Collaborative Study of a Chemical Method for Chick Edema Factor in Fats and Fatty Acids

1965 ◽  
Vol 48 (2) ◽  
pp. 433-437
Author(s):  
G R Higginbotham
Keyword(s):  
Fatty Acids ◽  
Chemical Method ◽  
Chromatographic Method ◽  
Collaborative Study ◽  
Edema Factor ◽  
Study Results ◽  
Gas Chromatographic Method

Abstract The microcoulometric gas chromatographic method for detection of chick edema factor in fats and fatty acids was suhjected to a second collaborative study. Results were satisfactory, and it is recommended that the method be adopted as official, first action.

Gas Chromatographic Determination of Mono- and Diglycerides in Fats and Oils: Summary of Collaborative Study

1994 ◽  
Vol 77 (3) ◽  
pp. 677-680 ◽  
Author(s):  
David Firestone
Keyword(s):  
Chromatographic Method ◽  
Collaborative Study ◽  
Fats And Oils ◽  
Chromatographic Determination ◽  
Study Results ◽  
Sunflower Oils ◽  
Aoac Method ◽  
Materials Used ◽  
Gas Chromatographic Method

Abstract A collaborative study was conducted on a capillary gas chromatographic method for the determination of mono- and diglycerides in fats and oils. Other components of fats and oils such as glycerol, fatty acids, and sterols may be analyzed by this method. Six materials used in the study consisted of 2 commercial mono- and diglyceride emulsifiers, 2 synthetic compositions with known amounts of monoand diglycerides in the presence of an excess of triglycerides, and 2 refined sunflower oils spiked with mono- and diglycerides. Eight laboratories participated in the study. On the basis of the collaborative study results, the method has been adopted first action by AOAC INTERNATIONAL as an IUPAC/AOCS/AOAC method.

Multiresidue Gas Chromatographic Method for Determining Organochlorine Pesticides in Poultry Fat: Collaborative Study

1984 ◽  
Vol 67 (2) ◽  
pp. 284-289 ◽  
Author(s):  
James A Ault ◽  
Tim E Spurgeon ◽  
◽  
M M Anderson ◽  
R Bowers ◽  
...  
Keyword(s):  
Chromatographic Method ◽  
Collaborative Study ◽  
Gel Permeation Chromatography ◽  
Accuracy And Precision ◽  
Coefficients Of Variation ◽  
Poultry Fat ◽  
Gel Permeation ◽  
Detector Method ◽  
Gas Chromatographic Method

Abstract A gas chromatographic electron capture detector method is described for the quantitative determination of organochlorine pesticide residues in poultry fat. The samples are rendered and cleaned up using automated gel permeation chromatography. The collaborative samples consisted of 10 fortified samples and one incurred residue sample, all in duplicate. Fortification levels ranged from 0.15 to 1.0 ppm for a-BHC, lindane, cis- and frans-chlordane, octachlor epoxide, o,p' and p,p'-DDT, p,p'-DDE, p,p'-TDE, hexachlorobenzene, heptachlor epoxide, dieldrin, endrin, methoxychlor, mirex, and toxaphene. The average recovery was 91.9% with a range of 81-102%. The ranges of coefficients of variation were: CVo = 3.39-14.79%; CVL = 0-16.6%; and CVx = 5.82-19.0%. The results indicate accuracy and precision comparable to other official methodology. The method has been adopted official first action.

Collaborative Study of Methods for the Analysis and Control of AG-Chlordane and Its Formulations

1973 ◽  
Vol 56 (3) ◽  
pp. 591-595
Author(s):  
Marshall A Malina
Keyword(s):  
Coefficient Of Variation ◽  
Chromatographic Method ◽  
Collaborative Study ◽  
Assay Method ◽  
Good Precision ◽  
Accuracy And Precision ◽  
Infrared Method ◽  
Gas Chromatographic Method ◽  
And Control ◽  
Excellent Accuracy

Abstract Four methods for the analysis of AG-chlordane and its formulations were submitted to a collaborative study. Fifteen laboratories, including 5 CIPAC laboratories, participated in this study. The infrared method for the analysis of the content of the 2 chlordane isomers was precise, with a coefficient of variation of 0.015. The gas chromatographic method for the analysis of the heptachlor content also yielded good precision with a standard deviation of 0.16. The infrared assay method for granular formulations exhibited excellent accuracy and precision, with a coefficient of variation of 0.067 and an error of only +0.25% relative. The gas chromatographic assay method for emulsifiable concentrates exhibited poor accuracy and precision and was found unacceptable. The first 3 methods have been adopted as official first action.

