Collaborative Study of a Gas Chromatographic Determination of Methylene Chloride, Ethylene Dichloride, and Trichloroethylene Residues in Spice Oleoresins

1968 ◽  
Vol 51 (4) ◽  
pp. 825-828
Author(s):  
Laura A Roberts
Keyword(s):  
Methylene Chloride ◽  
Collaborative Study ◽  
Chromatographic Determination ◽  
Chromatographic Column ◽  
Ethylene Dichloride ◽  
Gas Chromatograph ◽  
Porapak Q ◽  
Relative Retention ◽  
Solvent Residues

Abstract A method for the gas chromatographic determination of methylene chloride, ethylene dichloride, and trichloroethylene residues in spice oleoresins was studied collaboratively. The method employs a microcoulometric gas chromatograph fitted with a Porapak Q column and is based on the volatility of the solvent residues, their relative retention times on a polyaromatic bead chromatographic column, and their detectability by a halide-specific microcoulometric method. Recoveries were adequate when the method was closely followed; recoveries were erratic when collaborators deviated from the method. Further study is recommended.

Gas Chromatographic Determination of Methylene Chloride, Ethylene Dichloride, and Trichloroethylene Residues in Spice Oleoresins

1969 ◽  
Vol 52 (3) ◽  
pp. 477-481
Author(s):  
Laura A Roberts
Keyword(s):  
Chromatographic Method ◽  
Methylene Chloride ◽  
Chromatographic Determination ◽  
Ethylene Dichloride ◽  
Gas Chromatograph ◽  
Porapak Q ◽  
Relative Retention ◽  
Solvent Residues ◽  
Gas Chromatographic Method

Abstract A gas chromatographic method has been developed for determining methylene chloride, ethylene dichloride, and trichloroethylene residues in spice oleoresins. The proposed method employs a Porapak Q column and a microcoulometric gas chromatograph. It is based on the volatility of the solvent residues, their relative retention times on a polyaromatic bead chromatographic column, and their detectability using a halide-specific microcoulometric method. The system is linear for all three solvents. Six collaborators obtained recoveries ranging front 72.8 to 91.4% The lower recoveries are attributed primarily to the volatility of the solvents, delay in analysis, and titration cell disruption by solvent front. It is recommended that the method be adopted as official first action for ethylene dichloride and trichloroethylene and that methylene chloride be subjected to further study.

Gas Chromatographic Determination of Metribuzin in Formulations: Collaborative Study

1984 ◽  
Vol 67 (4) ◽  
pp. 840-843
Author(s):  
William R Betker ◽  
◽  
D Anderson ◽  
J M Bajovich ◽  
O O Bennett ◽  
...  
Keyword(s):  
Methylene Chloride ◽  
Collaborative Study ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Peak Height ◽  
Gas Chromatograph ◽  
Significant Difference ◽  
Butyl Phthalate ◽  
Gas Chromatographic Method

Abstract A collaborative study was conducted on a gas chromatographic method for determining metribuzin. Two 75% dry flow able and two 42% liquid flowable formulations were analyzed by 18 laboratories. Formulations were extracted by shaking or ultrasonic mixing for 1-5 min with methylene chloride which contained di-n-butyl phthalate as an internal standard. The extracts were injected into a gas chromatograph equipped with an OV-225 column. Peak area ratios and peak height ratios showed no significant difference. The reproducibility coefficient of variation was 0.75% for the 75% formulation and 1.41% for the 42% formulation. This GC method has been adopted official first action.

Gas Chromatographic Determination of Fensulfothion in Formulations: Collaborative Study

1986 ◽  
Vol 69 (3) ◽  
pp. 488-490
Author(s):  
William R Betker ◽  
◽  
E W Balcer ◽  
O O Bennett ◽  
W R Coffman ◽  
...  
Keyword(s):  
Chromatographic Method ◽  
Methylene Chloride ◽  
Collaborative Study ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Gas Chromatograph ◽  
Technical Product ◽  
Coefficients Of Variation ◽  
Gas Chromatographic Method

Abstract A collaborative study was conducted on a gas chromatographic method for determination of fensulfothion. Eleven laboratories analyzed 2 technical and two 6 lb/U.S. gal. spray concentrate samples. In the analysis, samples are dissolved in methylene chloride which contains 4-chlorophenyl sulfoxide as an internal standard, and solutions are injected into a gas chromatograph equipped with an OV-330 column. Withinlaboratory repeatability was 0.79% for technical product and 0.37% for the spray concentrate samples, with coefficients of variation of 0.88 and 0.58%, respectively. Among-laboratories reproducibility was 0.81% for technical product and 0.53% for the spray concentrate, with coefficients of variation of 0.91 and 0.84%, respectively. The method has been adopted official first action.

