Abstract
Elution of polyvinylpyrrolidone (PVP) from polysulfone (PS) dialysis membrane is one of the most important problems in dialysis therapy. When dialysis treatment is started, rapid measurement of PVP eluted from the PS membrane is desirable. In this study, real-time measurement of PVP using ultraviolet spectroscopy (UV-s method) was compared with the conventional iodine coloration method (Müller method). As a result, there was a significant correlation between the UV-s and Müller methods for measuring PVP concentrations of less than 10 mg/L (r=0.970, p<0.001) and also for concentrations from 10 to 100 mg/L (r=0.993, p<0.001). The PVP concentration in PS-1.6UW dialyzer washings obtained by rinsing with 0.5 L was 2.8±2.9 mg/L by the Müller method and 3.6±2.1 mg/L by the UV-s method, while the PVP concentrations after rinsing with 1.0 L were 2.0±2.1 mg/L and 3.1±0.9 mg/L, respectively. There were no significant differences between the two methods. However, as the PVP concentration accounted for most of the dialyzer washings, the UV-s value for the PVP eluted from a dialyzer is thought to be close to the real value. It is possible to perform real-time measurement of PVP by the UV-s method and PVP eluted from a PS-1.6UW dialyzer can be measured by the UV-s method.
