An alternative solution to overcome carryover issues in bioanalysis.

LC MS/MS instruments are considered as the analytical technique of choice for bioanalytical assays. The LC MS/MS technique acquired this status due to its robustness, specificity, sensitivity and good precision and accuracy. Nonetheless, with the use of these instruments, users also have to deal with some complex analytical problems such as carryover. Even if carryover is well known and widely discussed, it still remains a common issue in bioanalytical work. Although new autosampler instruments manufactured are specifically designed to fix the problem, the issue is still present because methods developed by the industry also change and evolve with the instrument. Requests for wider dynamic ranges and the use of a very sensitive detector that can reach very low LOQ are among the reasons. This article reviews the causes of carryover and proposes an autosampler needle seat backflush as a novel solution to address the issue.