Detectors in Chromatography: Function and Types

What are the different types of detectors used in chromatography?

Classify the detectors according to whether they are used for gas chromatography, liquid chromatography, or both types of separations.

Types of Detectors in Chromatography

Detectors in chromatography are devices used to detect and measure the analytes present in chromatographic separation.

- Flame ionization detector (FID)

- Thermal conductivity detector (TCD)

- Electron capture detector (ECD)

- Flame photometric detector (FPD)

- Mass spectrometry (MS)

- Refractive index detector (RID)

- UV-Visible detector

- Diode array detector (DAD)

- Fluorescence detector

- Electrochemical detector

- Evaporative light scattering detector (ELSD)

Understanding Detectors in Chromatography

Detectors in chromatography play a crucial role in the analysis of separated compounds. They provide valuable information about the presence and quantity of analytes in a chromatographic system.

Gas chromatography detectors such as Flame ionization detector (FID), Thermal conductivity detector (TCD), Electron capture detector (ECD), Flame photometric detector (FPD), and Mass spectrometry (MS) are commonly used in gas chromatography. FID is specific for organic compounds and offers excellent sensitivity, while TCD is non-specific and can detect a wide range of compounds. ECD is selective for compounds with electronegative groups, FPD is used for sulfur and phosphorus compounds, and MS provides accurate mass measurements.

Detectors like Refractive index detector (RID), UV-Visible detector, and Diode array detector (DAD) can be used in both gas and liquid chromatography separations. RID measures refractive index changes, UV-Visible detectors detect compounds based on light absorption, and DAD allows spectral analysis.

Fluorescence detectors, Electrochemical detectors, and Evaporative light scattering detectors (ELSD) are commonly used in liquid chromatography. Fluorescence detectors are sensitive, Electrochemical detectors measure electroactive compounds, and ELSD is universal for non-UV-absorbing compounds.

The choice of detector depends on the application, sensitivity, and selectivity required for the analysis. By understanding the functions and types of detectors in chromatography, scientists can optimize their analytical methods for various compounds and samples.