Multiresidue Gas Chromatographic Method for Determining Organochlorine Pesticides in Meats: Validation Study for Swine and Beef Fats

1985 ◽  
Vol 68 (5) ◽  
pp. 941-944
Author(s):  
James A Ault ◽  
Timothy E Spurgeon ◽  
Douglas S Gillard ◽  
Edward T Mallinson
Keyword(s):  
Organochlorine Pesticides ◽  
Validation Study ◽  
Chromatographic Method ◽  
Collaborative Study ◽  
Heptachlor Epoxide ◽  
Average Recovery ◽  
Coefficients Of Variation ◽  
Poultry Fat ◽  
Gas Chromatographic Method

Abstract A validation of a previously studied method for determining organochlorine residues in poultry fat was conducted to extend the usefulness of the method to beef and swine fats. The validation samples consisted of 16 materials all analyzed in duplicate. Fortification levels ranged from 0.02 to 1.2 ppm for a-BHC, lindane, cis- and Irans-chlordane, octachlor epoxide, o,p'- and p,p'-DDT, p,p'-DDE, p,p'-TDE, hexachlorobenzene, heptachlor epoxide, dieldrin, endrin, methoxychlor, mirex, and toxaphene. The average recovery was 101 % with a range of 7 9 - 113%, not including toxaphene. The ranges of coefficients of variation wtreCV. = 0-23.37% and CVX = 3.74-26.19%. The results were comparable to the previous collaborative study of the same method for poultry fat. The extended method has been adopted official first action

Collaborative Study of a Gas Chromatographic Method for Ronnel in Feeds

1969 ◽  
Vol 52 (3) ◽  
pp. 435-438
Author(s):  
Albert J Gehrt
Keyword(s):  
Chromatographic Method ◽  
Collaborative Study ◽  
Flame Ionization Detector ◽  
Ionization Detector ◽  
Flame Ionization ◽  
Coefficients Of Variation ◽  
Chromatographic Measurement ◽  
Cattle Feeds ◽  
Gas Chromatographic Method

Abstract A GLC method (flame ionization detector) for ronnel in cattle feeds at levels of 0.038, 0.041, and 0.055% was studied by 11 collaborators. The method involves extraction of ronnel by shaking with acetone followed by direct chromatographic measurement. The method is simple and rapid (no cleanup required), measures true ronnel, and is free from interferences present in the UV methods previously studied. Agreement between laboratories was satisfactory; coefficients of variation were 11.0, 12.0, and 7.2%. Ronnel recoveries were 81.1, 93.5, and 98.0%. Low recovery from the first sample may be due to ronnel hydrolysis or binding during storage (sample was 8 months old). The Associate Keferee recommends that the method be adopted as official first action.

Modification of the AOAC Gas-Liquid Chromatographic Method for Indole in Shrimp: Collaborative Study

1982 ◽  
Vol 65 (4) ◽  
pp. 842-845
Author(s):  
Theodore L Chambers ◽  
◽  
E C Netz ◽  
K Ogger
Keyword(s):  
Silica Gel ◽  
Chromatographic Method ◽  
Collaborative Study ◽  
Internal Standard ◽  
Current Method ◽  
Peak Height ◽  
Modified Method ◽  
Liquid Chromatographic Method ◽  
Gas Chromatographic Method ◽  
Liquid Chromatographic

Abstract Several changes were suggested for standardization of the AOAC official final action gas chromatographic method for the determination of indole in shrimp. In a collaborative study, 3 FDA laboratories compared the modified method with the current method. At a 95% confidence level, the same results were obtained for each respective sample by the AOAC or the modified method, which had the following changes. The cleanup column was standardized by drying the silica gel for 2 h at 125°C and equilibrating with 3 g of water/25 g of silica gel. Concentrated ethyl acetate shrimp extracts were treated with anhydrous sodium sulfate before column cleanup and indole was eluted from the column with 15% ethyl ether/hexane. A reduced amount of the internal standard, 2-methylindole, was used to improve peak height measurements at the 25 μg% indole level. The modified method has been adopted official first action to replace method 18.075.

Assay of NF Ethylene by Gas Chromatography

1972 ◽  
Vol 55 (5) ◽  
pp. 1067-1069
Author(s):  
N Aubrey Carson
Keyword(s):  
Atmospheric Pressure ◽  
Chromatographic Method ◽  
Collaborative Study ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Thermal Conductivity Detector ◽  
Gas Chromatograph ◽  
Gas Sampling ◽  
Gas Chromatographic Method ◽  
Standard Gas

Abstract A gas chromatographic method, utilizing a 6′ × 1/4″ Poropak R column and a thermal conductivity detector, was developed for the analysis of NF ethylene. The sample was introduced into the gas chromatograph at atmospheric pressure, using a gas sampling valve with calibrated loop. A high purity standard gas was used for comparison. With the instrument set for optimum operating conditions the precision for multiple injections of standard gas was excellent. The assay value of a sample was found to be 99.7%, when determined on 3 separate days. A collaborative study of the method is recommended.

A rapid gas chromatographic method for the quantitation of volatile fatty acids in urine

1973 ◽  
Vol 81 (1) ◽  
pp. 65-69 ◽  
Author(s):  
B.F. Gibbs ◽  
K. Itiaba ◽  
J.C. Crawhall ◽  
B.A. Cooper ◽  
O.A. Mamer
Keyword(s):  
Fatty Acids ◽  
Volatile Fatty Acids ◽  
Chromatographic Method ◽  
Gas Chromatographic Method
Sign in / Sign up

Export Citation Format

Share Document