Liquid Chromatographic Determination of Residual Reactants and Reaction By-Products in Polyethylene Terephthalate

1989 ◽  
Vol 72 (3) ◽  
pp. 468-470 ◽  
Author(s):  
Timothy H Begley ◽  
Henry C Hollifield
Keyword(s):  
Polyethylene Terephthalate ◽  
Terephthalic Acid ◽  
Chromatographic Determination ◽  
Cyclic Trimer ◽  
Food Packages ◽  
Precipitation Procedure ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic ◽  
By Products

Abstract A precipitation procedure and liquid chromatography (LC) were used to measure the residual reactants and reaction by-products in polyethylene terephthalate (PET) polymers and food packages. The polymer is dissolved in l,l,l,3,3,3-hexafluoro-2-propanol/methyIene chloride and then precipitated with acetone. The filtered solution is evaporated almost to dryness, and the concentrate is diluted with dimethylacetamide for LC analysis. Recoveries for terephthalic acid (TA), bis(2-hydroxyethyl) terephthalate (BHET), and the PET cyclic trimer averaged 95,104, and 98%, respectively. The residual levels of TA, BHET, monohydroxy ethylene terephthalic acid, and the PET cyclic trimer were measured in commercial resins and food packages.

Gas-Liquid Chromatographic Determination of Fenvalerate Insecticide Residues in Processed Apple Products and By-Products

1982 ◽  
Vol 65 (5) ◽  
pp. 1106-1111
Author(s):  
Terry D Spittler ◽  
Robert J Argauer ◽  
Donald J Lisk ◽  
Ralph O Mumma ◽  
George Winnett ◽  
...  
Keyword(s):  
Chromatographic Analysis ◽  
Chromatographic Determination ◽  
Synthetic Pyrethroid ◽  
Insecticide Residues ◽  
Apple Products ◽  
Liquid Chromatographic Analysis ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic ◽  
By Products

Abstract Apples from trees treated in the field at 2-week intervals (9 foliar applications) with the synthetic pyrethroid insecticide fenvalerate (cyano(3-phenoxyphenyL)methyl 4-chloro-alpha-(1-methylethyl)- benzeneacetate) were processed into apple sauce, juice, pomace, and peels plus cores. Gas-liquid chromatographic analysis of the commodities for fenvalerate showed the sauce and juice to be essentially residue-free, the whole apples to contain about 0.4 ppm, and the pomace and peels plus cores to contain about 2 and 1.5 ppm, respectively. Agreement among 5 laboratories using modifications of the same basic method was good.

Liquid Chromatographic Determination of Sulfasalazine in Tablets and Bulk Powder

1985 ◽  
Vol 68 (4) ◽  
pp. 803-806 ◽  
Author(s):  
Keith L Egli
Keyword(s):  
Chromatographic Determination ◽  
Reverse Phase ◽  
Commercial Sample ◽  
Bulk Powder ◽  
Liquid Chromatographic Method ◽  
Crude Product ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic ◽  
By Products

Abstract A liquid chromatographic method has been developed that determines I the amount of sulfasalazine in tablets and bulk powder in the presence of residual synthesis by-products and excipients. The method was tested j on crude product containing large amounts of impurities. A C-18 1 reverse phase column with water-acetonitrile-acetic acid mobile phase ! was found to effectively separate the drug on the column. Six different commercial samples of 500 mg tablets were assayed. The results varied from 92.6 to 101.8% of the declared amount. Spectrohotometric determinations, which do not discriminate between the drug and impurities, gave 95.4—101.8% of declared. One commercial sample of bulk powder j was assayed.

High Performance Liquid Chromatographic Determination of Intermediates and Two Reaction By-Products in FD&C Red No. 40: Collaborative Study

1981 ◽  
Vol 64 (2) ◽  
pp. 324-331
Author(s):  
Elizabeth A Cox ◽  
George F Reed ◽  
◽  
L Bille ◽  
R Bischof ◽  
...  
Keyword(s):  
High Performance ◽  
Collaborative Study ◽  
Chromatographic Determination ◽  
High Performance Liquid Chromatographic ◽  
Chromatographic Procedure ◽  
Liquid Chromatographic Determination ◽  
Repeatability And Reproducibility ◽  
Liquid Chromatographic ◽  
By Products

Abstract Nine laboratories participated in a collaborative study of an ion exchange high performance liquid chromatographic procedure for determining the intermediates and 2 reaction by-products in FD&C Red No. 40: cresidine sulfonic acid (CSA), Schaeffer’s Salt (SS), 4,4’-(diazoamino)bis(5-methoxy-2-methylbenzenesulfonic acid) (DMMA), and 6,6’-oxybis(2- naphthalenesulfonic acid) (DONS), respectively. The repeatability and reproducibility standard deviations (absolute) found in the study were 0.012 and 0.019 for CSA at the 0.2% level, 0.004 and 0.006 for DMMA at the 0.1% level, 0.067 and 0.087 for DONS at the 1% level, and 0.015 and 0.020 for SS at the 0.3% level, respectively. The method has been adopted official first action.

Simultaneous Liquid Chromatographic Determination of Selected Tricyclic Antidepressants and Co-Administered Benzodiazepines

2016 ◽  
Vol 12 (6) ◽  
pp. 560-567
Author(s):  
Marwa F. Mansour ◽  
Ehab F. El-Kady ◽  
Mona M. Abd El-Moety ◽  
Nabawia M. El-Guindi ◽  
Ann Van Schepdael ◽  
...  
Keyword(s):  
Tricyclic Antidepressants ◽  
Chromatographic Determination ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Gas-Liquid Chromatographic Determination of Technical Chlordane Residues in Food Crops: Interpretation of Analytical Data

1975 ◽  
Vol 58 (5) ◽  
pp. 1051-1061
Author(s):  
William P Cochrane ◽  
James F Lawrence ◽  
Young W Lee ◽  
Ronald B Maybury ◽  
Brian P Wilson
Keyword(s):  
Field Experiments ◽  
Stationary Phases ◽  
Analytical Data ◽  
Chromatographic Determination ◽  
Electron Capture Detection ◽  
Food Crops ◽  
Liquid Chromatographic Determination ◽  
Consistent Method ◽  
Liquid Chromatographic

Abstract An interlaboratory investigation of technical chlordane residues in food crops was carried out to determine the most practical and consistent method of reporting results. Using a technical chlordane reference standard, 8 gas chromatographic stationary phases were studied for their resolution capabilities. The best separations were obtained with SE-30 and its OV-1 equivalent. Using these columns and electron capture detection, potatoes and carrots from supervised field experiments were analyzed in duplicate and quantitated by using 4 methods of calculation. The data were statistically treated to determine the precision and bias for each method. Also, 1 sample was analyzed in duplicate on 2 different occasions by 6 laboratories to substantiate the initial conclusions. Based on the criterion of high precision it is suggested that a comparison of total area under the chromatogram of the sample with total area of a standard technical chlordane be the method of quantitation. Only peaks which are common to both standard and sample have any significance in this type of calculation.

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