samples underwent liquid phase extraction and ethyl acetate was used as eluent. Chromatography was performed on a fused silica capillary column and the selected-ion-monitoring mode was used for analytes determination. The method was validated in the range 0.1–0.5 ng/mg (depending on the benzodiazepine) to 100 ng/mg with average values of recovery, matrix effect and process efficiency ranged from 83.2 to 94.3%, from 97.3 to 102.1% and from 80.5 to 91.2%, respectively. The intra- and inter-day accuracy was <15%. The procedure was tested in rib specimens obtained during routine autopsies from 20 cases where these benzodiazepines were found in blood. Benzodiazepines were detected in the combined bone and marrow samples in 60% of cases. Lorazepam was detected in bone in the range of 0.3–0.7 ng/mg, nordiazepam at 1.3–4.2 ng/mg and oxazepam at 1.1–1.2 ng/mg. To our knowledge, this protocol for the simultaneous analysis of these benzodiazepines is the first performed and validated using human ribs.

scholarly journals A headspace-gas chromatography method for isopropanol determination in warfarin sodium products as a measure of drug crystallinity

2018 ◽  
Vol 68 (1) ◽  
pp. 31-46 ◽  
Author(s):  
Ziyaur Rahman ◽  
Sohail Akhtar ◽  
Akhtar Siddiqui ◽  
Anthony B. Ciavarella ◽  
Agnes Nguyenpho ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Calibration Curve ◽  
Analytical Method ◽  
Drug Product ◽  
Internal Standard ◽  
Good Resolution ◽  
Headspace Gas Chromatography ◽  
Indirect Measure ◽  
Warfarin Sodium ◽  
Headspace Gas

Abstract Coumadin® a nd s everal generic products of warfarin s odium (WS) contain the crystalline form (clathrate) in which WS and isopropanol (IPA) are associated in a 2:1 molar ratio. IPA is critical in maintaining the WS crystalline structure. Physicochemical properties of the drug and drug product may change when the crystalline drug transforms to amorphous form. A headspace-gas chromatography (HS-GC) method was developed and validated for IPA determination in the WS drug product. n-propanol (NPA) was used as internal standard and the method was validated for specificity, system suitability, linearity, accuracy, precision, range, limits of detection and quantification, and robustness. The method was specific, with good resolution between IPA and NPA peaks. Chromatographic parameters (retention time, IPA/NPA area ratio, tailing factor, theoretical plates, USP symmetry, capacity factor, selectivity and resolution) were consistent over three days of validation. The analytical method was linear from 2-200 μg mL-1 (0.1- 10 % IPA present in the drug product). LOD and LOQ were 0.1 and 2 μg mL-1, respectively. Accuracy at low (2 μg mL-1) and high (200 μg mL-1) IPA concentrations of the calibration curve was 103.3-113.3 and 98.9-102.2 % of the nominal value, resp. The validated method was precise, as indicated by the RSD value of less than 2 % at three concentration levels of the calibration curve. The method reported here was utilized to determine accurately and precisely the IPA content in in-house formulations and commercial products. In summary, IPA determination by HS-GC provides an indirect measure of WS crystallinity in the drug product. Nevertheless, it should be confirmed by another analytical method since IPA from the drug substance is not distinguishable from IPA that may be present outside the drug crystals in a dosage form when prepared by wet granulation with IPA.

scholarly journals Determination of Gliclazide in Pharmaceutical Preparations by Capillary Gas Chromatography with Cool On-Column Injection and Elimination of the Matrix Effect

2001 ◽  
Vol 84 (6) ◽  
pp. 1695-1702 ◽  
Author(s):  
Jan Krzek ◽  
Janusz Czekaj ◽  
Maria Moniczewska ◽  
Włodzimierz Rzeszutko
Keyword(s):  
Gas Chromatography ◽  
Capillary Gas Chromatography ◽  
Limit Of Detection ◽  
Internal Standard ◽  
Pharmaceutical Preparations ◽  
Fused Silica ◽  
Uv Spectrophotometry ◽  
Relative Standard ◽  
Wide Range ◽  
The Matrix

