RESUMO
Objective To establish a new determination method for the measuring of alkaline phosphatase activity (ALP) with p-acetyl phenyl phosphace (PAP-PNa_2) as substrate.Methods With the help of Vital semiautomatic analyzer,researched a continuous-monitoring procedure and set up experimental parameters.Results When using this assay,the wavelength of PAP's absorption was 325 nm and the Km of ALP was 0.376 mmol/L.The molecular extinction coefficient of PAP at 340 nm was 23 390 L?mol~(-1)? cm~(-1) and the concentration of citrate buffer was 0.438 mol/L.During the process,we found that the optimum pH of enzyme was 10.4,and the concentration of substrate was 5.0 mmol/L.The time of linear reaction was 900 seconds,and the linear range was 0-1 110 U/L.Serum total ALP were 63.1-118.3 U/ L(male) and 52.5-89.0 U/L(female),based on results from 60 heath adults.Conclusions The method is practical in its repetition and convenience,saves time and is not liable to be affected by bilirubin in serum.It is especially suited to the use of automatic analyzers.