Gas Chromatographic Measurement of Benzoyl Peroxide (as Benzoic Acid) in Cheese

1974 ◽  
Vol 57 (3) ◽  
pp. 706-709
Author(s):  
Albert B Karasz ◽  
Frank DeCocco ◽  
John J Maxstadt
Keyword(s):  
Gas Chromatography ◽  
Benzoic Acid ◽  
Benzoyl Peroxide ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Ether Extract ◽  
Average Recovery ◽  
Flame Ionization ◽  
Chromatographic Measurement

Abstract Benzoyl peroxide bleach, added to cheese, is estimated by gas chromatographic determination of benzoic acid, its principal reduction product. Copper is added to the acidified ether extract of the cheese to reduce the residual bleach, and solvent partitioning and permanganate treatment are used for purification. The benzoic acid is transferred to chloroform containing lauric acid as an internal standard and determined by flame ionization gas chromatography, with a column containing 5% FFAP + 0.5% H3PO4 on Chromosorb W. The average recovery of added benzoyl peroxide was 82.0% and the standard deviation was 0.0128. The occurrence of benzoic acid of microbial origin in cheese poses a problem in accurately determining added benzoyl peroxide from the benzoic acid found in a sample.

Gas Chromatographic Determination of Isofenphos in Technical and Formulated Products: Collaborative Study

1987 ◽  
Vol 70 (1) ◽  
pp. 55-57
Author(s):  
Daniel E Terry
Keyword(s):  
Thermal Conductivity ◽  
Gas Chromatography ◽  
Chromatographic Method ◽  
Collaborative Study ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Flame Ionization ◽  
Coefficients Of Variation ◽  
Gas Chromatographic Method

Abstract A gas chromatographic method for the determination of isofenphos (OFTANOL®) in isofenphos technical and liquid formulations has been developed and collaboratively studied by 11 laboratories. Two technical samples and 2 liquid flowable samples were analyzed after shaking/extracting in methanol which contained diisobutyl phthalate as an internal standard. The extracts were analyzed by gas chromatography using an SP-2100 column and either flame ionization or thermal conductivity detection. Coefficients of variation were 0.57 and 1.27% for the technical and formulated products, respectively. The GC method has been adopted official first action as a AOACCTPAC method.

Collaborative Study of the Gas Chromatographic Determination of Six Thiocarbamate Herbicides in Formulations

1974 ◽  
Vol 57 (1) ◽  
pp. 53-59
Author(s):  
James E Barney
Keyword(s):  
Gas Chromatography ◽  
Systematic Error ◽  
Coefficient Of Variation ◽  
Collaborative Study ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Flame Ionization Detector ◽  
Ionization Detector ◽  
Flame Ionization

Abstract Eptam, Ordram, Ro-Neet, Sutan, Tillam, and Vernam thiocarbamate herbicides are determined in emulsifiable and granular formulations by gas chromatography on an OV-1, SE-30, or OV-17 column with a flame ionization detector. Another thiocarbamate is used as an internal standard. The method was tested collaboratively by 19 laboratories, 18 of which tested the method on all 6 thiocarbamates. The coefficient of variation for 12 formulations was 3.10%. A significant amount of systematic error was detected, particularly in the analysis of emulsifiable formulations. The method has been adopted as official first action, and it is recommended that additional studies be conducted.

Determination of Trifluralin in Formulations by Gas Chromatography

1971 ◽  
Vol 54 (1) ◽  
pp. 125-127
Author(s):  
Larry G Hambleton
Keyword(s):  
Gas Chromatography ◽  
Chromatographic Method ◽  
Internal Standard ◽  
Flame Ionization Detector ◽  
Gas Chromatograph ◽  
Ionization Detector ◽  
Average Recovery ◽  
Flame Ionization ◽  
Gas Chromatographic Method

Abstract A gas chromatographic method has been developed that is rapid and specific for trifluralin in formulations. The sample is extracted with acetone, an internal standard is added, and the solution is diluted to volume and injected into a gas chromatograph equipped with a flame ionization detector. Three typical trifluralin formulations were analyzed by both the gas chromatographic method and an ultraviolet method. The gas chromatographic method gave an average recovery of 101.2%.

