AN AUTOMATED MICROMETHOD FOR THE DETERMIN ATION OF PLASMA-FREE AMINO-GROUPS USING A DISCRETE COMPUTERIZED ANALYZER

An automated method for the determination of plasma free amino groups is described. The analysis is performed on a discrete computerized ana lyzer after plasma deproteinization using trichloracetic acid. The met hod is based on the formation of a complex between terminal NH2 radica ls and 2,4,6-trinitrobenzene sulfonate (TNBS). The method is accurate (coefficient of variation = 2%), linear over a range of 0.2-7 mM/l and requires small analytic volumes; it also correlates well in the bovin e with results from standard liquid chromatography (r = 0.953). With t his method a single operator can determine free amino group contents o f 50 samples per h.