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.

scholarly journals Determination of 1,3-Dichloropropanol in Soy Sauce and Related Products by Headspace Gas Chromatography with Mass Spectrometric Detection: Interlaboratory Study

2005 ◽  
Vol 88 (5) ◽  
pp. 1404-1412 ◽  
Author(s):  
Sarah Hasnip ◽  
Colin Crews ◽  
Nicholas Potter ◽  
Paul Brereton ◽  
Henri Diserens ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Internal Standard ◽  
Mass Spectrometric ◽  
Soy Sauce ◽  
Headspace Gas Chromatography ◽  
Relative Standard ◽  
Headspace Gas

Abstract An interlaboratory study was performed to evaluate the effectiveness of a headspace gas chromatography (GC) method for the determination of 1,3-dichloro-propan-2-ol (1,3-DCP) in soy sauce and related products at levels above 5 ng/g. The test portion is mixed with an internal standard (d5-1,3-DCP) and ammonium sulfate in a sealed headspace vial. After achieving equilibrium, the headspace is sampled either by gas-tight syringe or solid-phase microextraction (SPME) and analyzed by GC with mass spectrometric detection. 1,3-DCP is detected in the selected-ion mode (monitoring m/z 79 and 81 for 1,3-DCP and m/z 82 for the deuterated internal standard) and quantified by measurement against standards. Test materials comprising soy, dark soy, mushroom soy, and teriyaki sauces, both spiked and naturally contaminated, were sent to 9 laboratories in Europe, Japan, and the United States; of these, 5 used SPME and 4 used syringe headspace analysis. Test portions were spiked at 5.0, 10.0, 20.0, 100.0, and 500.0 ng/g. The average recovery for spiked blank samples was 108% (ranging from 96–130%). Based on results for spiked samples (blind pairs at 5, 10, 20, 100, and 500 ng/g) as well as a naturally contaminated sample (split-level pair at 27 and 29 ng/g), the relative standard deviation for repeatability (RSDr) ranged from 2.9–23.2%. The relative standard deviation for reproducibility (RSDR) ranged from 20.9–35.3%, and HorRat values of between 1.0 and 1.6 were obtained.

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.

Surrogate-Assisted Determination of 2,3,7,8-Tetrachlorodibenzo-p-Dioxin in Fish by Electron Capture Capillary Gas Chromatography

1986 ◽  
Vol 69 (6) ◽  
pp. 976-980
Author(s):  
Richard A Niemann
Keyword(s):  
Gas Chromatography ◽  
Electron Capture ◽  
Capillary Gas Chromatography ◽  
Capillary Column ◽  
Electron Capture Detection ◽  
Matrix Interference ◽  
Relative Standard ◽  
Tetrachlorodibenzo P Dioxin ◽  
Liquid Chromatographic

Abstract Surrogate spiking the sample with 1000 parts per trillion (pptr) 1,3,7,8-tetrachlorodibenzo-p-dioxin (1378-TCDD) has doubled analytical throughput in determining toxic 2378-TCDD (analyte) at the low partper- trillion level in fish, using multicolumn high resolution liquid chromatographic cleanup before quantitation by capillary gas chromatography with electron capture detection. The 1378- and 2378-TCDD were recovered equally and were well separated by the capillary column so that the earlier-eluting surrogate did not interfere with the quantitation of levels of analyte many-fold lower. Matrix interference contributed <1 % bias in surrogate quantitation. Using surrogate recovery to correct for analyte losses during analysis, accuracy averaged (n = 7) 105% in determining 18 or 45 pptr 2378-TCDD added to fish without detectable bioincurred analyte. Analyses of selected fish with bioincurred 2378-TCDD gave results comparable to earlier work where recovery correction required a second analysis of sample fortified with analyte. With surrogate fortification, repeatability of determination (n = 3 or 4) improved markedly to <5% relative standard deviation at 37-46 pptr.

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 Interlaboratory study of ethanol usage as an internal standard in direct determination of volatile compounds in alcoholic products

2019 ◽  
Vol 15 ◽  
pp. 02030 ◽  
Author(s):  
S. Charapitsa ◽  
S. Sytova ◽  
A. Korban ◽  
L. Sobolenko ◽  
V. Egorov ◽  
...  
Keyword(s):  
Volatile Compounds ◽  
Volatile Component ◽  
Internal Standard ◽  
Direct Determination ◽  
Reference Method ◽  
Interlaboratory Study ◽  
Internal Standard Method ◽  
Significance Level ◽  
Standard Solutions

