Emergency Gas—Liquid Chromatographic Determination of Barbiturates and Glutethimide in Serum

1970 ◽  
Vol 16 (7) ◽  
pp. 587-593 ◽  
Author(s):  
H E Sine ◽  
M J McKenna ◽  
T A Rejent ◽  
M H Murray
Keyword(s):  
Gas Chromatography ◽  
Clinical Evaluation ◽  
Coefficient Of Variation ◽  
Chromatographic Determination ◽  
Single Extraction ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A method is presented for the rapid gas chromatographic determination of barbiturates and glutethimide in serum, suitable for use in clinical emergencies. The sample is prepared for gas chromatography by acidification and a single extraction with chloroform. From 70 to 100% of the various barbiturates and glutethimide are analytically recovered, with a coefficient of variation of 8 to 10% for the method. During a 10-month clinical evaluation (87 requested determinations), 34 analyses (39% of the samples submitted) were positive for barbiturates, glutethimide, or both.

Liquid Chromatographic Determination of Methiocarb in Technical and Formulated Products: Collaborative Study

1984 ◽  
Vol 67 (3) ◽  
pp. 492-493
Author(s):  
Stephen C Slahck ◽  
◽  
A A Carlstrom ◽  
L T Chenery ◽  
N D Ellis ◽  
...  
Keyword(s):  
Coefficient Of Variation ◽  
Collaborative Study ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Reverse Phase ◽  
Reverse Phase Chromatography ◽  
Wettable Powder ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract An LC method for the determination of methiocarb in methiocarb technical and formulated products has been subjected to a collaborative study with 9 participating collaborators. Formulations are extracted with acetonitrile and analyzed by reverse phase chromatography, with acetophenone as an internal standard. Collaborators were furnished samples of technical, 75% wettable powder, 75% seed treater, 75% concentrate, and 50% hopper box treater. Coefficient of variation values obtained on the 5 samples were 0.71, 0.83, 0.62, 1.57, and 0.82%, respectively. The method has been adopted official first action.

High Pressure Liquid Chromatographic Determination of Monensin in Feed Premixes

1983 ◽  
Vol 66 (2) ◽  
pp. 284-286
Author(s):  
Thomas D Macy ◽  
Andrew Loh
Keyword(s):  
High Pressure ◽  
Coefficient Of Variation ◽  
Chromatographic Determination ◽  
Hplc Method ◽  
High Pressure Liquid Chromatographic ◽  
Average Recovery ◽  
Bioassay Method ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A high pressure liquid chromatographic (HPLC) method has been developed to determine monensin in feed premixes. The method is simple and rapid. Monensin is extracted with methanol-water and determined in the extracting solution by HPLC. Average recovery for monensin from a 13.2% premix sample was 103% (coefficient of variation (CV), 2.6%) by HPLC and compares with the value of 100% (CV, 3.4%) obtained by the turbidimetric bioassay method.

Direct Gas-Liquid Chromatographic Determination of Water-Soluble Vitamin K3 in Feed Premixes

1972 ◽  
Vol 55 (6) ◽  
pp. 1219-1222
Author(s):  
Victor W Winkler ◽  
John M Yoder
Keyword(s):  
Gas Chromatography ◽  
Chromatographic Analysis ◽  
Chromatographic Determination ◽  
Water Soluble ◽  
Vitamin K3 ◽  
Water Soluble Vitamin ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic ◽  
Pyrolytic Product

Abstract A method for the quantitative determination of menadione bisulfite addition products in feed premixes is presented. The menadione bisulfite compound is extracted with methanol from the premix and is determined by gas chromatography directly without pretreatment with alkali. The principle of the method is on-column pyrolysis of menadione bisulfite and subsequent gas chromatographic analysis of the pyrolytic product, menadione.

