LC-MS/MS analysis

What is LC-MS/MS analysis used for?

The excellent detection capabilities of LC-MS/MS give it applications in multiple fields. Measurlabs offers a range of analysis services with the technique, including the following:

• Detection and measurement of per- and polyfluoroalkyl substances (PFAS) in food, water, consumer goods, and environmental samples. Testing can be based on EPA Method 1633, which is emerging as the go-to methodology for PFAS screening in the US.

• Food contaminant screening, including for plant alkaloids, acrylamide, and pesticides.

• Analysis of active ingredients and impurities (such as nitrosamines) in pharmaceuticals.

• Testing nutritional supplements for the presence of unauthorized substances.

These are just some examples of popular LC-MS/MS applications. Do not hesitate to contact our chemical analysis experts to discuss the method's suitability for your samples.

How does LC-MS/MS work?

A typical triple quadrupole (QqQ) LC-MS/MS setup initially uses liquid chromatography to separate a sample into its components. The separated components are then ionized and introduced into the first mass spectrometer, which selects ions based on their mass-to-charge ratio. The selected ions are fragmented in a collision cell, and the resulting fragments are passed through a second mass spectrometer before being detected.

Sample requirements and preparation

Before injection into the LC-MS/MS system, samples must be in a diluted liquid or solution form. This often involves dilution with standard solvents like water or acetonitrile. Sample preparation may also include steps to extract, purify, and concentrate analytes and remove interferences. Depending on the target analytes, one option is to use the QuEChERS method, which is used especially for pesticide residue and mycotoxin analysis.

Advantages and limitations of LC-MS/MS analysis

LC-MS/MS offers greater separation of complex samples than conventional LC-MS, allowing the detection of target analytes with a higher degree of specificity. Furthermore, the fragmentation provided by the tandem mass spectrometry allows for the characterization of complex organic molecules and distinguishing them from other molecules with similar mass spectra.

The main drawback of LC-MS/MS is its relatively low throughput. Data analysis and characterization, particularly in the case of very complex mixtures, can also be time-consuming.