Abstract Conditions were established for the identification and quantitation of gliclazide in pharmaceutical preparations by capillary gas chromatography with flame ionization detection and cool on-column injection. Gliclazide was extracted with methanol and, after filtration, assayed on a (25 m × 0.25 mm id, 0.2 μm film thickness) CP-WAX 58 (FFAP)–CB WCOT fused silica column. Because the available preparations were of various origins and, therefore, could differ in auxiliary substances and their qualitative parameters, the influence of the matrix constituents on the analytical results was taken into account. Good separation conditions were established for the developed method. The retention time of gliclazide is about 36 min and differs from the retention times of the internal standard (approximately 29 min) and additional peaks present in chromatograms (20–26 min), which were assigned to matrix constituents. The recoveries of gliclozide were high and reached 96.5%. The developed method is characterized by selectivity and precision (relative standard deviation 0.38–1.26%), a wide range of linearity (0.1–10.0 mg/mL), and a limit of detection of 30 ng. In addition, the results of chromatographic analyses calculated in 3 ways were compared with those obtained by UV spectrophotometry. The suggested technique of cool on-column injection, in contrast with split-splitless injection (used in preliminary investigations), reduces to a minimum the possibility of thermal decomposition of gliclazide.

scholarly journals Gas chromatographic determination of water and ethanol in silage by internal standard method

1982 ◽  
Vol 54 (2) ◽  
pp. 137-143
Author(s):  
Lea Huida
Keyword(s):  
Gas Chromatography ◽  
Solvent Extraction ◽  
Internal Standard ◽  
Mesh Size ◽  
Chromatographic Determination ◽  
Internal Standard Method ◽  
Oven Drying ◽  
Ethanol Content ◽  
Relative Standard ◽  
The Difference

Water and ethanol contents of different silages were determined by solvent extraction gas chromatography. Methanol was used as internal standard. The gas chromatograph was equipped with thermal conductivity and hydrogen flame ionization detectors. Glass columns, length 1.5m, i.d. 2 mm, were packed with Chromosorb 101, 80/100 mesh size. Water and ethanol extractions of 10 silages and gas chromatographic runs of the extracts could be carried out daily. The methods are suitable for routine laboratory analysis and use of the internal standard allows the gas chromatographic runs to be performed faster and more accurately. The precisions of water and ethanol determinations were satisfactory, the mean relative standard deviation percents of 12 replicate analyses being respectively 0.22 and 2.55. Water content of silages was also determined by conventional forced-air oven drying at 105°C. When ethanol content of the silage was above 5 percent, there was a tendency for water contents obtained by the oven drying method to be over 5 percentage units greater than those obtained by solvent extraction gas chromatography. When the ethanol content was below 0.5 percent, high acetic acid and lactic acid contents with low pH resulted the same tendency, the difference between the methods varring from 0.5 to 2.2 percentage units.

scholarly journals Routine analysis of plasma busulfan by gas chromatography–mass fragmentography

1998 ◽  
Vol 44 (12) ◽  
pp. 2506-2510 ◽  
Author(s):  
Wai-Kai Lai ◽  
Chi-Pui Pang ◽  
Lap-Kay Law ◽  
Raymond Wong ◽  
Chi-Kong Li ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Internal Standard ◽  
Fused Silica ◽  
Routine Analysis ◽  
Gas Chromatography Mass Spectrometry ◽  
High Dose ◽  
Mass Fragmentography ◽  
Limit Of Quantification ◽  
Time Curve ◽  
Fused Silica Capillary

