Limits and determination method of certain toxic elements in printing ink Part 2:lead、mercury、cadmium、chromium
Some standard content:
1CS 87.080
Classification number: A17
Registration number: 233BB-200B
Light Industry Standard of the People's Republic of China
QB 2930.2—2008
Limits and determination method of certain toxic elements in printing inkPart2:lead、mercury、cadmium、chromium (VI)2008-02-01 Issued by
National Development and Reform Commission of the People's Republic of China on 2008-07-01 Implementation
All technical contents of this part are mandatory. Foreword
QB2930 "Limits of Certain Harmful Elements in Oils and Their Determination Methods" is divided into two parts: - Part 1: Movable Elements;
- Part 2: Lead, lead, chromium, hexavalent chromium. This part is the second part of QB2930.
Appendix A of this part is a normative appendix.
This part was proposed by China Light Industry Federation. This part is under the jurisdiction of the National Technical Committee for Printing Ink Standardization. QB2930.2-2008
The drafting units of this part are: National Quality Supervision and Inspection Center for Printing and Decorating Products, Beijing Youwei Technology Co., Ltd., Tianjin Dongyang Oil Wall Co., Ltd., Shanghai Mudan Oil Equipment Co., Ltd., Tianjin Tiannv Chemical Group Co., Ltd., Hanghua Ink Chemical Co., Ltd., Yip's Ink (Zhongshan) Co., Ltd., Taiyuan Gao's Lowry Ink Chemical Co., Ltd., Shanghai Shanmo Silian Chemical Co., Ltd., Shanghai DIC Shanmo Co., Ltd., Haiyan Huada Ink Chemical Co., Ltd., Ink/Coating Center of Polymer Research Institute, School of Chemistry, Sun Yat-sen University. The main drafters of this part are: Su Chuanjian, Liu Dewen, Zhou Mei, Fang Anguo, Du Zhongjiang, Huang Chaihai, Wu Shaotang, Gao Yongfeng, Li Mingyu. Chai Dai, Zhang Yuecheng, Wang Xiaomei.
This part is published for the first time.
1 Scope
Limits of certain harmful elements in ink and their determination methods Part 2: Lead, mercury, cadmium, hexavalent chromium
This part specifies the limit requirements, sample preparation and determination methods for lead, cadmium, mercury and hexavalent chromium in ink. This part is applicable to printing ink products, and printing ink printed products can be used according to the instructions. 2 General Principles
This part is the general technical requirements for the production and use safety of printing ink products. QB2930.2—2008
This part aims to protect human life and health to the greatest extent possible, reduce pollution and damage to the environment, and should not harm the safety or health of users or third parties.
3 Technical requirements
The total content of lead, mercury, mercury and hexavalent chromium shall not exceed 100mg/kg. 4 Methods and Methods
For ink products and oil-based printed products, the digestion method is directly used for sample pretreatment, and then the digestion solution is introduced into a flame atomic absorption spectrophotometer, an atomic fluorescence spectrophotometer or an 1CP inductively coupled plasma atomic emission spectrophotometer to detect lead, chromium and mercury. The water-soluble and water-insoluble hexavalent chromium compounds in the sample are leached out using an alkaline leaching solution. The hexavalent chromium in the leaching solution reacts with diphenylcarbonyl dihydroxide in an acidic solution to form a purple-red complex, which is measured by spectrophotometry at a wavelength of 540nm. 5 Sample Preparation
5. 1 Ink
5.1.1 Test Sample Sampling Procedure
After the sample is stirred evenly, a coating is prepared on a glass plate, and a sample is taken after it is completely dried (if dried, the temperature should not exceed 80°C), crushed at room temperature, and sieved through a 0.5mm metal sieve for processing. Method: If the coating is not easy to powder and the silica content is 0.5m, the sample can be processed directly without sieving. 5.1.2 Sample digestion
5.1.2.1 Pressure tank digestion method
Weigh 0.5g of the sample, place it in a pressure tank, add 8mL of nitric acid, 2ml of 30% hydrogen peroxide, and for materials containing more silica such as glass and ceramics, add 3mL of hydrogen peroxide. Cover with tetrafluoroethylene, tighten the stainless steel tank jacket, place it in an oven, and heat it at (180+5)℃ for 4h. After the pressure tank cools to room temperature, transfer the digestion solution to a 100mL volumetric flask, wash the polytetrafluoroethylene liner and cover with ice 3 to 4 times, transfer the washing solution to a volumetric flask, and dilute with water to the scale. If the solution is not clear or precipitation is produced, filter and retain the filter to be tested. Perform a reagent blank test at the same time. 5.1.2.2 Other digestion methods
Other digestion methods such as acid-wet digestion and decomposition can be used to treat samples and samples that cannot be completely digested by the method in 5.1.2.1.
