Deuterated Compounds and Their Role in Mass Spectrometry

What is a deuterated compound?

A deuterated compound is a molecule in which one or more hydrogen atoms have been replaced by deuterium, a stable, heavier isotope of hydrogen. The name usually shows how many positions are labelled, for example -d3, -d4 or -d5. Chemically the labelled molecule behaves almost identically to the unlabelled one, but it has a slightly higher mass.

Why mass spectrometry uses them

In LC-MS and GC-MS, a deuterated version of the analyte is often added to every sample as an internal standard. Because it travels through extraction and chromatography in nearly the same way as the target compound, it compensates for losses and for changes in instrument response. The mass spectrometer can still tell the two apart because of the mass difference.

This approach is widely used in bioanalysis, metabolism studies, environmental testing and pharmaceutical method development, wherever accurate quantification at low levels is required.

Choosing a labelled standard

When selecting a deuterated standard, laboratories consider the number of labelled positions, the location of the labels and whether they could exchange during sample preparation. These details should be checked against the analytical method before purchase.

The Deuterated Compounds category at Cadulac Chemicals Ltd lists labelled versions of many active substances and metabolites. Search by name or CAS number and send an enquiry with your required quantity; isotopic details and documentation are confirmed upon enquiry.