Pressure-adjusted continual flow heart-cutting for the high throughput determination of amphetamine-type stimulant drugs in whole blood by fast multidimensional gas chromatography-mass spectrometry

Innovative features and technical improvements in modern bench-top quadrupole gas chromatograph-mass spectrometer (GC-MS) have prepared the way for faster and more cost-effective applications while still maintaining sufficient chromatographic resolution, speed of MS data acquisition and reliability of analytical methodology. In this paper, a short wide-bore capillary column with low film thickness (5 m x 0.32 mm i.d., 0.1 microm) was used a pre-fractionating column and only chosen heart-cuts were transferred to the second chromatographic dimension (15 m x 0.25 mm i.d., 0.25 microm) by means of a pressure-adjusted continual flow type switching device for quantification of five common amphetamine-type stimulant drugs. The instrumental setting used, in combination with carefully optimized operational fast GC and MS parameters, markedly decreased the retention times of the targeted analytes, e.g., amphetamine 0.891 min and methamphetamine 1.037 min, and the total chromatographic runtime (1.700 min), as well as reducing the need for continuous cleaning of the MS ion source and increasing column life compared with conventional GC-MS approaches. The performance of the instrumental configuration and analytical method was evaluated in validation experiments and the method was also applied to authentic samples. The method demonstrates the potential of fast GC-MS in combination with a gas-phase microfluidic Deans switch device for analysing of (semi)volatile compounds, such as amphetamine-type stimulant (ATS) drugs. This should be particularly useful in modern laboratories aiming at cost-efficient analysis as well as the optimum use of available laboratory capacity and instrumentation.