Gas-Liquid Chromatographic Determination of Acephate and Ortho 9006 Residues in Crops

1974 ◽  
Vol 57 (1) ◽  
pp. 189-191
Author(s):  
James B Leary
Keyword(s):  
Gas Chromatography ◽  
Chromatographic Method ◽  
Chromatographic Determination ◽  
Ionization Detector ◽  
Flame Ionization ◽  
Ether Solution ◽  
Liquid Chromatographic Determination ◽  
Gas Chromatographic Method ◽  
Liquid Chromatographic

Abstract A gas chromatographic method is described for determining acephate (O,S-dimethyl acetylphosphoramidothioate) and a metabolite, Ortho 9006 (O,S-dimethyl phosphoramidothioate), in a variety of crops. After extraction of the sample with ethyl acetate, the solvent is evaporated, and an ether solution of the residue is passed through a silica gel column to remove interferences. Acephate and Ortho 9006 are eluted from the column with 10% methanol in ether and measured simultaneously by programmed temperature gas chromatography, using an alkali flame ionization detector.

High-Speed Liquid Chromatographic Determination of Monensin, Narasin, and Salinomycin in Feeds, Using Post-Column Derivatization

1988 ◽  
Vol 71 (3) ◽  
pp. 480-484 ◽  
Author(s):  
Michel R Lapointe ◽  
Huguette Cohen
Keyword(s):  
Ethyl Acetate ◽  
Coefficient Of Variation ◽  
High Speed ◽  
Chromatographic Determination ◽  
Poultry Feed ◽  
Average Recovery ◽  
Animal Feeds ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A high-speed liquid chromatographic (LC) method using post-column derivatization is described for the determination of monensin, narasin, and salinomycin in a variety of animal feeds. The ionophores are extracted with hexane-ethyl acetate (90 + 10). A portion of the sample is evaporated, diluted to a known volume, and analyzed using a 6 cm 3 μm C18 column and an absorbance detector after post-column reaction with vanillin. The method has been applied to poultry and swine feeds with levels of 3-100 ppm added antibiotic. A comparison was also carried out with medicated poultry feed and beef feed lot supplement samples previously analyzed by 2 separate bioassay methods for monensin and salinomycin, respectively. Recoveries for the LC method ranged from 92.1 to 103% with an average recovery of 98.1% and a coefficient of variation of 3.65%.

Liquid Chromatographic Determination Of Polydextrose In Food Matrixes

1990 ◽  
Vol 73 (1) ◽  
pp. 51-53
Author(s):  
James B Noffsinger ◽  
Martha Emery ◽  
Daniel J Hoch ◽  
Jarmila Dokladalova
Keyword(s):  
Coefficient Of Variation ◽  
Accurate Determination ◽  
Colorimetric Method ◽  
Food Product ◽  
Chromatographic Determination ◽  
Water Soluble ◽  
Liquid Chromatographic Determination ◽  
Assay Precision ◽  
Liquid Chromatographic

Abstract A liquid chromatographic (LC) method has been developed to determine the content of polydextrose, a water-soluble 1 calorie/g bulking agent, in food matrixes such as cookies, cakes, fruit spreads, and chocolate toppings. This analysis, which requires use of a blank matrix, provides a feasible means to control the manufacture of foods containing this additive and provides a component for the accurate determination of the caloric value of a particular food product. The method involves aqueous extraction of the polydextrose from the food matrix followed by separation on a carbohydrate analysis column. The LC system uses a mobile phase of 0.005M CaS04*2H2o and a refractive index detector for quantitation. Polydextrose recoveries from the food matrixes varied from 91.5 to 100.9% with assay precision, expressed as coefficient of variation, ranging from 0.7 to 4.3%. Each error estimate was derived from 5 parallel determinations. The present methodology is precise and selective in contrast to the modified classical phenol-sulfuric acid colorimetric method for assaying carbohydrates, which had been used for polydextrose determination in food matrixes in the past. Because the coefficient of variation frequently exceeded 10%, replicate analyses were necessary to achieve quantitation.

