Method for Determination of Selenium Content in Vegetables by Inductively Coupled Plasma Mass Spectrometry

Abstract

The invention relates to a method for measuring selenium content in vegetables by collision cell-inductively coupled plasma mass spectrometry. Microwave digestion is used for pretreatment, oxidizing nitric acid and hydrogen peroxide are added, and digestion is carried out in a microwave digestion instrument to remove the dissolved selenium. The solution was measured by an inductively coupled plasma mass spectrometer. The present invention adopts the mass number 80 with higher abundance to measure selenium. The instrument adopts the collision cell mode, and the measurement conditions are improved by adjusting the collision cell voltage and the helium gas flow rate, reducing the interference of argon gas, and significantly improving the precision of the measurement results. accuracy and sensitivity. Microwave digestion is used to pre-treat the sample. The microwave can penetrate the polytetrafluoroethylene digestion tank to heat the sample. In the closed digestion tank, the pressure is high, the digestion speed is fast, and the digestion effect is good; the method is simple, sensitive, accurate and Fast, but also suitable for the determination of selenium in fruits, eggs and other foods.

Description

technical field [0001] The invention belongs to the technical field of food analysis, and relates to a method for measuring selenium content in vegetables by a collision reaction cell-inductively coupled plasma mass spectrometer. Background technique [0002] Selenium is an essential nutrient element for the human body. It has anti-cancer, anti-oxidation, anti-aging and other effects. At present, there are various selenium-enriched foods in the domestic market, but the specific content of selenium needs to be determined further. Therefore, the determination of selenium It is of great significance. At present, the detection of selenium mainly includes hydride atomic absorption spectrometry, hydride atomic fluorescence method and inductively coupled plasma mass spectrometry. The detection method of selenium is mainly based on hydride atomic fluorescence method, but this method has In the process, it is necessary to consider the different response values ​​of different valence ...

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Problems solved by technology

Theoretically, the mass number 80 with the highest abundance should be selected for the determination of selenium, but due to the interference of the mass number 80 when the inductively coupled plasma mass spectrometer is used for the measurement, the carrier gas used is Ar gas, and the mass of Ar When the number is 40, it has a strong (Ar 40 +Ar 40 ) 80 Interference, at the same time, if there is a high content of calcium in the food, it also exists (Ar 40 +Ca 40 ) 80 Therefore, in the existing ICP-MS method for the determination of selenium, when the mass number of 80 is used, there are interferences that are difficult to eliminate in the detection process, so previous studies can only use other low-abundance selenium for technical reasons. Mass numbers such as 78, 82 and other mass numbers, such as Yin Zhong’s research on the determination of selenium in grain by microwave digestion-collision reaction cell technology inductively coupled plasma mass The method of selenium content in agricultural products" and other articles all adopt the mass number of 78 of selenium to measure, and the result that causes like this is exactly that sensitivity is lower

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