Causes and Solutions of Poor Sample Reproducibility of Secondary Thermal Analyzer

    secondary thermal analyzerIt can be easily used for various sampling methods, such as sampling the external environment with a dry cell air sampler and then analyzing in the laboratory, or using a mobile thermal analyzer/gas chromatograph platform for on-site sampling analysis. The secondary thermal analyzer can also be installed directly at the inlet of the chromatograph, which can be a special case of the cracking sampler.

Nowadays, thermal analysis sampling technology has been widely used in life science, industry, agriculture, environmental protection, pharmaceutical, tobacco, education, petrochemical, food, electronics and many other fields. So, the secondary thermal analysis instrument is now the sample reproducibility difference is what? Below, Xiaobian will explain in detail!

1. Metering pumps are not allowed.

Determine the accuracy of metering pump suction. Put enough pure water into the sample bottle, wipe the outside water clean, weigh with an analytical balance, record the reading W1, put it into the sample inlet plate, set the sample inlet procedure, import 100 μL of the sample for ten consecutive times, then dry the water on the surface of the sample bottle with filter paper, weigh with a balance, and read W2, the W1-W2 value should be the mass of 1ml pure water at the corresponding temperature. If the difference is not large, the measuring pump will not be blocked. If there is a problem with the metering pump, there may be problems with the plunger rod or sealing ring of the metering pump.

2. The six position valve is worn.

Remove the six-position valve according to the instructions of the thermal analysis sampler and observe the three openings for wear. If the wear is serious, replace the new six-position valve, assemble and debug according to the operation in the book, with good reproducibility.

In daily use, the maintenance and troubleshooting of the secondary thermal analyzer is the accumulation of experience again and again. Each component of the liquid chromatography is reciprocal. If one component has a problem or is contaminated and clogged, it may affect subsequent components. At the same time, check whether there is a problem with the front.

For example, if the baseline is unstable, check whether the detector is contaminated, check whether there is a problem in the flow phase, whether the sample is dirty, whether the column is contaminated, whether the column is stable, whether the ambient temperature is stable, etc. Therefore, sometimes checking problems is more difficult than machine maintenance, which requires us to accumulate more experience, observe more, and use more brains in order to better use the thermal analyzer.