What are hyphenated techniques? Chromatography today


Over the years, countless analytical techniques have been developed with specific goals or objectives. Nowadays, scientists have a panoply of analytical tools at their disposal. What if these methods were combined? This is where hyphen techniques come into play…

Hyphen Techniques: The Basics

The term “hyphenation” was coined by Thomas Hirschfield in 1980. Hyphenation techniques couple two (or more) methods to solve more complex analytical problems. More specifically, it is the combination of a separation technique with spectroscopic detection technology.

Separation techniques include gas chromatography (GC), liquid chromatography (LC), high performance liquid chromatography (HPLC), and capillary electrophoresis (CE). These methods are used to separate the components of a sample substance in order to identify each specific component.

On the other hand, spectroscopic detection technology is used to analyze the molecular structure. This allows researchers to calculate the molecular weight of various components. In turn, this allows them to quantify each component of a sample to get a better idea of ​​its composition.

Different Types of Hyphen Techniques

As mentioned above, there are a number of separation methods that can be used as a starting point for hyphenated techniques. This is combined with a choice of spectroscopic detection methods, such as mass spectrometry (MS), nuclear magnetic resonance (NMR) spectroscopy, Fourier transform infrared (FTIR or simply IR), photodiode array (PDA) and fluorescence emission.

The result is a range of commonly used hyphenated techniques, including:

  • GC-MS
  • LC-MS
  • LC-IR
  • GC-IR
  • LC-NMR
  • CE-MS

It should be noted that the combination of separation and detection is not limited to two techniques, with LC-MS-MS and LC-NMR-MS using multiple detection methods, while the likes of LVI-GC-MS and SPE -LC-MS add sample preparation and purification to chromatographic analyses.

What are the advantages of hyphenated techniques?

Hyphenated techniques combine the power of separation and quantification for deeper analysis, in turn solving more complex problems. Their benefits include improved sample throughput, reproducibility and faster analysis with a higher degree of automation, as well as simultaneous separation and quantification. The closed system also means there is a reduced risk of contamination.

An example of these benefits in practice is discussed in the article “Accelerating ADC Development with Mass Spectrometry”. It explores how LC-MS and other MS-based methods are used to accelerate the development of antibody-drug conjugates for targeted therapy.

A more complex example comes from the analysis of cannabidiol (CBD) using SFC-CD-MS, which combines supercritical phase chromatography with circular dichroism and mass spectrometry detectors. This allows universal detection of cannabinoids as well as specific detection of stereoisomers, as discussed in the article “Analysis of cannabidiol in CBD products by SFC-CD-MS”.


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