Monolithic silica capillary column as a new tool for extraction of methamphetamine in urine
Monolithic silica capillary column
We have established a simple screening method for methamphetamine (MA) in urine using a monolithic silica capillary column for extraction and using the Simon's reagent for colorimetric determination. Urine was mixed with borate buffer solution (50 mM, pH 10.2) and the mixture was passed through the column connected with the needle of a gas-tight syringe. MA in urine was adsorbed to the column, then eluted with 10 µl of ethyl acetate, and directly spotted on a thin-layer chromatographic plate by dividing the eluate into several aliquots. To separate MA from urine impurities and detect it clearly, a 2-µl volume of a solvent mixture (chloroform : methanol = 95 : 5, v/v, saturated with 28-0x1.fa060bfff8bbp+0mmonium hydroxide) was applied to the spot for concentrically development of the analyte.
After drying the solvent, 0.5% sodium nitroprusside solution containing 10% sodium carbonate was sprayed on the plate. The plate was put in a bottle saturated with acetaldehyde, and the ring was changed purple (Simon's reaction) when MA existed in urine. The macroscopic detection limit of MA in urine by this method was 0.5 µg/ml. To confirm efficiency of this method, the eluate from the column was analyzed by GC/MS using penta-deuterated MA as internal standard. By analysis of 30 urine samples, the results obtained by the present spot test agreed well with those by GC/MS.
Japanese journal of forensic toxicology
Japanese Association of Forensic Toxicology
(c) 2004 Japanese Association of Forensic Toxicology.