When Should You Walk on the Path to More Confident Quantitation?

Who uses a taxi anymore? Boy, was I surprised when I heard these ridesharing apps are not used by everyone these days. Recently, I successfully transitioned a good friend from a taxi service to a well-known rideshare service. Believe me, it wasn’t that easy given I had to break down the advantages and disadvantages of ridesharing companies and the types of cars (e.g. Pool, Line, etc.) each provided. Essentially, my friend had to think about which factors were important to her (comfort, cleanliness, driver likeability, space, and cost) and were not being met by her current taxi service–creating transportation bottlenecks for her.

If you are looking to identify and quantify analytes of interest in your sample, you can benefit by going through the same process that my friend did when evaluating different analytical techniques for quantitation. One of the popular techniques used for quantitation in a wide variety of samples is liquid chromatography (LC) coupled to mass spectrometry (MS). Liquid chromatography separates analytes of interest based on physiochemical properties whereas mass spectrometry does so using m/z ratios. Coupling both techniques yields quite a powerful tool to have in your analytical bag!

So, should you transition to LC-MS if you have not already? If you have already transitioned, are you using the right technology?

These are some great questions which the whitepaper “Transitioning to Confident Quantitation: A Search for a Better Tomorrow” by Dr. Debadeep Bhattacharyya addresses in great detail. You can find information on the pros and cons of adopting LC-MS as well as comparisons on triple quadrupole LC-MS versus using liquid chromatography alone, liquid chromatography coupled with single quadrupole mass spectrometry or Ligand Binding Assays (LBAs) which are summarized in Table 1 below.

Current Solution

Liquid Chromatography

Liquid Chromatography coupled with Single Quadrupole Mass Spectrometry

Ligand Binding Assays (mainly for bioanalytical assays)

Possible challenge

- Moderate resolution with separation based on retention time

- Limited specificity

- Moderate selectivity

- Inadequate sensitivity

- Insufficient selectivity

- Low specificity, especially for multiplexing. Very much depends on quality of antibodies.

How does LC-MS/MS solve for this challenge?

- Higher resolution by combining LC with Selected Reaction Monitoring (SRM)

- High specificity using retention time and mass to charge ratio (m/z)

- Superior selectivity with combining LC and m/z selectivity

- Higher selectivity with less interference from coelution or matrix

- Better sensitivity enabling lower limits of quantitation

- High specificity using retention time and mass to charge ratio (m/z)

The next time you jump in a rideshare or a taxi, give your current technique a thought to see if transitioning makes sense for you. If you do find yourself drawn to the idea of triple quadrupole LC-MS, check out this informative resource page.