High Pressure Liquid Chromatographic Determination of Bacitracin in Premix Feeds and Finished Feeds: Collaborative Study

1982 ◽  
Vol 65 (5) ◽  
pp. 1178-1185 ◽  
Author(s):  
John B Gallagher ◽  
Paul W Love ◽  
Linda L Knotts ◽  
◽  
M Allred ◽  
...  

Abstract A liquid chromatographic technique for the determination of bacitracin in finished feeds and premix feeds consists of an isocratic reverse phase, ion-suppressed technique. The chromatography can be completed in less than 25 min. In a collaborative study involving 9 laboratories and 3 samples of bacitracin methylene disalicylic acid and 3 samples of bacitracin zinc premixes covering the range of 10-50 g/lb, the repeatability standard deviation was 0.55, and the reproducibility standard deviation was 1.35. The average recovery of the bacitracin was 102.0%. The method has been adopted official first action for bacitracin in premix feeds.

1983 ◽  
Vol 66 (4) ◽  
pp. 864-866
Author(s):  
Eileen S Bargo ◽  
◽  
E Aranda ◽  
C Bonnin ◽  
S Hauser ◽  
...  

Abstract A reverse phase high pressure liquid chromatographic method for the determination of oxazepam in tablets and capsules was collaboratively studied by 9 laboratories. Collaborators were supplied with 6 samples that included synthetic and commercial formulations. Tablet and capsule composites are diluted with methanol and filtered. Oxazepam is determined at 254 nm by using a C18 column. Mean recoveries of oxazepam from synthetic tablet and capsule formulations were 97.2 and 99.0%, respectively. Mean coefficients of variation for tablets and capsules ranged from 1.85 to 2.86%. The method has been adopted official first action.


1982 ◽  
Vol 65 (1) ◽  
pp. 132-137
Author(s):  
Norlin W Tymes ◽  
◽  
G Briguglio ◽  
C Corcoran ◽  
R Everett ◽  
...  

Abstract Results of 11 laboratories are presented for the collaborative study of a proposed method for the quantitative reverse phase high pressure liquid chromatographic (HPLC) determination of physostigmine salicylate and physostigmine sulfate in pharmaceutical formulations. The samples consisted of commercial solution, injection, and ointment preparations, each containing one of the physostigmine salts. The physostigmine salt is extracted from ointments with acetonitrile after the ointment is dissolved in hexane. Liquid preparations are diluted directly. Physostigmine is determined at 254 nm on a C18 column by comparison with a physostigmine standard. Flurazepam hydrochloride is the internal standard. The method has been adopted official first action for the solution dosage form.


1985 ◽  
Vol 68 (3) ◽  
pp. 545-546
Author(s):  
Michael Tsougros

Abstract A stability indicating liquid chromatographic method for the determination of diazepam in tablets was collaboratively studied by 6 laboratories. The method uses a Cig reverse phase column, a methanolwater mobile phase, p-tolualdehyde as the internal standard, and photometric detection at 254 nm. The collaborators were supplied with a synthetic tablet powder and 3 commercial tablet samples. The mean recovery of diazepam from the synthetic tablet powder was 100.2%. For all samples analyzed, the coefficient of variation was < 1.5%. The method has been adopted official first action.


1984 ◽  
Vol 67 (3) ◽  
pp. 492-493
Author(s):  
Stephen C Slahck ◽  
◽  
A A Carlstrom ◽  
L T Chenery ◽  
N D Ellis ◽  
...  

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.


1986 ◽  
Vol 69 (5) ◽  
pp. 915-918
Author(s):  
Edward J Kikta ◽  
◽  
E Bane ◽  
A Burns ◽  
A Christensen ◽  
...  

Abstract A liquid chromatographic (LC) method for the analysis of technical and formulated carbofuran samples was evaluated in a collaborative study. Carbofuran is determined by reverse phase LC, using a water-methanol mobile phase and acetophenone as internal standard, and detected at 280 nm. Twelve samples, 5 formulations and technical matched pairs, were analyzed by 17 collaborating laboratories. Accuracy and variability of results are typical of large LC data sets. The method has been adopted official first action.


