title: Overcoming matrix effects: GC method development for the determination of triethylamine and dimethyl sulfoxide in a drug substance.
abstract: A direct injection gas chromatography method was developed for the determination of triethylamine and dimethyl sulfoxide (DMSO) in a drug substance (ML-189). Matrix effects were found to result in the overestimation of DMSO when methanol was used as diluent. Multiple approaches to eliminate matrix effects were unsuccessful; these included changes in sample size, split ratio, injector temperature and injector liner (e.g., deactivated liner). Ultimately, matrix effects were eliminated after the diluent was changed from methanol to acetone. A mechanism was proposed and discussed.
authors.affiliation: Merial Limited, Analytical R&D, 631 US Route 1 South, North Brunswick, NJ 08902.
authors.forename: Jingzhi
authors.initials: J
authors.lastname: Tian
authors.forename: Guoru
authors.initials: G
authors.lastname: Chen
authors.forename: Zhangfei
authors.initials: Z
authors.lastname: He
mesh_terms: D002626:Chemistry, Pharmaceutical; D002849:Chromatography, Gas / Q000379:methods*; D004121:Dimethyl Sulfoxide / Q000032:analysis*; D005021:Ethylamines / Q000032:analysis*; D016014:Linear Models; D004364:Pharmaceutical Preparations / Q000737:chemistry; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D005021:Ethylamines; D004364:Pharmaceutical Preparations; C016162:triethylamine; D004121:Dimethyl Sulfoxide