Method for detecting trace calcium ions in ultra-pure ammonia water

Abstract

The invention relates to a method for detecting trace calcium ions in ultra-pure ammonia water. The method comprises the following steps: diluting a sample; directly detecting the concentration value of the trace calcium ions in an ultrapure water and hyperpure ammonia water diluent by utilizing a standard solution signal comparison test method, and carrying out accurate calculation to obtain the content of the trace calcium ions in a product. The method in the invention can be used for eliminating the error of the system, and the accuracy of the method is improved; the method in the invention has the characteristics of simple and rapid analysis process, reliable data and low cost, and is applicable to the rapid detection in industrial production.

Description

technical field [0001] The invention relates to the technical field of detection methods, in particular to a detection method for trace calcium ions in ultra-high-purity ammonia water. Background technique [0002] With the rapid development of the information industry, higher requirements are put forward for the purity of some major supporting materials. For example, ammonia water used in the manufacture of semiconductor VLSI, its application technology requirements range from the earliest ppm single metal ion to ppb single technical ion Up to the present ppt single metal ion. [0003] With the rapid development of the semiconductor industry, high-purity ammonia water is widely used in the semiconductor chip manufacturing process, so higher requirements are put forward for the testing of high-purity chemicals. Generally, the content of impurities is required to be controlled at 20-50ppt, and the analytical The limit requirement is 5-10ppt. [0004] At present, the existin...

AI Technical Summary

Problems solved by technology

Using the standard solution signal comparison method to dilute the sample seriously ignores the system differences between the standard solution and the ammonia solution, that is, their responsivity on the ICP-MS instrument is completely different, and the corresponding standard curves will also be very different. The deviation will not be eliminated. Using the standard liquid signal comparison method to distill the sample to determine the calcium ion in the ultra-pure ammonia water will also lead to different degrees of interference during the sample processing process, such as the solubility of the container, dust in the air, and the product, etc. , and the time-consuming will be greatly increased

[0005] Using the existing industrialized test method, due to the outdated test method and the easy interference in the operation process, the error of the data has reached more than 20%, and the absolute error is greater than 25ppt. It has the disadvantages of unstable test results, low accuracy, cumbersome operation, and large errors.