5.2 Printed products with ink
QB2930.2—2008
If the ink coating on the printed matter can be removed separately, the test sample shall be digested according to 5.1.2: If the ink coating on the printed matter cannot be removed separately, it shall be treated according to 5.2.1
5.2.1 Sample treatment
In this case, the test sample is directly extracted from the printed matter so that the test sample also includes a representative sample of the coating area, and 1.0g of the removed test sample is digested according to 5.1.2. 6 Test Methods
6.1 Test Methods for Lead
6.1.1 Reagents and Materials
Unless otherwise specified, only reagents and distilled or deionized water or water of equivalent purity that are confirmed to be analytical grade or higher shall be used in the analysis. 6.1.1.1 Nitric Acid (HNO3): Premium Grade. 6.1.1.2 Nitric Acid Solution: (1INO3) =(0.5±0.005) mol/L6.1.1.3 30% Hydrogen Peroxide (H2O2): Analytical Grade. 6.1.1.4
Hydrochloric Acid (HCl): Premium Grade.
6.1.1.6
Hydrofluoric acid (HP): high purity,
lead and cadmium standard solution: concentration of 100mng/L or 1000mg/L, 6.1.2 Instruments and equipment
flame atomic absorption spectrophotometer: suitable for the measurement of heavy metals to be measured, and equipped with a burner that can be passed through acetylene and air.
6.1.2.1
6.1.2.2 Element spectrum source: lead hollow cathode lamp, hollow cathode lamp 6.1.2.3 Oven: 0℃~200℃, temperature control accuracy ±5℃. 6.t.2.4 Pressure tank: tetrafluoroethylene liner and stainless steel tank jacket. 6.1.2.5 Electric heating plate (for acid wet digestion method) or muffle furnace (for ashing method). 6.1.3 Drawing working curve and determination
Dilute the lead and steel standard solutions step by step with 0.5mol/L nitric acid solution to prepare the following standard solution series: cobalt: 0, 1.0, 2.0, 3.0, 5.0, 10.0mg/L; cobalt: 0, 0.1, 0.2, 0.3, 0.5, 1.0 mg/L. Use flame atomic absorption spectrophotometer to measure the absorbance of the standard solution, and use the concentration of lead and steel standard reference solution (in ug/mL) as the abscissa and the corresponding absorbance value minus the absorbance value of the blank test solution as the ordinate to draw the curve, and measure the absorbance of the digestion solution at the same time. If the lead and steel concentrations exceed the concentration value at the highest point of the working curve, the paired digestion solutions should be appropriately diluted before determination. According to the working curve and the absorbance value of the digestion solution, the instrument automatically gives the concentration value of the element to be measured in the digestion solution. 6.1.4 Result calculation
The content of lead and lead in the sample is expressed as mass fraction w, and the value is expressed in milligrams per dry gram (mg/kg). It is calculated according to formula (1): e×V×N
Wherein:
The content of lead and lead in the sample, in milligrams per kilogram (mg/kg); The measured concentration of the sample digestion solution, the median is milligrams per liter (mg/L); The volume of the digestion solution, in milliliters (mL): N---The dilution factor of the digestion solution:
The mass of the sample, in grams (g). 6.2 Test method for mercury
6.2. 1 Reagents
QB 2930.2-2008
Unless otherwise specified, only reagents of analytical grade or above and distilled water or deionized water or water of equivalent purity shall be used in the analysis. 6.2.1.1 Nitric acid (HNO3): high purity. 6.2.1.2 Nitric acid solution: c(HNO3) = (0.5±0.005) mol]/L. 6.2.1.3 30% hydrogen peroxide: analytical grade. Hydrochloric acid (HCl): high purity.
6. 2. 1. 4
Hydrofluoric acid: analytical grade.
6. 2. 1. 5
6. 2. 1. 6
6. 2. 1.7
Sodium hydroxide: analytical grade:
Sodium hydroxide solution (5g/L): weigh 5.0g sodium hydroxide, dissolve in water, dilute to 1000mL, mix well. Sodium borohydride (NaBH4): analytical grade
6. 2. 1. 8
6. 2. 1. 9
Use immediately.
Sodium hydride solution (0.2g/L): weigh 0.1g sodium borohydride and dissolve in 500mL sodium hydroxide solution, mix well, and prepare the 6.2.1.10 mercury standard stock solution: concentration 1mg/mL. Calculate the standard working solution: concentration 0.5u/mL, dilute step by step with the mercury standard stock solution, and make up to volume with nitric acid solution. 6.2.1.11
6.2.2 Instruments and equipment
6.2.2.1 Atomic fluorescence photometer: equipped with a hollow cathode lamp, the instrument's detection line for mercury should reach 2.0ng/mL. 6.2.2.2 Oven: 0℃～200℃, temperature control accuracy ±5℃6.2.2.3 Pressure tank: polytetrafluoroethylene liner and stainless steel jacket. 6.2.2.4 Electric heating plate. bZxz.net
6.2.3 Standard solution series configuration
Respectively transfer 0.0, 0.2, 0.4, 0.6, 0.8, 1.0mL of water standard solution into a set of 50mL volumetric bottles, dilute to the scale with nitric acid solution, and mix well. The concentrations of the standard solution series are 0.0, 2.0, 4.06.0, 8.0, 10.0mg/mL respectively. The reference solution of the solution should be prepared on the day of use.