Abstract Busulfan (BU) is a widely used alkylating agent for antineoplastic therapy and marrow ablation in preparation for bone marrow transplantation (BMT). High-dose BU often leads to successful preparation and low relapse but is associated with veno-occlusive disease of liver. We established a protocol to determine postdosage plasma BU concentrations by gas chromatography–mass fragmentography in an attempt to relate clinical outcome to plasma BU concentrations. We used nonisotopic pusulfan as the internal standard. After extraction into ethyl acetate, BU and pusulfan were iodinated into 1,4-diiodobutane and 1,5-diiodopentane, respectively. Gas chromatography–mass spectrometry (GC–MS) analysis was carried out on an Hewlett–Packard (HP) 5890II gas chromatograph with a 30-m 100% methyl silicon narrow bore, fused-silica capillary column interfaced with an HP 5970A mass spectrometer. Helium was the carrier gas. The sample molecules were identified by total ion monitoring and quantified by selective ion monitoring of m/z 183 and 197. The calibration curve was linear to 4 mg/L. The limit of quantification was 0.04 mg/L, and the analytical recovery was ∼97%. The within-day and between-day imprecision (CV) was <6% and 9%, respectively. In a preliminary study of 12 children, the BU areas under the BU-time curve were 616–949 μmol · min/L after the first dose and 793-1143 μmol · min/L after the fifth dose. We conclude that the GC–MS procedure is suitable for routine analysis of plasma BU.

scholarly journals Evaluation of methanol content of illegal beverages using GC and an easier modified Chromotropic acid method; a cross sectional study

2019 ◽  
Vol 14 (1) ◽  
Author(s):  
Nasim Zamani ◽  
Ali Rafizadeh ◽  
Hossein Hassanian-Moghaddam ◽  
Alireza Akhavan-Tavakoli ◽  
Mahdi Ghorbani-Samin ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Black Market ◽  
Chromotropic Acid ◽  
Alcoholic Beverages ◽  
Human Beings ◽  
Chromatography Method ◽  
Cross Sectional ◽  
Methanol Content ◽  
Acid Method ◽  
Ethanol Content

Abstract Background Methanol is highly toxic to human beings and naturally exists in some beverages. Having access to an easy and cheap method for its determination is of great importance to increase the safety of use of these beverages. Our main aim is to evaluate methanol concentration of some alcoholic beverages in Iran black market and compare it with the European and US standards. Also, we evaluated the efficacy of a newly designed and produced chemical kit in determining the risk of methanol toxicity by drinking of such samples compared to gas chromatography method. Methods Methanol content of suspected alcoholic beverages referred to forensic toxicology laboratory, Guilan province, Iran was measured using gas chromatography and a recently designed kit based on modified colorimetric chromotropic acid method. Results Of 1221 samples, 145 (11.9%) had no ethanol content, while in three samples (0.25%), methanol was high enough (700,000; 870,000; 920,000 mg/L) to cause severe methanol toxicity. Median [IQR] ethanol content of the suspected samples was 9% [3.7, 32.75]. Methanol was detected in 128 (10.48%) samples using gas chromatography method and 160 samples (13.1%) with designed kit with 100% sensitivity, 97.07% specificity, and 100% negative-predictive-value. Conclusions Alcoholic beverages produced in local black market in Iran are not safe at all. The application of the new method is practical, rapid, easy, and accurate to evaluate the risk of methanol toxicity in suspected alcoholic drinks.

scholarly journals Single gas chromatography method with nitrogen phosphorus detector for urinary cotinine determination in passive and active smokers

2010 ◽  
Vol 46 (4) ◽  
pp. 769-776 ◽  
Author(s):  
Lusiane Malafatti ◽  
Patrícia Penido Maia ◽  
Matheus Coutinho Gonçalves Martins ◽  
Maria Elisa Pereira Bastos de Siqueira ◽  
Isarita Martins
Keyword(s):  
Gas Chromatography ◽  
Internal Standard ◽  
High Concentration ◽  
Limit Of Quantification ◽  
Chromatography Method ◽  
Urinary Cotinine ◽  
Wide Range ◽  
Single Method ◽  
Nitrogen Phosphorus Detector ◽  
Nitrogen Phosphorus

