Papers by Author: Z.G. Feng

Abstract: Polyacrylamide (PAM) was usually atoxic, stable. Its hydrogel (PAMG) has been used in plastic and aesthetic surgery more than 10 years in P.R.China, Ukraine and Russia. But there were some complications with PAMG injected in patients. Considering the complicacy in vivo, it was necessary to study the PAMG’s stability. In this paper, H2O2 was added in PAMG in vitro and acrylamide (AM) content after oxidating was determined using HPLC method. Detection limit for AM can be achieved in the parts-per-billion rang. The AM content in supernatant at 0.5, 1,2 and 3 hr after oxidating of PAMG was 1.27e-8g/ml, 1.35e-8g/ml, 1.03e-7g/ml and 2.74e-7g/ml, respectively. The AM content in supernatant of PAMG was 7.70e-9g/ml. These results indicated that PAMG can be degraded to AM by hydroxyl radical. Under the same condition, the AM content was stable. So, AM can exist for a while when it was produce by degrading of PAMG. That can increase the toxicity of PAMG.

Abstract: The polyacrylamide hydrogel (PAMG) has been used in cosmetology in China, Ukraine and Russia since 1990s. Because the monomer acrylamide(AM) used to produce PAMG has been implicated as a potential mutagen and reproductive toxicant[1,2], it is important to accurately determine the amount of residual AM monomer in the PAMG. In this study, a quick, practical and simple method to determine AM is presented with respect to the hydrogel. AM is analysed quantitatively by ODS-3 column with ultraviolet (UV) absorbance detector. AM is separated from interferential component with an aqueous solution of 0.9%NaCl (NS) adjusted at pH~3.7 using hydrochloric acid and then detected at a UV wavelength of 210 nm. The results show that ODS-3 is effective approach for quantifying AM concentrations in PAMG. This method has a lower detection limit of 0.003µg/ml and a linear response range of 0.003 and 0.9 µg/ml (depending on the range required for analysis). Precision studies give coefficients of variation of <3.2%(n=5) for 0.003µg/ml. The recoveries for this method are greater than 90%. When AM content in PAMG is lower than the detection limit of this method, SPE (solid phase extraction) could be used to concentrate AM. In the case, C18 cartridge is used. And the recoveries are about 70% for SPE when AM concentration is lower than ppb.