1980 ◽  
Vol 63 (3) ◽  
pp. 591-594
Author(s):  
Wesley R kreiser ◽  
Robert A Martin ◽  
◽  
R Bigornia ◽  
R Bond ◽  
...  

Abstract Four duplicate samples of cocoa-containing materials, a practice sample, and standards were submitted to the collaborators for theobromine and caffeine analysis by HPLC. In the method the samples are defatted with petroleum ether, and dried. The fat-free residue is then extracted with water and an aliquot is injected into the chromatograph. Compounds are quantitated by comparison with internal or external standards, either by peak height or peak area. Results for all the analyses showed that few of the values were more than 2 standard deviations from the mean. The method has been adopted as official first action.


1984 ◽  
Vol 67 (3) ◽  
pp. 497-499
Author(s):  
Stephen C Slahck ◽  
◽  
J B Audino ◽  
O O Bennett ◽  
B D Folsom ◽  
...  

Abstract A liquid chromatographic method for the determination of propoxur in technical and formulated products has been subjected to a collaborative study with 8 participating collaborators. Formulations are extracted with acetonitrile and analyzed by reverse phase chromatography, with n-butyrophenone as an internal standard. Collaborators were furnished with samples of technical, 70% wettable powder, 1.5 emulsifiable, and 2% bait. Coefficient of variation values obtained on the 4 samples were 0.34, 0.68, 3.25, and 5.41%, respectively. The method has been adopted official first action.


1978 ◽  
Vol 61 (5) ◽  
pp. 1158-1162
Author(s):  
Laurence J Helfant

Abstract The determination of bromoxynil octanoate by a gas-liquid chromatographic (GLC) method with di-n-butylphthalate as internal standard was subjected to testing by 10 collaborators. The standard deviation for bromoxynil octanoate and bromoxynil octanoate-MCPA (2-methyI- 4-chlorophenoxyacetic acid) ester formulations averaged 0.6%. While the deviation indicates that the method is statistically sound, the results were dependent upon the efficiency of the GLC column. Therefore, it is recommended that the method be subjected to continued study to further determine the GLC conditions necessary for improved method reliability.


1980 ◽  
Vol 63 (1) ◽  
pp. 91-94 ◽  
Author(s):  
William J Bachman

Abstract Reverse phase high pressure liquid chromatography (HPLC) with ion-pairing is used for the determination of pseudoephedrine hydrochloride in combination with triprolidine hydrochloride or chlorpheniramine maleate in sirups and tablets. Sirups require a preliminary column chromatography cleanup step. Response is linear for pseudoephedrine hydrochloride (range of 0–20 μg), chlorpheniramine maleate (range of 0–1.3 μg), and triprolidine hydrochloride (range of 0–1.0 μg). Recoveries from synthetic formulations were 98.8–101.3% for pseudoephedrine hydrochloride, 100.0–101.2% for chlorpheniramine maleate, and 97.7–99.8% for triprolidine hydrochloride. The coefficient of variation for the method is less than 1%.


1979 ◽  
Vol 62 (6) ◽  
pp. 1215-1219
Author(s):  
Laurence J Helfant ◽  
◽  
J Audino ◽  
G S Grimes ◽  
J J Karr ◽  
...  

Abstract The assay of bromoxynil octanoate by a gasliquid chromatographic (GLC) procedure with din-n-butylphthalate as the internal standard was previously subjected to collaboration. The method had a standard deviation of 0.6% but results varied according to the complexity of the formulaation being tested. To reduce the systematic errors of the method, the internal standard was changed to n-docosane. The change in elution time of the marker simplified the chromatogram and reduced the standard deviation of the study to 0.3%. The revised method has been adopted as official first action for determining bromoxynil octanoate.


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