CN101413894A - Iodine content on site rapid quantitative detection reagent in common salt added with iodine and preparation process thereof - Google Patents

Abstract

The invention discloses a field rapid quantitative detection reagent for testing iodine content in iodized salt and a preparation technology thereof. The reagent is made from ion exchange water, potassium iodide, starch, phosphoric acid, formamide and sodium thiosulfate. The testing reagent is prepared by potassium iodide solution, starch solution and sodium thiosulfate standard solution, and diluted by carbon dioxide-free water with various auxiliary reagents according to testing standard such as an upper limit and a lower limit of the iodine content in the iodized salt, judgment for detecting non-iodized salt, and the like, which are regulated by national standard, and then on-site testing can be carried out. The detection reagent, a weighing instrument and a reagent adding device, and like, are combined together to form a field quantitative detection kit for the iodized salt. The invention has the advantages of convenient carrying, simple testing, and is suitably applied to professional, amateur and residents.

Description

On-the-spot rapid quantitative detection reagent of content of iodine and preparation technology in the iodized salt

Technical field

The invention provides on-the-spot rapid quantitative detection reagent of content of iodine and preparation technology in a kind of iodized salt, relate to a kind of tool using that salt compounded of iodine is carried out on-the-spot detection, belong to the food safety detection technical field.

Background technology

At present, the in-situ check and test method of links such as domestic and international processing to the Potassiumiodate iodic salt, sale is the sxemiquantitative colourimetry, it is 50 or 100mg/kg that the fast detecting medicine box that the World Health Organization (WHO), United Nations Children's Fund, international control IDD (Iodine deficiency disorders) council are recommended can be surveyed Cmax, and degree of accuracy is ± 10mg/kg.Provinces such as the Jilin of China, Hebei, Hubei have also developed the sxemiquantitative color board or colourimetry is used, and its concentration gradient is 0,10,20,30,40.Above-mentioned each sxemiquantitative colourimetry is because the color range colourity of concentration gradient correspondence is little, degree of accuracy is little, makes the semiquantitative qualification rate of salt compounded of iodine almost up to 100%, only is 50-60% but detect qualification rate with the batch sample laboratory, cause the on-the-spot distortion that detects, had a strong impact on the prevention effect of IDD (Iodine deficiency disorders).

Summary of the invention

The invention provides the on-the-spot rapid quantitative detection reagent of content of iodine in a kind of iodized salt, provide the last lower threshold value place of content of iodine in reagent that can detect at the scene and the iodized salt that guarantees national formulation qualitatively to detect accurately and the detection of on-the-spot fast quantification.

The invention also discloses the preparation technology of above-mentioned detectable, be applicable to suitability for industrialized production.

The on-the-spot rapid quantitative detection reagent of content of iodine in the iodized salt disclosed by the invention, by every part of detectable is that 5ml calculates, and potassium iodide 12 ~ 13mg, soluble starch 0.5 ~ 5mg, phosphatase 11 2 ~ 18mg, formamide 0.01 ~ 0.03mg, sodium thiosulfate 0.2 ~ 0.5mg, ion exchange water are surplus.

The preparation technology of described detectable may further comprise the steps:

Preparation 5 ~ 10% potassium iodide aqueous solutions (W/V);

Preparation 0.5 ~ 1.0% amidin (W/V); Get soluble starch water furnishing pasty state, pour in the ion exchange water that boils, boil again after 20-30 seconds immediately with being water-cooled to room temperature;

The preparation sodium thiosulfate standard solution; 0.002 mol;

Get and demarcate good sodium thiosulfate standard solution and add respectively by 0.5 ~ 1.0% starch, 85% phosphoric acid, 5 ~ 10% potassium iodides and formamide by required variable concentrations standard and do in the in situ quantitation detectable of end liquid, to 50,20,5ug/ml concentration is as salt compounded of iodine in situ quantitation detectable, is rig-site utilization reagent after the packing.

Threshold test:

The present invention in use, the detectable of preparation is detected the requirement of decision content (5mg/kg) by higher limit (50mg/kg), lower limit (20mg/kg), the Non-iodizedsalt of the determination of iodine in iodized salt content of national regulation, be the critical concentration value with 10/ugml, 4ug/ml, 1ug/ml respectively, all get 5ml respectively and be placed in the tool plug reaction bulb and preserve, as the detection threshold of above-mentioned three kinds of variable concentrations salt compounded of iodine.This reagent is colourless transparent liquid, when carrying out the scene detection, the tested salt compounded of iodine sample of one gram is put into the corresponding detection liquid that requires that detects observe change color: put into the Non-iodizedsalt detectable, as being Non-iodizedsalt as no change color then into containing salt compounded of iodine by the blue look of colourless change; Put into the lower limit detectable, as becoming blue look by colourless, then salt compounded of iodine content is higher than the lower limit requirement of 20mg/kg, for Qualified iodized salt such as nondiscolouring then for not reaching the lower limit requirement, content of iodine is defective; Put into upper limit reagent, as becoming blue look by colourless, then to surpass state specified standards be defective salt compounded of iodine to content of iodine, as nondiscolouring then content of iodine be Qualified iodized salt above 50mg/kg with ing.

Detection by quantitative:

Get 1.00 gram salt compounded of iodine and put in 5-10ml transparent plastics or vial with cover, add salt compounded of iodine Quantitative Monitoring reagent to color continuously with quantitative charger and only just become colorless by blue look.Record consumes the milliliter number of this reagent, will move a content of iodine concentration (unit: 1:ml/kg) that is this monitored salt compounded of iodine sample behind the radix point.

