Liquid chromatography are widely used in modern life. As modern analytical instruments, they possess sophisticated internal structures and professional operating systems, playing a vital role in fields such as biomedicine, environmental chemistry, and petrochemicals. They provide strong technical support for biological research and various analytical tasks, making our work and life more efficient and convenient. The basic principle of a liquid chromatography is to separate and identify analytes based on differences in partition ratios between a liquid‑solid system or two immiscible liquids.
So, how should we properly maintain a liquid chromatography in a humid environment? Let’s find out.
Operators usually focus on the accuracy of analytical results, and the detector is the “eye” of HPLC. Humid weather can easily cause the precision optical components inside the detector to become damp, leading to decreased sensitivity, wavelength calibration failure, and in severe cases, simultaneous damage to the lamp circuit board, preamplifier board, and CPU board due to short circuits. In contrast, such problems are less common in dry climates like those in northern regions. It is clear that the influence of a humid environment on the instrument cannot be ignored.
Before the rainy season arrives, it is recommended that users place the instrument in a well‑ventilated laboratory with ambient humidity below 70%. At the same time, the laboratory should be equipped with a dehumidifier, air conditioner, or ventilation system. On the surface, these devices add some cost, but in the long run, their contribution to preserving instrument life and maintaining data accuracy will far exceed the initial investment.
Key precautions for using a liquid chromatography:
Mobile phase purity: All mobile phases must be of HPLC grade. For the aqueous phase, it is recommended to use ultrapure water of 20 MΩ. After degassing, the mobile phase should not be shaken vigorously to avoid bubble formation.
Column protection: The column is very fragile. When developing an analytical method, it is advisable to avoid passing liquid through the column prematurely.
Strict filtration: All liquids that will pass through the column must be strictly filtered.
Pressure control: The system pressure should not be too high; it is recommended not to exceed 15 MPa.
Thorough cleaning: Because buffer salts can crystallise upon contact with organic solvents, damaging the column, the system must be thoroughly cleaned with distilled water each time the mobile phase is changed.
Frequently Asked Questions about special maintenance in humid environments:
Q: Why should a liquid chromatography not be switched on and off frequently in humid weather?
A: Keeping the instrument continuously powered on uses the slight heat generated by its internal components to effectively drive away moisture, preventing precision circuits and optical components from being damaged by condensation.
Q: How should condensation be handled when turning on a liquid chromatograph in humid weather?
A: Turn on the air conditioner’s dehumidification mode and power on the instrument 2‑4 hours in advance to preheat it, allowing the instrument to warm up slowly so that moisture evaporates naturally.
Q: How should spare columns be stored correctly during the rainy season?
A: Spare columns must be tightly capped at both ends and placed in a sealed bag containing desiccant to prevent the stationary phase and packing from absorbing moisture and deteriorating.
Q: What special effects does a humid environment have on mobile phase preparation?
A: High humidity accelerates the absorption of moisture by volatile buffer salts in the mobile phase, changing their concentration and pH. Therefore, such mobile phases should be prepared fresh just before use and stored in sealed containers.
