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Analysis of Benzodiazepines in 5 Different Biological Matrices Using dSPE WAX Tips

Analysis of Benzodiazepines in 5 Different Biological Matrices Using dSPE WAX Tips

Clean-up Method for Rapid Analysis in Biological Samples

Benzodiazepines and sedatives are some of the most commonly abused drugs in the nation and are often found in cases involving driving under the influence of drugs, sexual assaults and overdoses.

Unfortunately, most existing methods used to identify benzodiazepines and sedatives across matrices are labor intensive and time-consuming. A simple cleanup method that can be applied across multiple biological matrices would be an ideal solution to increase the throughput capabilities of forensic laboratories. 

Unlike traditional methods for SPE, dispersive pipette extraction technology for clean-up focuses on removing matrix interferences, while keeping the benzodiazepines in the sample solution. dSPE tips containing loose weak anion exchange (WAX) sorbent remove phospholipids and small non-amphoteric acids that can cause ion suppression. By simply aspirating and dispensing the sample solution with WAX dSPE tips, matrix interferences are removed with minimal loss of the drug. This reduces the time required for extraction by minimizing several conditioning and washing steps, reducing the volume of solvent required for elution and eliminating analyst error from multiple transfer steps. The initial addition of acetonitrile to the sample solutions keeps the benzodiazepines and sedative hypnotics from binding to the sorbent. (1)

We reported an LC-MS/MS analysis of benzodiazepines using dispersive pipette extraction technology for clean-up.  dSPE tips with WAX sorbent can provide sample preparation across five matrices for a simple and fast INTip solution.


PlatformDPX Pneumatic Extractor
Pretreatment • 250 μL sample of the following matrices: urine, blood, liver tissue, brain tissue and stomach content 
• 50 μL internal standards 
• 750 μL acetonitrile
• Centrifuge
Dispersive Pipette Extraction Technology5 mL Universal dSPE Tips with 60 mg WAX
SampleAspirate and dispense supernatant solution 3 times – 60 seconds
Prep for injectionTransfer 50 μL and add 80 μL of the LC mobile phase for injection

Download the Application Note for this Method

Learn more about this method that has been validated at Orange Country Crime Lab in the Journal of Analytical Toxicology Article –

  1. Mata, Dani C. (2015) Ultra Performance Liquid Chromatography with Tandem Mass Spectrometry for the Quantitation of Seventeen Sedative Hypnotics in Six Common Toxicological Matrices. Journal of Analytical Toxicology, 40, 58-63

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