Before we get into our extractions, we need to set up our LC/MS to detect our analytes of interest. The LC will provide the chromatography - or separation of our analytes - and the MS will support detection. So which one do we evaluate first? Well, if you can’t “see” the analytes, what good is perfecting their chromatography? So, first, let’s get the MS focused, or tuned, for optimum analyte detection.
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?
Synthetic cannabinoids are some of the most widely abused drugs in the world. They are structurally similar and have similar effects to marijuana but are frequently referred to as “legal highs”. Chemists are constantly changing the structures of these compounds to keep them in a legal state and governments can’t keep up with adding them to scheduled lists. So, how do we analyze for these compounds? How can they be easily extracted from whole blood?
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.
Often the question arises asking how can I extract both acids and bases with the same Supported Liquid Extraction (SLE) procedure. Is this possible? And how?
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?