Benzodiazepines and Barbiturates

Transcription

1 Liquid Chromatography Mass Spectrometry SSI-LCMS-004 Benzodiazepines and Barbiturates LCMS-8030 Summary A rapid, accurate, and reliable LC-MS-MS method was developed for the determination of 21 controlled substances in urine. Background Controlled substances play an important role in the practice of medicine but have the potential to be abused. Urinary testing for these drugs is an important tool in preventing diversion and abuse of controlled substances while ensuring patients with legitimate illness receive the medicines they need. Method Authentic standards for 21 benzodiazepines and barbituates were obtained from a licensed chemical supplier. Dilutions were made for optimization of mass spectrometry parameters. Positive and negative ion electrospray with polarity switching was used in Multiple Reaction Monitoring (MRM) mode for analysis. ptimized parameters are shown in Table 1. Quantifier and qualifier ions (not shown) were used for each compound. A Shimadzu Shimpack XR-DS III column (1.6 um, 2 x 50 mm) was used with a binary gradient of 25% AC and water increasing to 85% AC over 36 seconds. The column was equilibrated for 30 seconds. The flow rate was 0.6 ml/min and the column temperature was 50 o C. The injection volume was 10 ml. The standard autosampler needle rinse was used after each injection to eliminate the possibility of carryover. Calibration curves for standards in solution were prepared between 4.12 ng/ml and 1 mcg/ml. Four selected standards (alprazolam, diazepam, amobarbital, and talbutal) were prepared in a matching matrix (synthetic urine)in the concentration range of 37 ng/ml up to 2 mcg/ml. A weighting factor of 1/X was used, and all calibration points were repeated in triplicate. Low and igh concentration QC samples containing each standard at 100 ng/ml and 1 mcg/ml respectively were prepared. Four test samples were prepared containing various amounts of the selected drugs along with an unspiked fifth test sample containing only synthetic urine (see Table 2). The urine spiked samples and the matrix matched calibration curve were diluted five-fold with mobile phase prior to analysis (dilute and shoot). Each test sample and QC sample was measured five times to determine intra-day repeatability. 1

2 - + Br F Figure 1: Structures of selected drugs of abuse Table 1: MRM parameters Type Event# +/- Compound ame (m/z) Dwell (msec) Q1 Pre Bias(V) CE MRM 1 + Lorazepam 320.7> MRM 2 + itrazepam 282.0> MRM 3 + xazepam 286.7> MRM 4 + Bromazepam 315.6> MRM > MRM 6 + Temazepam 300.6> MRM 7 + Prazepam 324.6> MRM > MRM 9 + Triazolam 342.7> MRM 10 + onazepam 316.0> MRM 11 + Flunitrazepam > MRM 12 - Barbital 183.1> MRM > MRM 14 - Pentobarbital 225.1> MRM 15 - exobarbital 235.1> MRM 16 - Butabarbital 211.1> MRM 17 - Phenobarbital 23> MRM 18 - Methylphenobarbital 245.1> MRM > MRM 20 - Secobarbital 237.1> MRM 21 - Aprobarbital 209.1> Measurement Time 2

3 2,602,753 Lorazepam 663,895 itrazepam 4,577,109 xazepam 1,380,717 Bromazepam 1,200,379 8,024,220 Temazepam 8,466,527 Prazepam 497, ,738 Triazolam 126,778 onazepam 910,480 Flunitrazepam 38,350 Barbital- 279,760 Pentobarbital- 12,535 exobarbital- 86,340 Butabarbital- 191,712 Phenobarbital- 32,368 Methylphenobarbital- 19,903 Secobarbital- 32,894 Aprobarbital min Figure 2: LC-MS-MS Chromatograms of the standard mix in solution 3

4 Lorazepam r 2 = itrazepam 2.0 xazepam r 2 = Bromazepam 2 Conc. 2.5 r 2 = Temazepam 2.5 Prazepam 2 Conc. Triazolam onazepam 2.0 r 2 = Flunitrazepam r 2 = r 2 = Conc. Pentobarbital Area(x1,000) exobarbital r 2 = Butabarbital r 2 = Phenobarbital 2.0 Methylphenobarbital r 2 = Secobarbital r 2 = Aprobarbital r 2 = Figure 3: Calibration curves for standards in solution 4

5 2.1 (x1,000) 1:284.60>193.05(+) (x1,000) 1:284.60>193.05(+) (x1,000) 2:308.70>280(+) (x1,000) 2:308.70>280(+) :223.10>42.00(-) 3:223.10>42.00(-) :225.10>42.00(-) 4:225.10>42.00(-) Figure 4: Blank injection immediately following matrix-matched high standard Figure 5: Matrix Blank Spiked Measured RSD% Spiked Measured RSD% Spiked Measured RSD% Spiked Measured RSD% Lower QC Upper QC Test Sample 1 0 D 0 D Test Sample D 0 D 0 D Test Sample D 0 D Test Sample D D Test Sample 5 0 D 0 D 0 D 0 D (Matrix Blank) Table 2: Quantitative results of high and low QC, four spiked test samples, and the matrix blank. Each sample was run five times and the RSD% is shown. Results and Discussion: All 21 compounds eluted within the 1.25 minute UPLC run time with excellent peak shape and retention time stability. o carryover was detected in the blank injection immediately folowing the upper level matrix-matched calibration curve sample. Calibration curves for all compounds are shown in Figure 3. As shown in Table 2, the accuracy for all matrix-matched QC and test samples was within ±20% and the repeatability was within ±15% RSD. igher precision and accuracy could be easily achieved by using an external or internal standard as appropriate. As expected, no analytes were detected in the unspiked matrix sample. Conclusion: A rapid, accurate, and reproducible UPLC-MS-MS method for drugs of abuse in urine was developed. Dilution was the only required sample treatment prior to analysis. 5

6 LCMS-8040 LCMS-8030 LCMS-8080 LCMS-2020 LCMS-IT-TF Founded in 1875, Shimadzu Corporation, a leader in the development of advanced technologies, has a distinguished history of innovation built on the foundation of contributing to society through science and technology. Established in 1975, Shimadzu Scientific Instruments (SSI), the American subsidiary of Shimadzu Corporation, provides a comprehensive range of analytical solutions to laboratories throughout orth, Central, and parts of South America. SSI maintains a network of nine regional offices strategically located across the United States, with experienced technical specialists, service and sales engineers situated throughout the country, as well as applications laboratories on both coasts. For information about Shimadzu Scientific Instruments and to contact your local office, please visit our Web site at Shimadzu Corporation SIMADZU SCIETIFIC ISTRUMETS, IC. Applications Laboratory 7102 Riverwood Drive, Columbia, MD Phone: Fax: URL For Research Use nly. ot for use in diagnostic procedures. The content of this publication shall not be reproduced, altered or sold for any commercial purpose without the written approval of Shimadzu. The information contained herein is provided to you as is without warranty of any kind including without limitation warranties as to is accuracy or completeness. Shimadzu does not assume any responsibility or liability for any damage, whether direct or indirect, relating to the use of this publication. This publications is based upon the information available to Shimadzu on or before the date of publication, and subject to change without notice. Shimadzu Scientific Instruments, 2012 First Edition: ctober, 2012