Simultaneous determination of NNK and its seven metabolites in rabbit blood by hydrophilic interaction liquid chromatography–tandem mass spectrometry

Abstract

A hydrophilic interaction liquid chromatographic-tandem mass spectrometric (HILIC-MS-MS) method for investigation of the in vivo metabolism of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), a potent carcinogen, in rabbit blood has been developed and validated. This method achieved excellent repeatability and accuracy. Recovery ranged from 76.9 to 116.3 % and precision (as RSD) between 0.53 and 6.52 %. Linearity was good for all compounds (R(2)>0.9990) and the limit of detection (LOD) ranged from 0.016 to 0.082 ng mL(-1). Pharmacokinetic analysis indicated that NNK was rapidly eliminated in vivo in rabbit blood and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) was the major metabolite. The hydroxy acid, keto acid, and NNAL-N-oxide were also important metabolites in rabbit blood. It is probable that α-methylene hydroxylation was the major pathway of α-hydroxylation of NNK and NNAL in the rabbit.

Development of a Sensitive Method for the Determination of 4‐(Methylnitrosamino)‐1‐(3‐pyridyl)‐1‐butanol in Human Urine Using Solid‐phase Extraction Combined with Ultrasound‐assisted Dispersive Liquid–liquid Microextraction and LC‐MS/MS Detection

“…13 In this study, Oasis HLB sorbent, mixed mode cation-exchange sorbent MCX and MISPE sorbent were evaluated based on the extraction efficiency and the matrix effects on the ionization response. After SPE procedure, the residue was directly reconstituted in 200 mL of mobile phase.…”

“…The calibration curve was constructed by plotting peak area ratios (Y) of NNAL to 13 [a] Ion suppression ratio = 1-Matrix effect Fig. 2.…”

“…Especially, most Chinese smokers smoke cured cigarettes and they may have lower urinary NNAL concentration compared with those who smoke blended cigarettes, [6][7] so development of a sensitive analytical method to determinate urinary NNAL is challenging and necessary. Several analytical methods for the determination of NNAL have been reported in the literature, mainly involving gas chromatography-thermal energy analysis (GC-TEA), 8 gas chromatography-mass spectrometry (GC-MS), 9 liquid chromatography-tandem mass spectrometry (LC-MS/MS) [10][11][12][13] and capillary electrophoresis.…”

Effects of 8-methoxypsoralen on the metabolism of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone in mice

“…All mice fasted 12 h before injections. Blood samples (0.6e1.0 mL) were collected by removing their eyeballs at 5, 10, 15, 30, 45, 60, 90, 120, 180, 240 min after the injection, followed by sample treatments as described previously [18]. To determine tissue levels of NNK and its metabolites, livers and lungs were obtained immediately after blood sampling and sacrificing the mice, tissue samples prepared as described previously [17], and blood and tissue samples processed for the UPLC-MS-MS analysis.…”

“…Calibration solutions of concentrations 1, 2, 5, 10, 20, 50, 100, 200, 500, 1000 ng/mL (NNK and NNAL) and 0.5, 1, 2.5, 5, 10, 25, 50, 100, 250, 500 ng/mL (other six standards) were prepared as described previously [18]. For blood samples, calibration solutions were prepared by spiking blank plasma with the standard working solutions.…”