Wimbish G H, Johnson K G
Department of Pathology, Texas College of Osteopathic Medicine, Fort Worth 76107.
J Anal Toxicol. 1990 Sep-Oct;14(5):292-5. doi: 10.1093/jat/14.5.292.
The Finnigan MAT ITS40 GC/MS permits the accurate full mass spectral identification and reproducible quantitation of 11-nor-9-carboxy-delta 9-tetrahydrocannabinol (9-carboxy-THC) in urine. Positive identification of 9-carboxy-THC is based on full mass spectral cutoff criteria whose fit value is 900. The fit value is generated from a statistically significant correlation comparison of the targeted unknown against an authentic 9-carboxy-THC standard, whose mass spectrum has been generated on the ITS40. The limit of detection (LOD) and limit of quantitation (LOQ) are 2.5 ng/mL and 5 ng/mL, respectively, using 5 mL of urine. The quantitative linear dynamic range of the assay is greater than two orders of magnitude, ranging from 5 to 1,000 ng/mL.