Introduction

Figure 1: Calibration curve of MDA data shown to be linear across two orders of magnitude; 51–5000 ng/mL. R 5 0.9995 on a linear regression with 1/x weighting.

This TurboFlow method provides better specificity for amphetamines through the duality that occurs in the TurboFlow column. The patented size exclusion properties of TurboFlow exclude the high molecular weight portion of the matrix, along with the salts, while the stationary phase coating retains the analyte(s) through the reverse-phase and anion-exchange column chemistry. This results in an on-line separation prior to an analytical separation and introduction to the mass spectrometer that is specific for amphetamines. This TurboFlow method is able to analyse for amphetamines because the turbulent flow properties successfully separate matrix interferences from amphetamines, thus enabling analysis and detection.

Instrumentation: Cohesive Aria TX-1 system
Detector: Triple quadrupole mass spectrometer
Columns: TurboFlow: Cyclone-MCX, 50µm, 0.5 × 50 mm
Analytical: Zorbax SB-Phenyl, 3.5µm, 4.6 × 75 mm

Experimental Conditions

This method describes the analysis for the determination of amphetamines from a urine sample. Human urine was used as the test matrix. A limit of quantification (LOQ) of 50 ng was seen in human urine.

Figure 2: Chromatograms showing 51 ng amphetamine, metamphetamine, MDA, MDEA, MDMA standard in urine.

Results

As seen in Figures 1 and 2.

Conclusion

Using the Cohesive Aria TX-1 system, total analysis time of the raw urine sample was 8 min per sample, including the separation of five amphetamines from urine and the analytical separation of the five analytes. When multiplexing is used, analysis time decreases to 4 min and 2 min per sample with the use of the Aria TX-2 and TX-4 respectively.