The present invention can be contained in the case by different detectable concentration requirements respectively, is equipped with weighing (as balance) and liquid reagent adding equipment (as sample injector, transfer pipet etc.) and can forms the in situ quantitation detection case, is easy to carry and on-the-spot the use.

Good effect of the present invention is the standard that detects the critical value of variable concentrations such as guaranteeing national determination of iodine in iodized salt content upper and lower limit of formulating and Non-iodizedsalt judgement at the scene to be carried out the scene detect, and carries out in situ quantitation on the basis of detecting at the scene and detect.

Embodiment

For the ease of understanding the present invention, especially exemplified by following examples.Its effect is understood that it is to explaination of the present invention but not to any type of restriction of the present invention.

Embodiment 1

Take by weighing potassium iodide, starch, phosphoric acid, sodium thiosulfate, deionized water and formamide in proportion,

Prepare 5% potassium iodide aqueous solution (W/V);

Prepare 0.5% amidin:

Get 0.5 gram soluble starch water furnishing pasty state, pour 100ml into and boil in the deionized water, boil again after 20-30 seconds immediately with being water-cooled to room temperature;

The preparation hypo solution:

Getting 5 gram sodium thiosulfate is dissolved in the 1000ml carbon dioxide-free water, store in the brown bottle, leave standstill a week, get supernatant 200ml and add 0.2 gram sodium carbonate, the dissolving back is settled to 2000ml with carbon dioxide-free water, draw 10.00ml and add 0.002 equivalent potassium iodide standard solution in the 250ml iodine flask, add water 90ml, 85% phosphatase 11 .0ml, shake up the back and add the 5ml liquor kalii iodide, demarcate with hypo solution immediately, when solution shows light yellow, add the 5ml0.5% starch solution, till continuation titration to blue look disappears just, calculate titer;

Get and demarcate good sodium thiosulfate standard solution and add respectively by 0.5 ~ 1.0% starch, 85% phosphoric acid, 5 ~ 10% potassium iodides and formamide by required variable concentrations standard and do in the in situ quantitation detectable of end liquid, to 50,20,5ug/ml concentration is as salt compounded of iodine in situ quantitation detectable, is rig-site utilization reagent after the packing.

Embodiment 2

By every part of detectable is that 5ml calculates, outside the deionization exchanged water, also have following material: potassium iodide 12.5mg, starch 1.25mg, phosphatase 11 2.75mg, formamide 0.01mg, sodium thiosulfate 0.2-0.5mg form, and its technology is preparation 5% potassium iodide aqueous solution (W/V); Prepare 0.5% amidin (get 0.5 gram soluble starch with low amounts of water furnishing pasty state, pour 100ml into and boil in the deionized water, boil again after 20-30 seconds) immediately with being water-cooled to room temperature; (get 5 gram sodium thiosulfate is dissolved in the 1000ml carbon dioxide-free water preparation hypo solution, store in the brown bottle, leave standstill a week, get supernatant 200ml and add 0.2 gram sodium carbonate, the dissolving back is settled to 2000ml with carbon dioxide-free water, draw 10.00ml and add 0.002 mole of potassium iodide standard solution in the 250ml iodine flask, add water 90ml, 85% phosphatase 11 .0ml, shake up the back and add the 5ml liquor kalii iodide, demarcate with hypo solution immediately, when solution shows light yellow, add the 5ml0.5% starch solution, till continuation titration to blue look disappears just, calculate titer); Get and demarcate good sodium thiosulfate standard solution and add respectively by 0.5% starch, 85% phosphoric acid, 5% potassium iodide and formamide by required variable concentrations standard and do in the in situ quantitation detectable of end liquid, to 50,20,5ug/ml concentration is as salt compounded of iodine in situ quantitation detectable, is rig-site utilization reagent after the packing.

Embodiment 3

Prepare 10% potassium iodide aqueous solution (W/V);

Prepare 1.0% amidin (W/V); Get soluble starch water furnishing pasty state, pour in the ion exchange water that boils, boil again after 20-30 seconds immediately with being water-cooled to room temperature;

The preparation sodium thiosulfate standard solution; 0.002 mol;

Get and demarcate good sodium thiosulfate standard solution and add respectively by 1.0% starch, 85% phosphoric acid, 10% potassium iodide and 0.03mg formamide by required variable concentrations standard and do in the in situ quantitation detectable of end liquid, to 50,20,5ug/ml concentration is as salt compounded of iodine in situ quantitation detectable, is rig-site utilization reagent after the packing.

Claims (2)

1, the on-the-spot rapid quantitative detection reagent of content of iodine in a kind of iodized salt, make by following raw material:

By every part of detectable is that 5ml calculates, and potassium iodide 12 ~ 13mg, soluble starch 0.5 ~ 5mg, phosphatase 11 2 ~ 18mg, formamide 0.01 ~ 0.03mg, sodium thiosulfate 0.2 ~ 0.5mg, ion exchange water are surplus.

2, the preparation technology of the described detectable of claim 1 may further comprise the steps:

Preparation 5 ~ 10% potassium iodide aqueous solutions (W/V);

Preparation 0.5 ~ 1.0% amidin (W/V); Get soluble starch water furnishing pasty state, pour in the ion exchange water that boils, boil again after 20 ~ 30 seconds immediately with being water-cooled to room temperature;

The preparation sodium thiosulfate standard solution; 0.002 mol;

Get and demarcate good sodium thiosulfate standard solution and add respectively by 0.5 ~ 1.0% starch, 85% phosphoric acid, 5 ~ 10% potassium iodides and formamide by required variable concentrations standard and do in the in situ quantitation detectable of end liquid, to 50,20,5ug/ml concentration is as salt compounded of iodine in situ quantitation detectable, is rig-site utilization reagent after the packing.