Nicotine is a major addictive compound in cigarettes and is rapidly and extensively metabolized to several metabolites in humans, including urinary cotinine, considered a biomarker due to its high concentration compared to other metabolites. The aim of this study was to develop a single method for determination of urinary cotinine, in active and passive smokers, by gas chromatography with a nitrogen phosphorus detector (GC-NPD). Urine (5.0 mL) was extracted with 1.0 mL of sodium hydroxide 5 mol L-1, 5.0 mL of chloroform, and lidocaine used as the internal standard. Injection volume was 1 μL in GC-NPD. Limit of quantification was 10 ng mL-1. Linearity was evaluated in the ranges 10-1000 ng mL-1 and 500-6000 ng mL-1, with determination coefficients of 0.9986 and 0.9952, respectively. Intra- and inter-assay standard relative deviations were lower than 14.2 %, while inaccuracy (bias) was less than +11.9%. The efficiency of extraction was greater than 88.5%. Ruggedness was verified, according to Youden's test. Means of cotinine concentrations observed were 2,980 ng mL-1 for active smokers and 132 ng mL-1, for passive smokers. The results revealed that satisfactory chromatographic separation between the analyte and interferents was obtained with a ZB-1 column. This method is reliable, precise, linear and presented ruggedness in the range evaluated. The results suggest that it can be applied in routine analysis for passive and active smokers, since it is able to quantify a wide range of cotinine concentrations in urine.

scholarly journals RELATIVE APPROACH TO IDENTIFICATION OF PARAFFIN WAX ADMIXTURES IN BEE WAX

2016 ◽  
Vol 15 ◽  
pp. 262-268
Author(s):  
V. A. Rudnev ◽  
A. F. Klimchuk ◽  
L. V. Nardid
Keyword(s):  
Gas Chromatography ◽  
Internal Standard ◽  
Paraffin Wax ◽  
Chromatography Method ◽  
Modern Methods ◽  
Wax Content ◽  
The Difference

The article deals with modern methods of identifying paraffin wax admixtures in bee wax. It proves the efficiency of the approach which uses a k coefficient as a criteria to show wax content changes in the mixture with paraffin, k coefficient is a ratio of n-alkanes with even and odd number of carbon atoms. The identification of paraffin was conducted with the use of gas chromatography method without the use of an internal standard. The article considers the capacity of using this method to study paraffin - wax mixtures in a wide contents range of components. The difference in k coefficient values for the paraffin content varying from 0 to 10 % (of the mass) amounted to over 10 units. For the studied sample of pure wax the coefficient was 13.0, and for a 10 %o-admixture ofparaffin it was 2.8. The further increase in paraffin content resulted in a less intensive change of the coefficient value - up to the value of 1.5 with the paraffin content of 43 %. The identification margin in this approach can be estimated at less than 3 % of the mass.

Determination of Fatty Acid Methyl Esters in Biodiesel Catalyzed by Shell based on Gas Chromatography

2011 ◽  
Vol 347-353 ◽  
pp. 44-47 ◽  
Author(s):  
Yi Jun Zhang ◽  
Xiao Zhen Shen ◽  
Sheng Yong Liu
Keyword(s):  
Gas Chromatography ◽  
Fatty Acid ◽  
Fatty Acid Methyl Esters ◽  
Raw Materials ◽  
Methyl Esters ◽  
Acid Methyl Ester ◽  
Internal Standard ◽  
Chromatography Method ◽  
Acid Methyl ◽  
Relative Standard

In order to analyze the content of fatty acid methyl esters, biodiesel was analyzed by gas chromatography method. Biodiesel was produced from the raw materials soybean oil and mussel shell catalysts. GC analysis was developed by using HP-innowax chromatographic column and FID detector. Undecanoic acid methyl ester was chosen as internal standard solution. The results show that five kinds of fatty acid methyl esters were linear at range 4 g•L-1～31 g•L-1 (γ≥0.9928). The average recovery rate was 98.28%～101.85%, and relative standard deviation was less than 0.31%. The coefficient of variance of precision was less than 1.59%. This GC method is simple, rapid and accurate and it will be the base for further research.

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