6533b85ffe1ef96bd12c2589

RESEARCH PRODUCT

Chemical transformations of glucose in solutions for peritoneal dialysis after sterilization and during storage

subject

description

The objective of this work was to estimate glucose degradation products (GDPs) in solutions for peritoneal dialysis (PD) including glucose and sodium lactate based on the change of pH and absorption of ultraviolet (UV) light. Spectrophotometric and pH-metric methods were used to measure glucose degradation and transformation of GDPs in laboratory-made solutions after heat sterilization and during storage. Mechanism of transformations of GDPs in the sterilized solutions for PD during storage and spectral characteristic of 5-HMF were studied. Common features for all the batches of the tested solutions for PD after heat sterilization were a reduce in pH, increase in the absorbance in the range of 200 to 350 nm and the appearance of λmax at 274-283 nm. This indicated that 3,4-dideoxyglucosone-3-ene (3,4-DGE) and 5-hydroxymethylfurfural (5-HMF) had been formed during heat sterilization. Hypsochromic shift relative to 5-HMF was explained by a spectral interference of levulinic acid having λmax at 266 nm. The change of pH after sterilization depended on the initial pH (before sterilization) and glucose concentration. During storage at room temperature hypsochromic or slight batochromic shift was observed. The absorbance at 228-230 nm diminished while that at λmax (270.5-280 nm) was slightly reduced or even increased depending on the composition of a solution and time of storage. It was established that 5-HMF had two absorption maxima at the wavelengths of 228-229 and 283-284 nm in the water medium and the absorbance of 5-HMF at 284 nm followed Beerís law very well in the range of concentrations of 1.97 to 9.85 mg/L.