[Polarimetric determination of alpha-amylase activity (author's transl)].

In the study of the relatively slow amylase-catalysed hydrolysis of oligosaccharides, it is assumed that the subsequent mutarotation has essentially no effect on the kinetics of the total reaction. Relatively large sampled and long measurement times (slow rate of change in angle of rotation) are necessary for the polarimetric determination of alpha-amylase activity. For these reasons, only urine and duodenal juice are suitable as sample sources. Owing to the absence of coupled reactions and auxilliary enzymes, the polarimetrically determined kinetics are generally more representative of the true kinetics of the amylase reaction, than those obtained with fully enzymic methods; in addition, single determinations by the polarimetric method are less subject to interference by sample components. With measurement times in the order of minutes, the polarimetric method shows excellent linearity, very good proportionality between analytical response and quantity of enzyme, and good precision in series (CV = 1.3%). Comparison of the polarimetric with a chromogenic and a fully enzymic method showed an acceptable correlation (r for each method was about 0.98). T, the polarimetric method shows excellent linearity, very good proportionality between analytical response and quantity of enzyme, and good precision in series (CV = 1.3%). Comparison of the polarimetric with a chromogenic and a fully enzymic method showed an acceptable correlation (r for each method was about 0.98). T, the polarimetric method shows excellent linearity, very good proportionality between analytical response and quantity of enzyme, and good precision in series (CV = 1.3%). Comparison of the polarimetric with a chromogenic and a fully enzymic method showed an acceptable correlation (r for each method was about 0.98). The advantages and disadvantages of the polarimeatric method, with consideration of possible interfering factors, are discussed.