A collaborative interlaboratory study on the method of direct quantitation of volatile compounds in spirit drinks and alcoholic products was conducted. The discussed method applies ethanol, the major volatile component of an alcoholic product, as an internal standard. In this study 9 laboratories from 4 different countries were supplied with standard solutions for gas chromatographic measurements. Five aqueous ethanol 40% (v/v) standard solutions containing target compounds in concentrations ranging from 10 mg/L to 400 mg/L of absolute alcohol were prepared and sent to the participants for quantification of acetaldehyde, methyl acetate, ethyl acetate, methanol, 2-propanol, 1-propanol, 2-methyl-1-propanol, 1-butanol and 3-methyl-1-butanol. The interlaboratory study was evaluated according to the ISO 5725 standards and the Eurachem guide. The within-laboratory precision varied between 0.4% and 7.5% for all samples and compounds, showing a sufficiently high repeatability of the method. The between-laboratory precision was found to vary within a satisfactory range of 0.5% ÷ 10.0%. Precision of the method was well within the range predicted by the Horwitz equation for all analytes. The analysis of trueness showed that the bias of the method is insignificant at the significance level α = 5%. The determined concentrations of the analytes compared well to the gravimetrical values thus showing very satisfactory accuracy of the method. The results of the interlaboratory study confirmed that “Ethanol as Internal Standard” method is robust and reliable and can be used as a standard reference method for analysing volatile compounds in water-ethanol samples. The possibilities of method validation according to the previously obtained experimental data were shown.

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.

Gas Chromatographic Determinatiion of Monoethylene Glycol and Diethylene Glycol in Chocolate Packaged in Regenerated Cellulose Film

1988 ◽  
Vol 71 (3) ◽  
pp. 499-502
Author(s):  
Laurence Castle ◽  
Helen R Cloke ◽  
James R Startin ◽  
John Gilbert
Keyword(s):  
Gas Chromatography ◽  
Diethylene Glycol ◽  
Internal Standard ◽  
Hot Water ◽  
Gas Chromatography Mass Spectrometry ◽  
Regenerated Cellulose ◽  
Regenerated Cellulose Film ◽  
Relative Standard ◽  
Monoethylene Glycol

Abstract A method for the quantitative determination of monoethylene glycol (MEG) and diethylene glycol (DEG) in chocolate is described. The procedure involves dissolving the chocolate in hot water, defatting with hexane, removing sugars by precipitation, and analyzing as trimethylsilyl (TMS) ether derivatives by capillary gas chromatography. The use of butan-l,4-dioI as an internal standard corrects for recovery, which is between 50 and 60%, to give a relative standard deviation of 10 -11 % for the determination of both glycols at the level of 50 mg/kg. The presence of MEG and DEG in chocolate is confirmed by full scanning gas chromatography/mass spectrometry of the TMS derivatives

scholarly journals Determination of prilocaine HCl in bulk drug and pharmaceutical formulation by GC-NPD method

2013 ◽  
Vol 19 (2) ◽  
pp. 313-319 ◽  
Author(s):  
Alptug Atila ◽  
Yucel Kadioglu
Keyword(s):  
Gas Chromatography ◽  
Internal Standard ◽  
Pharmaceutical Formulation ◽  
The Novel ◽  
Relative Standard ◽  
Bulk Drug ◽  
Nitrogen Phosphorus ◽  
Percent Relative Error ◽  
Better Than

The novel analytical method was developed and validated for determination of prilocaine HCl in bulk drug and pharmaceutical formulation by gas chromatography-nitrogen phosphorus detection (GC-NPD). The chromatographic separation was performed using a HP-5MS column. The calibration curve was linear over the concentration range of 40-1000 ng ml-1 with a correlation coefficient of 0.9998. The limits of detection (LOD) and quantification (LOQ) of method were 10 ng ml-1 and 35 ng ml-1, respectively. The within-day and between-day precision, expressed as the percent relative standard deviation (RSD%) was less than 5.0%, and accuracy (percent relative error) was better than 4.0%. The developed method can be directly and easily applied for determination of prilocaine HCl in bulk drug and pharmaceutical formulation using internal standard methodology.

scholarly journals Determination of acrylamide in foods by automatic accelerated solvent extraction and gas chromatography-mass spectrometry

2020 ◽  
Author(s):  
Cuicui Kang ◽  
Haijian Ma ◽  
Yuan Li ◽  
Chizhong Zhang ◽  
Yueqin Hong ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Solvent Extraction ◽  
Internal Standard ◽  
Accelerated Solvent Extraction ◽  
Experimental Result ◽  
Gas Chromatography Mass Spectrometry ◽  
Chromatography Mass Spectrometry ◽  
Relative Standard

AbstractThe aim of the experiment is to establish a method for the determination of acrylamide in food by automatic accelerated solvent extraction-gas chromatography-mass spectrometry. D3-acrylamide was used as isotope internal standard, crushed samples were extracted and purified by automatic accelerated solvent, acrylamide was derivatized into 2,3-dibromopropanamide by potassium bromide and potassium bromate under acidic conditions, and then the derivative was extracted by ethyl acetate and detected by gas chromatography-mass spectrometry. The method had a good linear relationship in the concentration range of 10–2000 ng/mL, and the coefficient of determination (R2) was 0.9997. The detection limit of the method was 3 μg/kg. The quantification limit of the method was 10 μg/kg. The standard addition recovery of acrylamide was between 105 and 120%, and the relative standard deviation of the recovery of acrylamide was less than 3.0%. The experimental result showed that the method was simple, sensitive, efficient and accurate, and could be used for the determination of acrylamide in food.

Sign in / Sign up

Export Citation Format

Share Document