Extraction method and detection method for iodine in milk powder

Abstract

The invention relates to an extraction method and a detection method for iodine in milk powder. The extraction method for iodine in the milk powder of the invention comprises the following steps: (1)weighing a milk powder sample and dissolving the sample; (2) adding a potassium ferrocyanide solution and a zinc acetate solution to the milk powder treated in the step (1), shaking and centrifuging to obtain an upper liquid A and a residue; (3) filtering the upper liquid A obtained in the step (2) to obtain filtrate A; at the same time, adding water to the residue obtained in the step (2), shaking and centrifuging to obtain an upper liquid B, filtering the upper liquid B, and obtaining filtrate B; (4) combining the filtrate A and the filtrate B to obtain an extracting solution. The iodine inthe milk powder is extracted by the method of the invention, and during detection, the adding standard recovery is good; and the measuring accuracy is high.

Description

technical field [0001] The invention relates to an extraction method and a detection method, in particular to an extraction method and a detection method of iodine in milk powder. Background technique [0002] Iodine is one of the halogen elements. Elemental iodine is in the form of purple-black crystals and is easy to sublime. It is one of the essential trace elements for the human body. A series of diseases easily caused by iodine deficiency were previously named endemic goiter and endemic cretinism. Now collectively known as iodine deficiency disorders. At the same time, iodine is a "double-edged sword". Excessive iodine can lead to a significant increase in the incidence of hypothyroidism, autoimmune thyroid disease and papillary thyroid cancer. Therefore, the determination of iodine content in food is of great significance. Milk powder is a processed product of milk. Almost all the water in it has been removed. There are different formulas for different groups of peop...

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Problems solved by technology

Generally, the content of iodine in milk powder is 30-150 micrograms. The current national standard for the determination of iodine in milk powder includes the second method of spectrophotometry and the third method of gas chromatography in GB 5009.267-2016 "National Food Safety Standard for the Determination of Iodine in Food". , the third method replaces the old standard GB 5413.23-2010 "National Food Safety Standard for Determination of Iodine in Infant Foods and Dairy Products", but there is still no improvement in the old standard for the shortcomings of the old standard such as cumbersome operation and high standard recovery. The second method has the disadvantages of long-time sample drying and long-time sample carbonization and ashing; inductively coupled plasma mass spectrometry [3] The determination of iodine content is affected by the temperature and time of microwave digestion, which may easily lead to low recovery of standard addition; some people have also done research on gas chromatography, but the main research is on the optimization of derivation conditions and the optimization of instrument conditions or the verification of the method

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