Brief description of basic knowledge of trace element analyzer

It is believed that many people still lack or have little knowledge of the expertise of trace element analyzers. In this instrument world network for everyone to point out the basic common sense of trace element analyzer. As long as you master a few points, you can easily deal with it.

The first is the repetitive stability, which is the basic requirement of the instrument and the basis of analysis and testing. This indicator is not good, and the others will not be able to talk about it. It is purely flickering. If the same sample, the results obtained by the test are fluctuating, showing a large difference, which indicates that the instrument has a problem. If you look at the actual measurement of the instrument, some manufacturers do not allow the operator to conveniently superpose the curve and do not set the procedure for obtaining the coefficient of variation in order to avoid the observation of repeatability. This is because the performance of the instrument is not good enough to be seen by others. The problem is that producers are evading this issue.

Actually, the variation coefficient of some manufacturers' instruments is between 10% and 20%. The error greatly exceeds the relevant regulations. The reliability of the results thus obtained is low. The coefficient of variation of the products of our company is controlled below 5%, and the test can be performed by the instrument. At a glance. Electrochemical polarographic analysis uses very small electrodes (drops of mercury), and the sensitivity is related to the specific surface area of ​​the electrodes. The area has a large signal-to-noise ratio (referring to the ratio of signal to noise), high sensitivity, and strong anti-interference ability. Since the area of ​​the drop electrode depends on the volume, if it is large, it must be controlled without falling. Therefore, the surface area of ​​the electrode is severely constrained. This determines the noise and repetitiveness of the instrument made by the conventional electrode, which is currently used by all. Electrode-like apparatus is a common problem. Only my company's products solve this problem through the use of a series of technologies such as the use of a static mercury electrode. In this area of ​​technology is better than any of the same instruments, which can be confirmed by on-site comparisons.

Another type of electrochemical instrument evades this type of problem. Solid electrodes are used to measure all elements, and mercury electrodes are used to attack instruments that use polarographic methods from an environmental perspective. In fact, in the test, mercury works in a closed environment and does not come in contact with the atmosphere. Just like the sphygmomanometer, the current standard of measurement is mercury sphygmomanometer, which is still widely used. The use of polarographic analysis methods for mercury drop electrodes is a national standard method and industry standard in many fields. For example, zinc determination in serum is a method prescribed by the Ministry of Health's inspection protocol, and there are more polar analysis standards in foods. While the use of solid electrodes (such as glassy carbon electrodes) to measure certain specific elements such as lead is good, it is impossible to use all of them to solve the detection of all elements, both theoretically and practically. All lack evidence. Those who spend a lot of money to purchase such instruments either have insufficient knowledge or have other reasons.

The trace element analysis is low in content, has a small useful signal, and has high technical requirements. Good reproducibility, high sensitivity, stable instrument performance, poor performance, poor repeatability, poor overall instrument infrastructure, and the need to use various means to cope with users and conceal the truth, and users know little about this. The simplest way of judging is to see if the instrument is set up so that it is convenient to perform multiple comparisons of curves and to directly observe the repeatability function, and whether the coefficient of variation can be easily found. After further measurement of zinc in the blood, repeated tests have been performed to see if the repeatability is good or bad. Because the zinc content is low, the performance of the instrument can be evaluated. Before testing, blanks need to be checked to prevent false impressions caused by high reagent blanks. It is possible to examine other performance indicators on the basis of good repeatability. Objectively speaking, as long as the repeatability is good, other performance indicators should be less problematic. But the kind of instrument that uses one kind of electrode to make all elements, make the difference between blank standard solution and measured sample. That is to say, if you only do a simple standard solution without doing a sample, it may be very good, but when you add a sample, the sample brings a variety of disturbances to make a very large change in repeatability, linearity, and sensitivity.

At present, the use of solid glassy carbon electrode for measuring blood lead is more mature. Others should look at the national and industry standards for this area, whether there is any literature in this area, and whether there is an actual sample for the sample. If not, some companies have used this electrode in a very short period of time to come up with a set of analysis methods. Whether it is a superpower or another reason requires interested parties to think for themselves.