The analysis of mixtures of methyl ethanesulphonate and ethyl methanesulphonate by a differential reaction rate method

The Analyst ◽  
1969 ◽  
Vol 94 (1123) ◽  
pp. 909 ◽  
Author(s):  
A. J. W. Brook ◽  
K. C. Munday
Talanta ◽  
1979 ◽  
Vol 26 (6) ◽  
pp. 467-471 ◽  
Author(s):  
M.S. McCracken ◽  
H.V. Malmstadt®

1978 ◽  
Vol 50 (12) ◽  
pp. 1608-1611 ◽  
Author(s):  
Scott R. Goode ◽  
Ray J. Matthews
Keyword(s):  

1976 ◽  
Vol 22 (12) ◽  
pp. 2038-2041 ◽  
Author(s):  
T P Hadjiioannou ◽  
S I Hadjiioannou ◽  
S D Brunk ◽  
H V Malmstadt

Abstract We describe an automated enzymatic reaction-rate method for spectrophotometric determination of lactate in serum with a miniature centrifugal analyzer. The L(+)-lactate is selectively oxidized in the presence of lactate dehydrogenase (EC 1.1.1.27) and NAD+ to from NADH, whitch is measured from its absorption. Reaction rates are determined automatically, and unknown concentrations are calculated from a computer0generated calibration curve with aqueous lithium lactate standards. Lactte concentrations in the range 0.32-1.6 µg/4 µl (80-400 mg/liter) of sample were determined with relative errors and coefficient of variation of 4.8%. Analytical recovery of lactate added to pooled serum was 89-112% (average, 101%). Comparison with a kit ("Rapid Lactate") method gave a correlation coefficient squared of 0.979 over a concentration range of 39-779 mg/liter.


1979 ◽  
Vol 62 (1) ◽  
pp. 23-28
Author(s):  
Michael S Mccracken ◽  
Howard V Malmstadt

Abstract In a new automated reaction-rate method for the quantitative determination of protein nitrogen in grains and feeds, the ammonia-sodium phenate-hypochlorite reaction is used for the reaction-rate determination. After samples are digested by the official AOAC block digestion procedure, automated instrumentation is used to precisely and rapidly combine the reactants and transfer the mixed solution to an automated spectrophotometer. The rate of formation of the indophenol during 15 sec at 635 nm is automatically determined and compared with rates obtained for nitrogen standards to determine the protein nitrogen content in the sample. Relative standard deviations of about 0.6% are obtained. Results for grain and feed samples are comparable to those obtained by the official AOAC method.


Sign in / Sign up

Export Citation Format

Share Document