A retention index library for commonly encountered drugs and metabolites using tri-n-alkylamines as reference compounds, nitrogen-phosphorus detectors, and dual capillary chromatography.
The retention index system is a reproducible means for the identification of drugs in toxicology samples analyzed by gas chromatography with flame ionization detectors. Nitrogen-phosphorus (NP) detectors do not respond well to the standard n-alkanes, which lack nitrogen and phosphorus groups and which are used to obtain the Kovats index. A method is presented that creates a retention index library based upon a homologous series of tri-n-alkylamines for a series of 125 drugs and metabolites. Standards were analyzed under temperature programmed conditions by simultaneous dual column chromatography using a 5% phenyl and a 50% phenyl methyl silicone fused-silica capillary column. By increasing the hydrogen and air flows to the NP detectors, the Kovats indices were calculated on the system using the n-alkanes C8 through C32. Tri-n-alkylamine indices calculated under the same conditions were compared to the Kovats indices for 14 drugs on the 5% phenyl column and for 12 drugs on the 50% phenyl column. The correlation was found to be linear. The Kovats indices on the 5% phenyl column were compared to previously reported values and found to be consistent.
Watts
V W
VW
Mesa Police Department Crime Laboratory, Arizona 85201-6697.
Simonick
T F
TF
D000588:Amines / Q000592:standards*; D002849:Chromatography, Gas / Q000379:methods*; D005410:Flame Ionization / Q000379:methods*; D006801:Humans; D009584:Nitrogen / Q000032:analysis; D004364:Pharmaceutical Preparations / Q000302:isolation & purification / Q000592:standards*; D010758:Phosphorus / Q000032:analysis; D012015:Reference Standards; D014116:Toxicology
D000588:Amines; D004364:Pharmaceutical Preparations; D010758:Phosphorus; D009584:Nitrogen