Quality Evaluation Of Chloroprene Production And Analysis Of Dha In Blood

The quality evaluation method of chloroprene and the analysis method with gas chromatography (GC) for DHA content in blood based on the HCl-CH3OH esterification and2-amino-2-methylpropanol (AMP) derivatization are established.Chloroprene is active with various reactions such as addition, oxidation and polymerization, and in the meantime impurities introduced in industrial production significantly affects its polymerization, making it urgent to develop advanced quality evaluation protocol for chloroprene production. The first part of this research studied the quantitative analysis of peroxides, iron and polymerization inhibitors and the qualitative analysis of impurities as well in chloroprene production.The method was modified to analyze peroxides by1,10-phenanthroline spectrophotometric method, and the average recovery of peroxides was103.6%, with RSD (residual standard deviation) of2.88%, which can overcome the drawback of poor reproducibility of the titration analysis that is applied in the industry. Furthermore, this analytical method was established to detect iron during chloroprene production. The external standard method was developed for the GC analysis of polymerization inhibitors, with a detection limit of1.0μg/mL, more sensitive and accurate than that of the colorimetric analysis. Moreover,11impurities, including5compounds such as dichloroethylene and chlorobutylene not detected before, were analyzed and identified by the GC-MS technology.The brain and intelligence development of the premature infants might be affected by the deficiency of DHA. A simple, rapid and accurate detection of DHA in blood without doubt benefits early treatment of diseases related to this symptom, and formulating balanced nourishment. In the second part of this research, two protocols:GC analysis based on the esterification of DHA with CH3OH catalyzed by HCl and the derivatization of DHA by AMP were developed.The optimal reaction conditions for the esterification and derivatization reactions were explored. The sample was reacted with2mL of1.3mol HCl in CH3OH solution at60℃for60min or2mL of AMP at170℃for90min, and then subjected to the GC-MS analysis with tricosane acid as the internal standard. The regressive equations were obtained:y=0.0112x-0.0070(R2=0.9997) for the esterification treatment, and y=0.0095x-0.0042(R2 =0.9997) for the AMP derivatization, with a linear range of0-100μg/mL DHA. The recoveries of DHA were80.67～109.75%and97.67～115.5%, respectively. More than150blood samples of premature infants were analyzed by esterification method. Meanwhile, the two analytical protocols were reproducible with the analysis, but the AMP derivatization treatment is fast and simple.