Determination of Methylene Chloride, Ethylene Dichloride, and Trichloroethylene as Solvent Residues in Spice Oleoresins, Using Vacuum Distillation and Electron Capture Gas Chromatography

1975 ◽  
Vol 58 (5) ◽  
pp. 1062-1068
Author(s):  
B Denis Page ◽  
Barry P C Kennedy
Keyword(s):  
Gas Chromatography ◽  
Electron Capture ◽  
Vacuum Distillation ◽  
Methylene Chloride ◽  
Internal Standard ◽  
Ethylene Dichloride ◽  
Porapak Q ◽  
Solvent Residues ◽  
Carrier Solvent

Abstract A quantitative gas chromatographic (GC) method is described for the determination of residual methylene chloride, ethylene dichloride, and trichloroethylene in spice oleoresins. The proposed method involves vacuum distillation in a closed system with toluene as a carrier solvent. Quantitation by electron capture GC on Porapak Q is facilitated by water extraction and by the addition of trans-l,2-dichloroethylene as an internal standard. Recoveries from oleoresins spiked at 30, 15, and 6 ppm ranged from 93 to 102%. To assess the possibility of interference from spice volatiles, the procedure was applied to 17 different spice oleoresins from 3 different manufacturers. No interferences were found, but methylene chloride levels up to 83 ppm and ethylene dichloride levels up to 23 ppm were detected. Trichloroethylene was not detected in any of the oleoresins.

Gas Chromatographic Determination of Residual Hexane in Modified Hop Extract

1972 ◽  
Vol 55 (6) ◽  
pp. 1226-1227
Author(s):  
Mark A Litchman ◽  
Lewis A Turano ◽  
Ronald P Upton
Keyword(s):  
Liquid Chromatography ◽  
Quantitative Determination ◽  
Chromatographic Determination ◽  
Methanol Solution ◽  
Chromatographic Column ◽  
Gas Liquid Chromatography ◽  
Porapak Q ◽  
Residual Hexane ◽  
Head Space

Abstract A method is described for the quantitative determination of hexane in modified hop extract by head-space gas-liquid chromatography. A sample of extract is weighed into a serum vial and water-methanol solution is added. The vial is sealed tightly and heated 1 hr in a 70°C bath. A sample of the head-space gas over the solution is injected onto a Porapak Q gas chromatographic column for determination. Recovery of 2–29 ppm hexane added to potassium isohumulone was 95.5–114.8%. The method may be applicable to other hop extracts.

scholarly journals Gas Chromatographic Determination of Alachlor in Microencapsulated Formulations: Mini-Collaborative Study

1987 ◽  
Vol 70 (6) ◽  
pp. 1056-1058
Author(s):  
David F Tomkins
Keyword(s):  
Coefficient Of Variation ◽  
Chromatographic Method ◽  
Collaborative Study ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Chromatographic Column ◽  
Data Points ◽  
Gas Chromatographic Method ◽  
Isothermal Gas

Abstract An isothermal gas chromatographic method for measuring alachlor in Micro-Tech® (microencapsulated) formulations was tested by 5 collaborators. The samples were prepared in acetone, and alachlor was determined using a gas chromatographic column of 10% SP- 2250 on 100-120 mesh Supelcoport. Di-n-pentylphthalate was used as the internal standard. Collaborators made single determinations on 5 samples distributed as blind duplicates. The mini-collaborative study generated 47 data points. The coefficient of variation (CV„- pooled) was 1.35%, and CVx-pooled was 0.73%. The method was simple to use and did not reveal any interferences in samples tested. The method has been adopted official first action as an AOACCIPAC method.

Liquid Chromatographic Determination and Identification Tests for Dexamethasone in Bulk Drugs and Elixirs: Collaborative Study

1987 ◽  
Vol 70 (6) ◽  
pp. 967-973
Author(s):  
Elaine A Bunch
Keyword(s):  
Methylene Chloride ◽  
Collaborative Study ◽  
Internal Standard ◽  
Dosage Level ◽  
Chromatographic Determination ◽  
Photometric Detection ◽  
Coefficients Of Variation ◽  
Bulk Drug ◽  
Liquid Chromatographic

Abstract A normal phase liquid chromatographic method for the determination of dexamethasone in bulk drugs and elixirs was collaboratively studied by 6 laboratories. The method uses a silica column, water-modified acetic acid-methanol-methylene chloride mobile phase, cortisone internal standard, and photometric detection at 254 nm. Collaborators were supplied blind duplicate samples of 3 bulk drugs, 2 commercial elixirs, and 1 authentic elixir. Dexamethasone elixir dosage level is 0.5 mg/5 tnL. Mean recovery of dexamethasone from the authentic elixir formulated to contain 0.471 mg/5 mL was 94.5%. (Authentic elixirs were found to stabilize about 6% below the theoretical concentration.) Mean recovery for the bulk drugs was between 97.1 and 100.1%. Mean coefficients of variation for bulk drug and elixir samples were less than 0.8% and 3.6%, respectively. Identification tests for dexamethasone by thin-layer chromatography, infrared spectroscopy, and relative LC retention times, as well as the gas chromatographic determination of alcohol in the elixirs were also collaboratively studied. Mean recovery of alcohol from the synthetic elixir was 98.6%. The mean coefficient of variation for alcohol for all samples analyzed was less than 1.4%. The LC method for dexamethasone in drug substance and elixirs, the identification tests, and the GC method for alcohol in dexamethasone elixirs have been adopted official first action.