scholarly journals Gas-Chromatographic Determination of the Trimethylsilyl Derivatives of Polyhydric Alcohol Humectants in Tobacco and in Tobacco Smoke

1971 ◽  
Vol 6 (2) ◽  
Author(s):  
N. Carugno ◽  
S. Rossi ◽  
G. Lionetti
Keyword(s):  
Gas Chromatography ◽  
Mass Spectra ◽  
Triethylene Glycol ◽  
Chromatographic Determination ◽  
Flame Ionization ◽  
Trimethylsilyl Derivatives ◽  
Gas Chromatographic Method ◽  
Derivatives Of ◽  
Quantitative Procedure

AbstractA qualitative and quantitative procedure has been developed for the determination of humectants in manufactured tobacco by gas-chromatographic method with a flame ionization detector. It consists of extraction with methanol, concentration of the extract and treatment with Tri-Sil reagents. The operating gas-chromatographic conditions are set forth. Samples of tobacco containing glycerine, propylene glycol, diethylene glycol, triethylene glycol, 1-3 butylene glycol and sorbitol have been analysed with recoveries, for the first five ones, in the range of 95-104 %. In order to verify that each chromatographic peak corresponded to the relative glycol, with no interference by other silylated compounds, the mass spectra were obtained through the combination of gas-chromatography with mass spectrometry. The results achieved confirm, as far as tobacco is concerned, that the procedure is accurate and precise. The same method for the determination of humectants was extended to cigarette smoke. Even though this involves morecomplicated problems, as compared to tobacco, because of the presence of silylated compounds, it was found that, for certain glycols, the gas-chromatography of the trimethyl derivatives can be also used as a method of analysis. The mass spectra of some polyhydric alcohols are shown

Gas-chromatographic determination of cholesterol sulfate in plasma and erythrocytes, for the diagnosis of recessive X-linked ichthyosis.

1983 ◽  
Vol 29 (7) ◽  
pp. 1404-1407 ◽  
Author(s):  
F A Muskiet ◽  
G Jansen ◽  
B G Wolthers ◽  
A Marinkovic-Ilsen ◽  
P C van Voorst Vader
Keyword(s):  
Internal Standard ◽  
Dehydroepiandrosterone Sulfate ◽  
Chromatographic Determination ◽  
Anion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Single Step ◽  
Flame Ionization Detection ◽  
Cholesterol Sulfate ◽  
Flame Ionization

Abstract We describe a rapid method for determining cholesterol sulfate in plasma and erythrocytes. After its single-step isolation by means of anion-exchange chromatography cholesterol sulfate is hydrolyzed, trimethylsilylated, and determined by gas chromatography with flame ionization detection. 5 beta-Cholestan-3 alpha-ol sulfate is used as internal standard. The method enables simultaneous determination of dehydroepiandrosterone sulfate in plasma. We applied it for the diagnosis of seven patients with recessive X-linked ichthyosis. Concentrations are given for plasma and erythrocytes from four unaffected relatives of patients with X-linked ichthyosis, a patient with placental sulfatase deficiency, two patients with other types of ichthyoses, and 20 controls. The method may also be of use for the rapid isolation of other organic sulfates from biological material, as illustrated by a comparison of gas chromatograms of urine from a normal pregnant woman and that from a patient with placental sulfatase deficiency.

Capillary Gas Chromatographic Determination Of Cypermethrin In Formulations: Collaborative Study

1985 ◽  
Vol 68 (3) ◽  
pp. 592-595
Author(s):  
Peter D Bland
Keyword(s):  
Active Ingredient ◽  
Collaborative Study ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Fused Silica ◽  
Flame Ionization ◽  
Wettable Powder ◽  
Peak Areas ◽  
Liquid Concentrate