Liquid Chromatographic Determination of Lasalocid in Premixes

1978 ◽  
Vol 61 (5) ◽  
pp. 1070-1073
Author(s):  
Robert B Hagel
Keyword(s):  
High Pressure ◽  
Coefficient Of Variation ◽  
Chromatographic Determination ◽  
Hplc Method ◽  
High Pressure Liquid Chromatographic ◽  
Insoluble Material ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A high pressure liquid chromatographic (HPLC) method has been developed to determine lasalocid in premixes. The method is simple and rapid, requiring an extraction of the drug and separation of insoluble material before HPLC. Elution times are typically <10 min per sample. The average recoveries for lasalocid at the 16.5 and 50% levels were 100.2±2 and 100.0±2%, respectively. The precision of the method (coefficient of variation = 0.02) compares favorably with that of the approved bioassay (coefficient of variation = 0.06).

Liquid Chromatographic Determination of Chlortetracycline Hydrochloride in Ruminant and Poultry/Swine Feeds

1991 ◽  
Vol 74 (5) ◽  
pp. 780-784 ◽  
Author(s):  
David C Holland ◽  
Kent C Faul ◽  
Jose E Roybal ◽  
Robert K Munns ◽  
Wilbert Shimoda
Keyword(s):  
Standard Deviation ◽  
Coefficient Of Variation ◽  
Methylene Chloride ◽  
Chromatographic Determination ◽  
Average Recovery ◽  
Liquid Chromatographic Determination ◽  
Feed Premix ◽  
Liquid Chromatographic

Abstract A liquid chromatographic (LC) method is described for the determination of chlortetracycline hydrochloride (CTC) in poultry/swine and ruminant feeds in the 10-100 ppm range and in premix. CTC is extracted from ground feed/premix with acidified acetone, and the extract is filtered through a Millex-HV filter or disposable C 18 column. The filtrate Is partitioned with methylene chloride when additional cleanup is necessary. A Nova-Pak C 18 column Is used for LC separation with determination at 370 nm. The average recovery of CTC from premix was 95% with a standard deviation (SD) of 1.70 and a coefficient of variation (CV) of 1.79%. The overall average recovery from feeds was 77% with an SO of 3.18 and a CV of 4.10%.

Determination of Thiabendazole, 5-Hydroxythiabendazole, Fenbendazole, and Oxfendazole in Milk

1990 ◽  
Vol 73 (3) ◽  
pp. 368-373 ◽  
Author(s):  
Susan S.-C Tai ◽  
Nancy Cargile ◽  
Charlie J Barnes
Keyword(s):  
Coefficient Of Variation ◽  
Chromatographic Determination ◽  
Limited Data ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract The liquid chromatographic determination previously developed for benzlmldazoles in cattle liver has been slightly modified and applied to the determination of 4 benzlmldazoles In milk. Recoveries of fenbendazole (FBZ), oxfendazole (OFZ), and thiabendazole (TBZ) from milk fortified at the 10 ppb level were 80% or greater with an Intralaboratory coefficient of variation of 11 % or less. Recovery of 5-hydroxythiabendazole (5-OH-TBZ) at the 30 ppb level averaged 56% with an Intralaboratory coefficient of variation of 5%. Limited data on the depletion of FBZ, OFZ, TBZ, and 5-OHTBZ In milk were also generated.

Gas-Liquid Chromatographic Determination of β-Asarone in Wine: Collaborative Study

1977 ◽  
Vol 60 (5) ◽  
pp. 1041-1043
Author(s):  
Randolph H Dyer
Keyword(s):  
Coefficient Of Variation ◽  
Collaborative Study ◽  
Chromatographic Determination ◽  
Repeatability Coefficient ◽  
Liquid Chromatographic Determination ◽  
The Mean ◽  
Liquid Chromatographic

Abstract The gas-liquid chromatographic determination of β-asarone (cis-2,4,5-trimethoxy-l-propenylbenzene) in wine was collaboratively studied by 9 analysts. The samples were first distilled and then extracted into hexane prior to chromatography. The mean recovery for 8 spiked samples, analyzed as blind duplicates, was 89.27%. The reproducibility coefficient of variation was 17.9%, and the repeatability coefficient of variation was 8.3%. No unfavorable remarks were noted. The method has been adopted as official first action.

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