Gas Chromatographic Determination of Chlordimeform in Pesticide Formulations: Collaborative Study

1985 ◽  
Vol 68 (3) ◽  
pp. 589-592
Author(s):  
Thomas G Gale ◽  
Arthur H Hofberg
Keyword(s):  
Active Ingredient ◽  
Methylene Chloride ◽  
Collaborative Study ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Matched Pair ◽  
Flame Ionization ◽  
Pesticide Formulations ◽  
Better Than

Abstract Agaschromatographic (GC) procedure for the determination of chlordimeform in emulsiflable concentrate formulations containing about 46% active ingredient was collaboratively studied using the matched pair scheme. Chlordimeform was extracted from the formulation with methylene chloride containing diethyl terephthalate as the internal standard, chromatographed on CBWX-20M, and detected by flame ionization. Determinations on the 4 samples by 20 government, university, and industrial collaborators using peak area measurements showed within-laboratory repeatability of better than 1%. Reproducibility was 1.2% for the formulation. The method has been adopted official first action.

Improved Multiresidue Gas Chromatographic Determination of Organophosphorus, Organonitrogen, and Organohalogen Pesticides in Produce, Using Flame Photometric and Electrolytic Conductivity Detectors

1981 ◽  
Vol 64 (5) ◽  
pp. 1187-1195 ◽  
Author(s):  
Milton A Luke ◽  
Jerry E Froberg ◽  
Gregory M Doose ◽  
Herbert T Masumoto
Keyword(s):  
Petroleum Ether ◽  
Methylene Chloride ◽  
Organophosphorus Pesticides ◽  
Chromatographic Determination ◽  
Electrolytic Conductivity ◽  
Gas Chromatograph ◽  
Flame Photometric Detector ◽  
Initial Concentration ◽  
Photometric Detector

Abstract The multiresidue procedure of Luke et al., which uses extraction with acetone and partition with petroleum ether and methylene chloride, was simplified and shortened by eliminating the Florisil cleanup. Double concentration with petroleum ether in the Kuderna-Danish evaporator following the initial concentration removed the last traces of methylene chloride. The extract was then injected into a gas chromatograph, using a Hall electrolytic conductivity detector for organohalogen, organonitrogen, and organosulfur pesticides or a flame photometric detector for organophosphorus pesticides. Recoveries of 79 pesticides are presented.

Gas-Liquid Chromatographic Determination of Benzoic Acid and Sorbic Acid in Foods: NMKL1 Collaborative Study

1983 ◽  
Vol 66 (3) ◽  
pp. 775-780
Author(s):  
Bonny K Larsson ◽  
◽  
M Askeland ◽  
M Bergstrøm-Nilsen ◽  
H K Dahle ◽  
...  
Keyword(s):  
Benzoic Acid ◽  
Apple Juice ◽  
Methylene Chloride ◽  
Sorbic Acid ◽  
Collaborative Study ◽  
Chromatographic Determination ◽  
Caproic Acid ◽  
Coefficients Of Variation ◽  
Liquid Chromatographic

Abstract A gas-liquid chromatographic method for the simultaneous determination of benzoic acid and sorbic acid in foods was collaboratively studied by 8 laboratories. Benzoic and sorbic acids are isolated from food by successive extractions with ether, sodium hydroxide, and methylene chloride, converted to trimethylsilyl (TMS) esters, and determined by gasliquid chromatography. Phenylacetic acid and caproic acid are used as internal standards for benzoic acid and sorbic acid, respectively. Seven samples were collaboratively studied: almond paste, fish homogenate, and apple juice with benzoic and sorbic acid levels from 0.04 to 2 g/kg. Average recoveries {%) for benzoic and sorbic acids were as follows: almond paste, 99.6 and 101.2; fish homogenate, 99.2 and 97.4; and apple juice 98.2 and 106.6. The reproducibility coefficients of variation (%) for benzoic and sorbic acids at 0.5-2 g/kg levels were 3.5-6.1 and 5.2-9.0; and at the 0.04 g/kg level, 14.7 and 23.3, respectively. The method has been adopted official first action at 0.5-2 g/kg levels.

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