Method using static adsorption ion exchange technology to separate and measure copper ions in salt

Abstract

The invention discloses a method using a static adsorption ion exchange technology to separate and measure copper ions in salt. According to the method, an iminodiacetic acid type chelate resin is used to adsorb copper ions in a sodium chloride water solution through static adsorption; then a diluted nitric acid solution is used to wash copper ions from the resin; and after copper ions and the high salinity matrix are separated, the copper ions can be detected by atomic absorption spectrum. The static adsorption is realized through a cage shaped adsorption device; the artificial filtering is not needed, the separation is simplified, a large amount of spectrum interference caused by sodium chloride is eliminated, the subsequent detection is very simple, the results are accurate and reliable, the sensitivity is high, the selectivity is good, and the recovery rate and precision are both good.

Description

technical field [0001] The invention relates to a method for measuring the content of copper ions in table salt, in particular to a method for separating and enriching copper ions from table salt and then using atomic absorption spectroscopy for detection. Background technique [0002] There is a large amount of sodium chloride in high-salt samples such as pickled food, soy sauce, table salt, and brine. In the presence of a large amount of sodium salt, the determination of trace heavy metals is a recognized problem in analytical chemistry. For example, when using AAS to detect trace heavy metal elements At the same time, sodium chloride will affect the arc temperature and produce a large background interference, resulting in the inaccurate determination of some trace heavy metal elements. When ICP or ICP-MS is used for detection, a large amount of sodium chloride will also block the nebulizer or deposit on the torch and sampling cone, thereby affecting the normal use of the ...

AI Technical Summary

Problems solved by technology

[0002] There is a large amount of sodium chloride in high-salt samples such as pickled food, soy sauce, table salt, and brine. In the presence of a large amount of sodium salt, the determination of trace heavy metals is a recognized problem in analytical chemistry. For example, when using AAS to detect trace heavy metal elements At the same time, sodium chloride will affect the arc temperature and produce a large background interference, resulting in the inaccurate determination of some trace heavy metal elements

When ICP or ICP-MS is used for detection, a large amount of sodium chloride will also block the nebulizer or deposit on the torch and sampling cone, thus affecting the normal use of the instrument

[0003] At present, the methods for detecting heavy metal pollution residues in high-salt samples at home and abroad either use organic solvents, or require self-made complexing agents, or use special equipment, which are not easy to promote in ordinary laboratories. The complexing agent has a short lifespan and cannot be reused for a long time

The matrix improver method is often used, such as: ammonium dihydrogen phosphate, magnesium nitrate, palladium nitrate, etc., but experiments have proved that the improvement ability of the matrix improver is very limited, and the sodium chloride content of the system is best controlled at 1 / 1000 Within five, when encountering samples with high salt content (such as saturated saline), the background interference cannot be overcome at all. At the same time, there are trace amounts of heavy metals in food, it is not advisable to use dilution methods to reduce the content of sodium chloride, so the current The method of adding matrix improver is only a palliative solution that cannot fundamentally solve the problem

The matrix matching method actually still depends on the matrix modifier. The limitation of using the matrix modifier to eliminate the interference of sodium chloride still exists, and it is still unable to accurately detect high-salt samples.

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