Urine samples are composed of many interferents which can cause ion-suppression or ion-enhancement when analyzing by mass spec. Build up of these matrix components over multiple sample injections can lead to loss of signal in the mass spec and even unexpected changes in your chromatographic separation. We are going to discuss why not performing adequate sample prep can be detrimental for your analyses.

Most clinical chemists have developed a blood, serum or plasma assay using a protein crash because it is inexpensive and generally removes proteins that interfere with detection or the analysis in some way. But is this always true?

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.  

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?

If you are frustrated with low recoveries caused by protein binding during Supported Liquid Extraction (SLE) and Solid Phase Extraction (SPE), this blog post will give you a few tips. Proper sample pre-treatment is the key to solving this issue.

In this blog post, we will discuss how to determine the optimal sample volume for a sorbent bed mass.  We have developed an adequate solid phase extraction method for our laboratory. However, we're starting to notice some oddities when we extract and analyze our samples. Could we be losing compounds from our sample?