This is a question that I am often asked by very smart people that just haven’t had time to learn the process. An optimized sample preparation method is critical for an accurate, specific, robust clinical LC-MS/MS assay. A good sample prep method can improve accuracy and precision, provide longer LC column lifetime, and keep your LC-MS/MS system clean.
We’ve all been there. We prepare a batch of samples to analyze, prime our systems, warm up the detector, and within 2-3 injections we receive an error message stating that an integral component has failed for one reason or another. This can be a dreadful experience, especially for a routine production laboratory.
When trying to develop a new method for the detection of a drug panel, you need to refer to reliable sources to learn all you need to know regarding your analytes. For this post, we’ll go in detail through the search process with analytes like naloxone, buprenorphine, norfentanyl and methadone using urine as our matrix of focus.
The sole purpose for method development is to construct a robust and analytically sound method that will not just pass the barriers of validation, but provide physicians and patients with sound and reliable results. But where to start?
Let's face it, the whole solid phase extraction method development process can be time consuming and expensive. So Dilute-and-Shoot methods end up being the choice in some laboratories. The problem is that these methods are dirty and lead to a lot of other issues. In this blog post, I'll be discussing filtration methods and how those are a superior option to Dilute-and-Shoot.
Most clinical and forensic labs have a used a traditional approach for drug testing called screen with reflex to confirmation. This involves analyzing samples using an immunoassay technique that identifies a drug class. Positive immunoassay results are then analyzed by a second more specific method, like GC-MS or LC-MS/MS, to identify and quantitate specific drug analytes.
Have you ever encountered problems loading your samples onto an SPE or SLE plate? Aside from sample viscosity or cartridge blockages, a good troubleshooting step to start with is ensuring that you are achieving complete frit coverage on the load.
It happens to all of us. We're getting a new method developed and validated and then it comes time to run our negative urines. And everything comes up as positive! There are peaks for our analytes of interest in every urine that we run! How is that possible?