[Determination of Three Types of New Psychoactive Tryptamines in Blood by QuEChERS Combined with UPLC-MS/MS].

ABSTRACT: Objective To establish a method combining QuEChERS and ultra-high liquid chromatography-tandem mass spectrometry （UPLC-MS/MS） for rapid screening and testing of three types of new psychoactive tryptamines in human blood： 5-MeO-DALT, 5-MeO-MiPT and 5-MeO-DiPT. Methods The effects of the type of extractant, the type and dosage of salting-out agent, and the dosage of adsorbent on the test results of the three tryptamines were investigated. Blood samples were processed by QuEChERS method and then determined by UPLC-MS/MS. Results The linear relationships of 5-MeO-DALT, 5-MeO-MiPT and 5-MeO-DiPT in human blood were good in the range of 0.5-100, 0.5-100 and 0.2-100 ng/mL, respectively, with their coefficients higher than 0.99. The limits of detection （LODs） were 0.1-0.2 ng/mg. The recoveries ranged from 84.86% to 94.57%. Intra-day and inter-day precisions were good. Conclusion The method is simple, rapid, easy to operate and has a high recovery. It is suitable for the qualitative and quantitative study of tryptamines in blood and can provide the reference for public security organs to deal with related cases.

Retention Time and Ion Abundance Ratio of 8 Common Drugs （Poisons） by LC-MS/MS Qualitative Analysis.

ABSTRACT: Objective To investigate the maximum allowable deviations of retention time and ion abundance ratio of the 8 common drugs （poisons） from 3 categories, poisons （methamphetamine, morphine, ketamine）, benzodiazepines （estazolam, midazolam, diazepam, clonazepam） and barbiturates （phenobarbital） in blood, by liquid chromatography-tandem mass spectrometry （LC-MS/MS） in forensic toxicology analysis. Methods The deviations of retention time and ion abundance ratio at 7 low mass concentrations, limit of detection （LOD）, 2LOD, limit of quantitation （LOQ）, 1.5LOQ, 2LOQ, 4LOQ and 6LOQ, were tested by LC-MS/MS after liquid-liquid extraction under the conditions of two chromatographic columns and three chromatographs. Results The deviation of absolute retention time of 98.11% of 8 drugs （poisons） in the blood samples was within the range of ±0.05 min, and that of the relative retention time of 96.21% was within the range of ±0.4%. The maximum deviation of the ion abundance ratio was highly correlated with the mass concentration. When the mass concentration of drugs （poisons） was LOQ or above, more than 95% of the absolute deviation and relative deviation of the ion abundance ratio were in the range of ±25% and ±40%, respectively; when the mass concentration was below LOQ, the range could be expanded to ±35% and ±50%, respectively. Conclusion It is recommended for the determination range of the absolute retention time deviation of 8 common drugs （poisons） to be ±0.1 min and that of the relative retention time deviation to be ±1.0%. The determination range of absolute deviation of the ion abundance ratio should be ±25% when the mass concentration is LOQ or above, and the relative deviation should be ±40%. When the mass concentration is below LOQ, the deviation determination range can be expanded to ±35% and ±50%, respectively.

Ion Abundance Ratios of Qualitative Analysis by GC-MS of 4 Common Drugs （Poisons.

ABSTRACT: Objective To investigate the maximum allowable deviation of ion abundance ratios of characteristic fragment ions in common drugs （poisons） in blood by gas chromatography-mass spectrometry （GC-MS） method. Methods Four common drugs （poisons） （dichlorvos, phorate, diazepam and estazolam） were detected by GC-MS full scan mode after liquid-liquid extraction in two laboratories and under three chromatographic conditions. The deviations of ion abundance ratios of the four common drugs （poisons） in marked blood samples with concentrations of 0.5, 1.0, 2.0, 5.0 and 10.0 µg/mL were analyzed. At the same time, the false negative rates of ion abundance ratios were analyzed when the mass concentration was limit of detection （LOD）, 2LOD, limit of quantitation （LOQ） and 2LOQ, and the false positive rates of ion abundance ratios were analyzed with blank blood samples. Results Under the two laboratories, four common drugs （poisons） and three kinds of chromatography conditions, the differences in deviations of the ion abundance ratios of marked blood samples were not statistically significant （P>0.05）. More than 95% of the absolute deviations of the ion abundance ratios of the marked blood samples were within the range of ±10%, and more than 95% of the relative deviations were within the range of ±25%. In cases of low concentration （concentration less than 2LOQ） or low signal to noise ratio （3-15）, the false negative rate was less than 5% and the false positive rate was 0% when the relative deviation was greater than 50%. Conclusion The absolute deviations of ion abundance ratios of four common drugs （poisons） in marked blood samples are advised to have a determination range within ±10%, and the determination range of relative deviations within ±25%.