Updated: Nov 21, 2019
The CAMAG laboratory have produced a fully validated, automated method using the CAMAG DBS-MS 500 system for the online extraction of Phosphatidylethanol (PEth) from Dried Blood Spot (DBS) samples with immediate analysis by LC-MS. Phosphatidylethanol (PEth) is a direct biomarker for alcohol that is accumulates in the blood after alcohol consumption and has been shown to be retained in the body for up to 12 days. PEth is formed when the consumed ethanol binds to the membrane of the red blood cell, meaning that PEth remains long after ethanol has been eliminated. Due to the long retention time of PEth in the blood a comprehensive profile of drinking habits and periods of abstinence from alcohol can be determined from blood samples. This makes PEth the ideal biomarker for monitoring chronic alcohol abuse, workplace alcohol testing, custody cases and driving aptitude tests.
The analysis of PEth as a marker for alcohol is not a new concept, but the main drawback for PEth analysis is that it is unstable in liquid blood after it is removed from the body unless the sample is frozen immediately, this poses difficulties for sampling, transportation and overall reliability of the sample. This is where Dried Blood Spot (DBS) sampling presents as the perfect solution to overcome these challenges. DBS sampling involves blood drops from a finger prick being transferred to a filter paper and then air drying the paper. The sampling process is minimally invasive and does not need to be performed by a medical professional. The drying process also stops the enzyme activity in the blood which means that the DBS sample is stable at ambient temperature and does not require any special transportation.
Once received by the lab, DBS cards can be put directly into the CAMAG DBS-MS 500 with no further preparation. The CAMAG DBS-MS 500 offers high sample throughput, with the ability to hold a maximum of 500 DBS cards with each sample taking only 6 minutes to run; from initial scanning and cataloguing of the card to receiving the final PEth concentration result. The DBS-MS 500 can be interfaced with any LC-MS system to work in harmony with your existing analytical instrumentation. The validated and novel online-SPE-LC-MS method with automated sample preparation using a CAMAG DBS-MS 500 system reduces manual sample preparation to an absolute minimum proving the automated analysis of PEth in Dried Blood Spot can provide a fast and accurate solution for abstinence monitoring.