Beckman-Spinco amino acid analyzer

Salt-free trypsin (Worthington Biochemical Corporation Lot No. 688SF) unoxidized, and oxidized as described in the text, were hydrolyzed by constant-boiling hydrochloric acid for 20 hr at 105°C. Except for the oxidation step, the samples were treated identically. The oxidized sample posse.ssed 3% of the original activity. The hydrolyzates were analyzed for amino acids using the Automatic Amino Acid Analyzer (Beckman-Spinco) developed by Spaokman et al. (1958). Ninety-nine and 97% of the applied nitrogen was recovered in the case of unoxidized and oxidized trypsin hydrolyzates respectively. 

Recently, I have been doing some preliminary investigations of the alloisoleucine/isoleucine ratio in a sample taken from a depth of 2500 meters in the Atlantic Ocean. After isolating the amino acids by a procedure similar to that used by Chau and Riley (2), the sample was analyzed for the presence of alloisoleucine on the Beckman-Spinco automatic amino acid analyzer. The results indicate that a small amount of alloisoleucine appears to be present in the sample. It is impossible to make any conclusions from this one experiment, however, since the analysis of a blank which had been carried through the same isolation steps as the sea water sample contained a significant amount of isoleucine. Also, several dipeptides appear at about the same location as does alloisoleucine on the chromatogram from the automatic amino acid analyzer. Many samples from the worlds oceans will have to be analyzed before it can be determined whether the racemization of amino acids can be used to calculate amino acid residence times in the sea. 

Ion-exchange chromatogram from Beckman-Spinco model 121MB amino acid analyzer introduced in 1969. After separation, amino acids were derivatized with ninhydrin to form colored products detected by visible absorption. [Courtesy Beckman-Coulter, Fullerton CA.1... 

The acid hydrolyzate (6 N HCl, 100 °C, 48 h) of clupeine Z was analyzed in a Beckman/ Spinco automatic amino-acid analyzer. Since these values were calculated from the data in mole percentage, the value for recovery is not shown. 

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See also in sourсe #XX -- [ ]

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