Simultaneous determination of substituted diphenylamine antioxidants and benzotriazole ultra violet stabilizers in blood plasma and fish homogenates by ultra high performance liquid chromatography-electrospray tandem mass spectrometry.

Analytical methods were developed for the determination of eight substituted diphenylamines (SDPAs) and six benzotriazole UV stabilizers (BZT-UVs) in blood plasma and fish homogenate matrices. Liquid-liquid extraction by methyl tert-butyl ether and denaturation by KOH following silica gel packed column clean-up was employed for blood plasma preparation. For the fish homogenate samples, ultrasonic assisted solvent extraction combined with automated gel permeation chromatography and silica gel packed column clean-up was used. The target compounds were determined by optimized ultra performance liquid chromatography-tandem mass spectrometry in positive electrospray ionization mode. The method limits of quantification (MLOQs) of the 14 analytes ranged from 0.002 to 1.5ngg(-1) and 0.001 to 2.3ngg(-1) (wet weight, w.w.) for blood plasma and fish homogenate, respectively. The total recoveries of the target compounds varied from 61% to 100% (mean 77±9%). Eleven targets including monobutyl- (C4), dibutyl- (C4C4), monooctyl- (C8), monobutyl monooctyl- (C4C8), dioctyl-(C8C8), monononyl- (C9), dinonly-(C9C9) and 4,4'-bis(α,α-dimethylbenzyl)-(diAMS) DPAs, as well as 2-(2H-Benzotriazol-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol (UV234), 2,4-di-tert-butyl-6-(5-chloro-2H-benzotriazol-2-yl) phenol (UV327) and 2-(2H-Benzotriazol-2-yl)-4,6-di-tert-pentylphenol (UV328) were identified in the environmental biota samples, with concentrations in the range of <MLOQ-934pgg(-1), <MLOQ-4.2×10(3)pgg(-1) and <MLOQ-3.9×10(3)pgg(-1)w.w. for bottle nose dolphin (Tursiops truncatus) plasma, northern pike (Esox lucius) plasma and white sucker (Catostomus commersonii) homogenate, respectively. This is the first report of an analytical method development for SDPAs in biotic matrices and BZT-UVs in blood plasma samples.