LCMSMS Workflow

The Shimadzu triple quad is operated using a hybrid model.

1)      Mass Spec staff will set up the initial method

2)      Users will run their own samples after suitable training.

If you happen to be familiar with triple quads and Shimadzu Insight software, we are open to you developing your own methods. (Just pay for the instrument time at $50/hour)

Every method is different, but please bear in mind the following general points as you get started:

1)Initial method development requires standards. The user needs to supply these.

2)The instrument is very sensitive. For “well behaved” compounds the limit of detection can often be below 0.1ppb (0.1ng/ml) The highest concentrations that should be used are typically ~1ppm (1 ug/ml)

3)Once a method has been developed, an excellent first experiment is to run a calibration curve. That will establish a sensible working range of concentrations and allow you to become familiar with the software. The instrument is capable of monitoring many analytes in the same run. These should all be combined in each standard.  e.g., if monitoring 7 compounds, your 10ppb standard will contain 10 ppb of each compound.

4)When running samples that require some sort of purification/extraction (e.g. drugs in plasma, or environmental samples requiring pre-concentration by SPE) it is normal to use internal standards. Ideally these will be isotopically labelled (13C or 2H) internal standards. The internal standards should be added to all calibration points as well as all samples. This is a good discussion about internal standards.

5)It is an excellent idea to check your extraction efficiency! Spike a sample with a known amount of analyte and check how much goes through the extraction process. 98% is good. 15% is not!!

  Developing and validating an LC MS/MS method can become extremely complex. Our goal is always to develop a method that is fit for purpose in a reasonable length of time.