Here is a explanation without any symbols or logos:
Types of Detectors Used in HPLC
1. UV-Visible (UV-Vis) Detector
- The most common type of detector.
- It measures how much ultraviolet or visible light a compound absorbs.
- Useful for compounds that absorb UV light, such as many organic molecules and drugs.
2. Photodiode Array (PDA) Detector
- A special type of UV detector that measures light at many wavelengths at the same time.
- Helps to identify compounds by their full absorption spectrum.
- Good for analyzing mixtures with several different compounds.
3. Refractive Index (RI) Detector
- Measures changes in how light bends when different compounds pass through.
- Works for compounds that do not absorb UV light.
- Commonly used for sugars, alcohols, and polymers.
4. Fluorescence Detector
- Detects compounds that give off light (fluoresce) when they are excited by a specific wavelength.
- Very sensitive and selective.
- Used for compounds such as vitamins, proteins, and certain drugs.
5. Conductivity Detector
- Measures the electrical conductivity of the mobile phase as compounds come out of the column.
- Mostly used in ion chromatography to detect ionic substances like salts or acids.
6. Electrochemical Detector
- Detects compounds that can be oxidized or reduced by measuring electrical current changes.
- Highly sensitive.
- Commonly used for biological molecules and pharmaceuticals.
7. Mass Spectrometric (MS) Detector
- Measures the mass-to-charge ratio of ions.
- Gives both identification and quantity of compounds.
- Used in LC-MS systems for drug, food, and environmental analysis.
In short:
- UV-Vis and PDA detect light absorption.
- RI detects refractive index changes.
- Fluorescence detects emitted light.
- Conductivity and electrochemical detectors sense electrical changes.
- MS detects the mass of molecules.