Open AccessRobotic Solid-Phase Extraction of Amphetamines from Urine for Analysis by Gas Chromatography-Mass Spectrometry
Author(s) -
K McCambly,
Raymond C. Kelly,
T Johnson,
James E. Johnson,
W C Brown
Publication year - 1997
Publication title -
journal of analytical toxicology.
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.161
H-Index - 76
eISSN - 1945-2403
pISSN - 0146-4760
DOI - 10.1093/jat/21.6.438
Subject(s) - chromatography , mass spectrometry , solid phase extraction , gas chromatography , chemistry , gas chromatography–mass spectrometry , urine , extraction (chemistry) , biochemistry
We have evaluated the use of the Hamilton Microlab 2200 robotic pipetting system modified to conduct solid-phase extractions of amphetamines from urine. The Hamilton system is a programmable XYZ robotic sample handling instrument compatible with commercial solid-phase extraction (SPE) columns in the most commonly available sizes. During the extraction and elution steps, the system delivers programmable positive pressure with pressure controlled feedback so as to ensure consistent recovery. The system increases sample throughput while reducing technician hands-on time and improving sample-to-sample and batch-to-batch consistency. In comparison with the manual SPE method, the automated scheme provides similar analyte recovery, accuracy, and precision and a reduced potential for laboratory errors. The method's upper limits of linearity, detection, and lquantitation were, respectively, 10,000, 100, and 100 ng/mL for amphetamine and 25,000, 50, and 50 ng/mL for methamphetamine. Extraction recoveries for the compounds ranged from 88 to 101%. Carryover amounted to less than 0.02% even at 50,000 ng/mL concentrations of analyte. A typical automated run required 20 min of technician time versus 90 min for a corresponding manual SPE procedure. The automated procedure proved to be a reliable and labor-efficient addition to the laboratory.