Semiquantitative determination of a phenylacetic acid impurity in samples of phenylmalonic acid

1973 ◽  
Vol 7 (1) ◽  
pp. 49-50
Author(s):  
V. B. Korchagin ◽  
L. I. Serova ◽  
V. A. Volkova ◽  
N. I. Kotova ◽  
S. P. Kurakina ◽  
...  
Keyword(s):  
Phenylacetic Acid ◽  
Semiquantitative Determination ◽  
Phenylmalonic Acid ◽  
Acid Impurity

Comparison of several methods for semiquantitative determination of urinary protein.

1977 ◽  
Vol 23 (5) ◽  
pp. 876-879 ◽  
Author(s):  
W L Gyure
Keyword(s):  
Serum Albumin ◽  
Salt Concentration ◽  
Urine Samples ◽  
Urine Protein ◽  
Sulfosalicylic Acid ◽  
Green Method ◽  
Semiquantitative Determination ◽  
Acid Method ◽  
Bromcresol Green

Abstract Two types of urine protein dipsticks and the sulfosalicylic acid method were compared for their accuracy and specificity, with use of urine samples supplemented with various proteins. Dipsticks yield accurate results when the protein under consideration is restricted to albumin; the sulfosalicylic acid method accurately determines many kinds of proteins in addition to albumin. Detergents affect each of the methods, but changes in salt concentration only affect results by dipstick procedures. Dipsticks, which are based on the protein-error principle for indicators, are subject to some of the conditions that apply to the bromcresol green method for serum albumin determination.

THE IONIZATION CONSTANTS OF p-NITROPHENYLACETIC AND PHENYLMALONIC ACIDS

1933 ◽  
Vol 8 (5) ◽  
pp. 447-449 ◽  
Author(s):  
Steward Basterfield ◽  
James W. Tomecko
Keyword(s):  
Benzoic Acid ◽  
Nitro Group ◽  
Malonic Acid ◽  
Phenylacetic Acid ◽  
Ionization Constants ◽  
Side Chain ◽  
Cooh Group ◽  
Conductivity Data ◽  
Nitrobenzoic Acid ◽  
Phenylmalonic Acid

The ionization constants of p-nitrophenylacetic and phenylmalonic acids have been determined from conductivity data. The value of K for p-nitrophenylacetic acid at 25 °C. is 1.04 × 10−4, about twice that of phenylacetic acid. The nitro group in the nucleus has not as powerful an effect on the ionization when the COOH group is in the side chain as it has when both nitro group and COOH are in the nucleus. K for p-nitrobenzoic acid is six times as great as K for benzoic acid. K for phenylmalonic acid is 2. 77 × 10−3 as compared with 1.6 × 10−3 for malonic acid.

Simple semiquantitative determination of trace metal ions by use of reagent gel columns—II

Talanta ◽  
1976 ◽  
Vol 23 (3) ◽  
pp. 244-246 ◽  
Author(s):  
Yong Keun Lee ◽  
Kyu Ja Whang ◽  
Keihei Ueno
Keyword(s):  
Trace Metal ◽  
Metal Ions ◽  
Trace Metal Ions ◽  
Semiquantitative Determination

Semiquantitative determination of alkaloids by circular thin-layer chromatography

1969 ◽  
Vol 57 (3) ◽  
pp. 449-455 ◽  
Author(s):  
Manzur-ul-Haque Hashmi ◽  
Shahnaz Parveen ◽  
N. A. Chughtai
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Semiquantitative Determination ◽  
Layer Chromatography

Simple HPLC Method for Routine Determination of Urinary Phenylacetic Acid Excretion

1993 ◽  
Vol 16 (3) ◽  
pp. 733-741
Author(s):  
E. Griesemann ◽  
S. Bouquet ◽  
M. C. Perault ◽  
S. Favreliere ◽  
L. Barrier ◽  
...  
Keyword(s):  
Phenylacetic Acid ◽  
Hplc Method ◽  
Acid Excretion

Collaborative Study of a Method for the Determination of Ochratoxin A in Green Coffee

1975 ◽  
Vol 58 (2) ◽  
pp. 258-262 ◽  
Author(s):  
Colette P Levi
Keyword(s):  
Thin Layer ◽  
Ochratoxin A ◽  
Collaborative Study ◽  
Green Coffee ◽  
Average Recovery ◽  
Semiquantitative Determination ◽  
Chromatographic Methods ◽  
Green Coffee Beans ◽  
Coffee Beans

Abstract A method for the semiquantitative determination of ochratoxin A in green coffee has been studied collaboratively by 11 laboratories. The average recovery for the 7 samples spiked at 3 levels of ochratoxin A was 69.1%, ranging from 60.5 to 85.6%. This is comparable to other visual thin layer chromatographic methods of mycotoxin detection. The method has been adopted as official first action for the determination of ochratoxin A in green coffee beans.

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