scholarly journals Thin-layer Chromatographic Separation and Quantitative Determination of Several Free Amino-acids of Avian Liver

Nature ◽  
1963 ◽  
Vol 199 (4899) ◽  
pp. 1216-1216 ◽  
Author(s):  
ROBERT L. SQUIBB
Keyword(s):  
Amino Acids ◽  
Thin Layer ◽  
Quantitative Determination ◽  
Chromatographic Separation ◽  
Free Amino Acids ◽  
Free Amino

scholarly journals Determination of trans Vitamin K1 in Infant and Medical Nutritional Products Using AOAC Method 999.15 with Modified Preparation and Extraction Procedures and C30 Bonded Phase Chromatography: Single-Laboratory Validation

2010 ◽  
Vol 93 (2) ◽  
pp. 650-662 ◽  
Author(s):  
Karen J Schimpf ◽  
Linda B Thompson ◽  
Daniel J Schmitz
Keyword(s):  
Amino Acids ◽  
Chromatographic Separation ◽  
Free Amino Acids ◽  
Free Amino ◽  
Extraction Procedure ◽  
Vitamin K1 ◽  
Infant Formulas ◽  
Aoac Method ◽  
Single Laboratory

Abstract Modifications were made to AOAC Official MethodSM 999.15 to extend its applicability to specialty infant formulas containing hydrolyzed proteins and free amino acids, and to medical and adult nutritional products. Minor changes to the sample preparation procedure and chromatographic separation improved vitamin K1 recoveries and reduced chromatographic interferences in these types of matrixes. Currently AOAC Method 999.15 is applicable only to the determination of total vitamin K1 (phylloquione) in infant formula and milk (fluid, ready-to-feed, and powdered) containing >1 g vitamin K1/100 g solids. AOAC Method 999.15 recoveries of vitamin K1 were improved by altering sample sizes, extraction solvents and amounts, and the reagent addition order and amount of water or aqueous solutions added. The chromatographic separation of vitamin K1 in medical nutritional products containing canola and marine oils was improved, and trans vitamin K1 was separated from the biologically inactive cis isomer in all products with a C30 3 m column and a 100 methanol mobile phase. With these modifications to the extraction procedure and chromatographic separation, AOAC Method 999.15 demonstrated acceptable precision and accuracy for the quantitation of trans vitamin K1 in specialty infant formulas containing hydrolyzed proteins and free amino acids, and medical and adult nutritional products. A single-laboratory validation of these minor modifications was completed. Fourteen different product matrixes were analyzed during validation. The intermediate precision averaged 4.15 RSD (range 2.525.81 RSD), and recovery data averaged 100.1 (range 92.2109).

Quantitative determination of free amino acids with automatic amino acid analyser in liver cirrhosis blood plasma

1966 ◽  
Vol 1 (3) ◽  
pp. 75-75
Author(s):  
S. Tanaka ◽  
K. Hattori ◽  
Y. Katoo ◽  
S. Suga ◽  
A. Ishiwara ◽  
...  
Keyword(s):  
Amino Acids ◽  
Liver Cirrhosis ◽  
Amino Acid ◽  
Quantitative Determination ◽  
Blood Plasma ◽  
Free Amino Acids ◽  
Free Amino ◽  
Amino Acid Analyser

Comparison of procedures for extracting free amino acids from polymorphonuclear lekocytes.

1976 ◽  
Vol 22 (10) ◽  
pp. 1618-1622 ◽  
Author(s):  
Y Houpert ◽  
P Tarallo ◽  
G Siest
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Quantitative Determination ◽  
Free Amino Acids ◽  
Free Amino ◽  
Polymorphonuclear Leukocytes ◽  
Extraction Procedure ◽  
Intracellular Pool ◽  
Human Polymorphonuclear Leukocytes

Abstract We studies five methods for extracting amino acids from human polymorphonuclear leukocytes. Both the use of cell lysis and of a deproteinizing agent interfere with quantitative determination of the amino acids, basic amino acids being the most sensitive to the extraction procedure. Among the methods used, disruption of the cells by freezing-thawing is the best method for extracting all the amino acids. Taurine is the only amino acid extracted in the same amount by all the methods studied, and it represents half of the intracellular pool.

scholarly journals A Scheme for the Simultaneous Quantitative Determination of Free Amino Acids, Organic Non-amino Acids, Sugars, Nitrogen, and Pectic Substances in Plant Materials.

1969 ◽  
Vol 23 ◽  
pp. 999-1006 ◽  
Author(s):  
Kari Salminen ◽  
Pekka Koivistoinen ◽  
John Lemmich ◽  
Carl-Gunnar Lindblad ◽  
Alf A. Lindberg ◽  
...  
Keyword(s):  
Amino Acids ◽  
Quantitative Determination ◽  
Free Amino Acids ◽  
Free Amino ◽  
Plant Materials ◽  
Pectic Substances
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