Sample flunitrazepam

Macek et al. [120] developed a method to quantitate omeprazole in human plasma using liquid chromatography-tandem mass spectrometry. The method is based on the protein precipitation with acetonitrile and a reversed-phase liquid chromatography performed on an octadecylsilica column (55 x 2 mm, 3 /im). The mobile phase consisted of methanol-10 mM ammonium acetate (60 40). Omeprazole and the internal standard, flunitra-zepam, elute at 0.80 0.1 min with a total rim time 1.35 min. Quantification was through positive-ion made and selected reaction monitoring mode at m/z 346.1 —> 197.9 for omeprazole and m/z 314 —> 268 for flunitrazepam, respectively. The lower limit of quantification was 1.2 ng/ml using 0.25 ml of plasma and linearity was observed from 1.2 to 1200 ng/ml. The method was applied to the analysis of samples from a pharmacokinetic study. 

More recently Wang et al. have proposed analytical methods involving the use of UHPLC-MS/MS to determine four opiates and metabolites, live amphetamines, flunitrazepam and its two metabolites, cocaine and its four metabolites in OF. Samples were collected by spitting in a tube, then the fluids were diluted with twice the amount of distilled and deionized water and vortexed for 30 s. Liquid chromatography was performed with a gradient elution and the total run time was 7.5 min. The authors compared ESI, APCI, and APPI. The ion suppression ranged from 45 to 89 % and from 74 to 96 % on APCI and APPI, respectively. The authors... 

The possibility of ion suppression or ion enhancement effects (Schuhmacher, 2003) was assessed as well in order to characterize the presented assay. This was done by spiking blank plasma samples (n = 5) post-extraction to a concentration of 15 pg/L of each analyte. The results for these samples were compared with pure eluent samples, spiked to the same concentration. An average signal suppression of less than 1.5 % was found (1.2 % in case of flunitrazepam, 1.3% for N-desmethylflunitrazepam and 1.5% for 7-aminoflunitrazepam). 

Sample preparation 1 mL Plasma -1- 30 pL 0.5 pg/mL flunitrazepam in MeOH -1- 50 pL 1 M ammonium hydroxide, vortex, add 8 mL diethyl ether, mix 2 min, remove organic phase and dry with 0.5 g anhydrous sodium sulfate. Add a few grains of sodium chloride to the ether to prevent bumping and evaporate to dryness in a water bath at 55°. Dissolve residue in 25 pL MeOH and inject a 20 pL aliquot. 

Sample preparation 200 pL Microsomal incubation + 200 pL cold MeOH MeCN 35 21 + flunitrazepam in MeOH, centrifuge at 10000 rpm for 5 min, inject an aliquot of the supernatant. 

Figure 7-6 shows a chromatogram and the MS spectrum of flunitrazepam. This sample was prepared with a Bond-Eluat-Certify cartridge. 

Fig. 7-6. Gas chromatogram of a urine after sample preparation by solid phase extraction (SPE). MS spectrum of 7-amino-flunitrazepam AC...

Note that the top 25 detected by NFLIS are all among the most commonly abused drags in the United States. The major ones missing (but which are captured in the remaining 10% of samples analyzed by NFLIS) are baibiturates (e.g., seconal and phenobaibital, but whose rate of abuse has been declining), certain benzodiazepines (except flunitrazepam, such as alprazolam, diazepam, and chlordiazepoxide). 

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