Abstract A method is described for the determination of cypermethrin, 3-(2,2- dichloroethenyl)-2,2-dimethyl-cyclopropanecarboxylate cyano-(3- phenoxyphenyl)methyl ester, in technical and formulated material by capillary gas chromatography (CGC). Samples of technical or formulated material are dissolved in CH2Cl2 containing dicyclohexyl phthalate as internal standard. The solution is injected into a gas chromatograph fitted with a flame ionization detector and capillary column of 25 m x 0.32 mm fused silica with a thick film OV-1 phase at 240°C. Injection is made into a heated injection port fitted with an antidiscrimination device in a split mode. Peak areas obtained at retention times of the internal standard and active ingredient are measured with an integrator. The quantity of cypermethrin is determined by comparing the internal standard and active ingredient peak areas with those obtained from a calibration solution containing known amounts of internal standard and pure active ingredient. Five samples were chosen for collaborative study: technical cypermethrin, 70% liquid concentrate, 3 lb/US gal. emulsifiable, 3 ib/US gal. oil concentrate, and 40% wettable powder. Twelve collaborators carried out replicate determinations on each sample on separate days. Coefficients of variation between laboratories (CVX) were 2.13 for the technical, 2.94 for the emulsifiable concentrate, 3.51 for the liquid concentrate, 2.66 for the wettable powder, and 2.29 for the oil concentrate. The method was adopted official first action.

Determination of Pyrantel in Swine Liver by Flame Ionization Gas Chromatography and Confirmation by Gas Chromatography /Mass Spectrometry

1990 ◽  
Vol 73 (6) ◽  
pp. 883-886
Author(s):  
Susan S.C Tai ◽  
Nancy Cargile ◽  
Charlie J Barnes ◽  
Philip Kijak
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Internal Standard ◽  
Gas Chromatography Mass Spectrometry ◽  
Tissue Samples ◽  
Flame Ionization ◽  
Chromatography Mass Spectrometry ◽  
Ionization Method ◽  
Swine Liver

Abstract During an evaluation of the gas chromatography/mass spectrometry (GC/MS) confirmatory procedure of Lynch and Bartoluccl for pyrantel residues in swine tissues, we developed a GC flame Ionization method for quantltatlng pyrantel residues In extracts of swine liver. The method was subjected to trial principally In the laboratories of Biospherics, Inc., using control liver, fortified control liver, and Incurred liver tissue samples. Although the method does not meet all of the current Food and Drug Administration criteria, it compares favorably to the official determinative method. Portions of the same extract can be used for quantitation and for GC/MS confirmation, true recoveries appear to be slightly higher, and an internal standard Is not required. The precision of this method equals or exceeds that of the official determinative method.

Gas-Liquid Chromatographic Determination of Tetradif on Technical and Formulations: Collaborative Study

1981 ◽  
Vol 64 (4) ◽  
pp. 829-832
Author(s):  
Bram Van Rossum ◽  
Albertus Martijn ◽  
James E Launer ◽  
◽  
E C Calamita ◽  
...  
Keyword(s):  
Collaborative Study ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Flame Ionization ◽  
Coefficients Of Variation ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract The gas-liquid chromatographic determination of tetradifon technical and formulations was collaboratively studied in duplicate with 12 laboratories. Six samples were dissolved in dichloroethane with n-hexacosane as the internal standard, chromatographed on a column of 3% SE-52, and detected by flame ionization. The average coefficients of variation were 1.2% for the 2 technical samples, 1.6% for the 2 wettable powders, and 1.5% for the 2 emulsifiable concentrates. The method has been adopted official first action.

Gas-Liquid Chromatographic Determination of Pyridazinones in Technical Products and Formulations

1978 ◽  
Vol 61 (1) ◽  
pp. 161-163
Author(s):  
Giuseppe Cellerino ◽  
Mariarosa Re
Keyword(s):  
Internal Standard ◽  
Standard Technique ◽  
Chromatographic Determination ◽  
Gas Liquid Chromatography ◽  
Flame Ionization ◽  
Selective Detector ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic ◽  
Technical Products

Abstract Simultaneous determination of the active ingredient and of by-products in technical and formulated pyridazinones was rapidly performed by gas-liquid chromatography with complete resolution of all compounds. Quantitative determination by the internal standard technique is accurate and precise. The lower limit of detectability is 8 × 10–12 g/sec with a flame ionization detector and 1 × 10–12 g/sec with a nitrogen-phosphorus selective detector operating in the nitrogen mode.

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.

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