Gerstel: Intelligent Automation for GC/MS and LC.MS

A Hands-Off Approach to Dried Blood Analysis

DBS_SPExos_2.jpg

Dried blood spot samples have many advantages for researchers and analysts. The use of dried blood spot cards makes it much easier to collect, store and ship samples compared to that of whole (liquid) blood. And because test volumes are much lower, fewer animals are needed for preclinical work. In addition, you’ll get higher quality data because you can perform serial sampling from just one animal.

However, working with dried blood samples has traditionally involved several manual steps. These include physically punching a small disc out of the spot’s center, as well as solvent-based extraction and cleanup steps used to improve detection limits.

The newly created GERSTEL DBSA (dried blood spot analysis) system can completely automate each step of the analysis of dried blood spots, reducing solvent use, increasing sample throughput, and ensuring high-data quality. To test this new system, GERSTEL researchers used dried bovine and rat blood spot samples spiked with ketamine and amitriptyline solutions, drugs normally found and researched in animals.

The researchers used solutions spiked with the anesthetic ketamine, tricyclic antidepressant amitriptyline, and non-steroidal–anti-inflammatory ketoprofen, and deuterated analogues d4-ketamine and d3-amitriptyline. The GERSTEL MultiPurpose Sampler (MPS) DBSA system (made up of MPS, GERSTEL DBS and SPExos Options) performed automated sample prep sequences. Following automated desorption, the samples could be directly injected after extraction by using the GERSTEL SPExos Option. Chromatographic separation and analysis was then performed using an LC/MS/MS system. 

The team found that accuracy data from rat blood spot samples averaged 86.8 percent for ketamine, 87.2 percent for amitriptyline, and 104 percent for ketoprofen. Precision data averaged 6.19 percent for ketamine, 4.62 percent for amitriptyline and 6.24 percent for ketoprofen. For bovine blood spots, accuracy averaged 112 percent for ketamine, 109 percent for amitriptyline, and 102 percent for ketoprofen. Precision data averaged 4.45 percent for ketamine, 6.16 percent for amitriptyline, and 5.74 percent for ketoprofen. Thus, these data indicated that the DBS-SPExos-LC/MS/MS method was very accurate and precise.

The new automated dried spot extraction method was very efficient, and easily controlled by GERSTEL's MAESTRO software. Linear calibration curves for both dried rat and bovine blood showed R2 values of 0.99 or greater, indicating a powerful, accurate and easy method to make working with dried blood samples even more convenient. 

You can read more about the GERSTEL research team’s work on automated dried blood spot analysis, including optimized preparation and cleanup steps, in the application note, “Automated Desorption, SPE Extraction, and LC/MS/MS Analysis of Dried Blood Spots.” After reading the application note, we are happy to discuss how automated dried blood spot analysis can be an integral, efficient part of your analytical work. Just reach out.