Sample pretreatment method simultaneously determining arsenic and mercury in milk and dairy products and detection method using same

A sample pretreatment and dairy product technology, applied in the preparation of test samples, fluorescence/phosphorescence, material excitation analysis, etc., can solve the problems of cost, manpower and material resources, etc., achieve accurate test results, save test costs, arsenic and The effect that the loss of mercury element is small

Inactive Publication Date: 2015-11-25
INNER MONGOLIA MENGNIU DAIRY IND (GRP) CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] Therefore, to detect arsenic and mercury in milk and dairy products, samples need to be pretreated separately, which consumes a lot of manpower and material resources

Method used

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  • Sample pretreatment method simultaneously determining arsenic and mercury in milk and dairy products and detection method using same

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0022] 1 Main instruments and reagents.

[0023] 1.1 Instrument

[0024] Jitian Atomic Fluorescence Photometer; High Performance Arsenic Hollow Cathode Lamp; High Performance Mercury Hollow Cathode Lamp; American CEI Microwave Digestion Equipment.

[0025] 1.2 Reagents

[0026] Mercury standard stock solution: 1mg / L, National Center for Standard Materials; arsenic standard stock solution: 1mg / L, National Center for Standard Materials; Urea; saturated sodium hydroxide solution; all the utensils in the experiment were soaked in (1:1) nitric acid solution overnight, then rinsed with distilled water and ultrapure water, and then dried for later use; the water used in the experiment was ultrapure water (with a resistance value greater than 18.2MΩ).

[0027] 2 Instrument working conditions

[0028] Photomultiplier tube negative high voltage 240mV; mercury lamp current 30mA; arsenic lamp current 60mA; atomizer height 10mm carrier gas flow 400mL / min; shielding gas flow 1000mL / min;...

Embodiment 2

[0041] In this example, the sample pretreatment method is adjusted on the basis of Example 1, and the rest of the method steps are the same as in Example 1.

[0042]Sample pretreatment: Weigh the milk beverage to be tested in the digestion tank, the sampling volume is 1.0g, add 2mL hydrogen peroxide (30% by mass fraction) and 4mL nitric acid (65.0% to 68.0% by mass fraction) to obtain the Digestion solution: place the solution to be digested in the microwave digestion equipment, and digest it according to the set procedure (see Table 1 in Example 1). After the digestion is completed and cooled to 25-30°C, add 1.0mL saturated sodium hydroxide solution to obtain neutralization solution; transfer the neutralizing solution to a 25mL volumetric flask with a volume fraction of 5% hydrochloric acid solution, then add 2.5mL of 50g / L thiourea solution, and use a volume fraction of 5% hydrochloric acid solution to dilute to 25mL and mix to obtain Liquid to be tested. At the same time a...

Embodiment 3

[0045] In this example, the sample pretreatment method is adjusted on the basis of Example 1, and the rest of the method steps are the same as in Example 1.

[0046] Sample pretreatment: Weigh the milk powder of the sample to be tested in the digestion tank, the sampling volume is 0.3g, add 2mL of hydrogen peroxide (30% by mass fraction) and 4mL of nitric acid (65.0% to 68.0% by mass fraction) to obtain the digested solution; place the solution to be digested in the microwave digestion equipment, and digest it according to the set program (see Table 1 in Example 1). It is that 5% hydrochloric acid solution is transferred in the 25mL volumetric flask by neutralizing solution with volume fraction, then adds the thiourea solution of 2.5mL50g / L, is that 5% hydrochloric acid solution is settled to 25mL and mixes with volume fraction, obtains measuring liquid. At the same time as a blank control.

[0047] The correlation coefficients of the standard curve are: the correlation coef...

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Abstract

The invention provides a sample pretreatment method simultaneously determining arsenic and mercury in milk and dairy products. The method comprises weighing 0.3-1.0 g of to-be measured milk or dairy product in a digestion tank, adding 2.0 mL of hydrogen peroxide and 4.0 mL of nitric acid, so as to obtain a to-be digested solution, wherein the mass fraction of hydrogen peroxide is 30%, and the mass fraction of nitric acid is 65.0%-68.0%; performing microwave digestion on the to-be digested solution; cooling the solution obtained after microwave digestion, adding 1.0 mL of a saturated sodium hydroxide solution, so as to obtain a neutralization solution; and transferring the neutralization solution to another container by using hydrochloric acid, then adding 2.5 mL of a thiourea solution with the concentration of 50 g/L, finally using a hydrochloric acid solution to set a constant volume of 25 mL, and uniformly mixing the solution. The process does not need acid expelling, the sample can be completely digested, and loss of arsenic and mercury elements is relatively small. By using the sample pretreatment method for detection, the detection result is relatively accurate.

Description

technical field [0001] The invention relates to a sample pretreatment method for determining elements in milk and dairy products and a detection method using the method, and is especially suitable for simultaneously detecting the arsenic and mercury contents in milk and dairy products. Background technique [0002] At present, when detecting arsenic and mercury in milk and dairy products, different pretreatments are required for the samples. The following are common sample pretreatment methods for the detection of arsenic and mercury. [0003] Sample pretreatment method for detection of arsenic: Weigh 0.3g-1g of sample (milk and dairy products), add 4mL superior pure nitric acid and 2mL superior pure hydrogen peroxide in sequence to the microwave digestion tube, tighten the microwave digestion tube cap, Place it in a microwave digestion apparatus, start digestion according to the temperature program, cool down after digestion, place it on a temperature-controlled heater to d...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G01N1/44G01N21/64
Inventor 乌尼尔满都呼高娃其其格常建军宋晓东
Owner INNER MONGOLIA MENGNIU DAIRY IND (GRP) CO LTD
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