6. 2. 4 Plotting the curve
Measure the fluorescence intensity of the standard solution and the sample at the same time, and plot the curve with the concentration of the standard reference solution (in ng/mL) as the horizontal axis and the corresponding absorbance value minus the absorbance value of the blank test solution as the vertical axis. 6. 2. 5 Determination and result calculation
Measure the fluorescence intensity of the digestion solution with an atomic fluorescence spectrophotometer, and calculate the concentration of the solution of the solution of the solution according to the standard curve. If the concentration of the solution of the solution of the solution exceeds the concentration value of the highest point of the standard curve, the solution of the solution should be appropriately diluted before determination. The content of the substance in the test mix is expressed as mass fraction w, and the value is expressed in grams per kilogram (mg/kg), calculated according to formula (2): cxV×Nx10-
Wherein:
The content in the sample, in milligrams per gram (mgkg); The concentration of the sample calculated from the standard curve, in nanograms per milliliter (g/mL); V\--The volume of the digestion solution, in milliliter (mL); N--The dilution factor of the digestion solution:
The weight of the sample, in (),
Note: It is recommended to use ICP-MS (inductively coupled plasma atomic emission spectrophotometer mass spectrometry) for detection during arbitration inspection. 6.3 Test method for hexavalent chromium in oil
Hexavalent chromium in ink shall be tested in accordance with the Appendix (Normative Appendix). 7 Test report
The test report shall at least include the following contents:..(2)
QB2930.2-2008
a) Name of the product under test;
b) Test basis or test method;
c) Correction value of the elemental analysis result, expressed in mg element/kg material, and a statement that this test result is the content of the element in the solution:
Experimental results;
|) Any experimental conditions that deviate from the test basis;
|f) Differences from the prescribed test procedures due to agreement or other reasons;
z) Test date;
h) Test instruments.
A.1 Scope
Appendix A
(Normative Appendix)
Test Method for Hexavalent Chromium
This appendix specifies the limit requirements, sample preparation and test methods for hexavalent chromium in oil containers. This appendix applies to ink products and to ink printed products. A.2 Reagents and Materials
QB 2930.2—2008
Unless otherwise specified, reagents and distilled water or deionized water or water of equivalent purity that are confirmed as analytically pure shall be used in the analysis. A.2.1 Nitric Acid: Superior Grade.
A.2.2 Sulfuric Acid: Superior Grade.
Sodium Hydroxide.
Anhydrous Sodium Carbonate.
A.2. 5 Dipotassium Hydrogen Phosphate.
Potassium Dihydrogen Phosphate.
Potassium Dichromate: Reference Material.
Monophenylcarbazide.
Acetone.
Sulfuric acid solution (1+9) (volume fraction). Nitric acid solution (5mol/L): Measure 31mL nitric acid and add it to 69mL water, mix. Nitric acid with brown smoke should not be used for preparation. A.2.12 Extract: Weigh 20.0g sodium hydroxide and 30.0g anhydrous sodium carbonate, dissolve them in water, transfer to a 1000mL volumetric flask and dilute to the mark, shake well, and transfer to a plastic bottle for storage. A.2.13 Buffer solution: dissolve 87.09g potassium dihydrogen phosphate and 68.04g potassium dihydrogen phosphate in water, transfer to a 1000mL volumetric flask and dilute to scale with water (this buffer solution has a pH of -7).
A.2.14 Hexavalent chromium standard stock solution, 100mg/L: accurately weigh 0.2828g potassium dichromate dried at 120℃ for 2h, dissolve it in water and transfer to a 1000mL volumetric flask, dilute to scale with water, and operate. A.215 Hexavalent chromium standard solution, 5.0mg/L: aspirate 5.0mL of standard stock solution in a 100mL volumetric flask, dilute to scale with water, and spread evenly. Prepare it when needed.
A.2.16 Diphenylcarbohydrazide (DPC) color developer: weigh 0.5g diphenylcarbohydrazide and dissolve it in [00rL of acetone, and store it in a brown bottle. When the solution fades, it should be re-prepared.
A.3 Instruments and equipment
A.3.1 UV spectrophotometer.
A.3.2 Oscillating water bath.
A. 3.3 Acidity meter.
A. 4 Analysis steps
A, 4.1 Sample preparation
A, 4.1.1 Ink
QB2930.2-2008
After stirring the sample evenly, prepare the coating on the glass plate, wait for it to be completely dried, take the sample (the temperature should not exceed 80℃ for drying), crush it at room temperature, and sieve it through a 0.5mm metal sieve for processing. Note: If the coating is not easy to be crushed into 0.5mm, it can be directly processed without sieving. A.4.1.2 Ink Prints
If the ink coating on the printed matter can be removed separately, the oil coating shall be removed and crushed at room temperature, and then sieved through a 0.5mm metal sieve for further processing. If the oil coating on the printed matter cannot be removed separately, in this case, the test sample shall be directly extracted from the printed matter so that the test sample also includes a representative sample of the coating area, and the sample shall be processed into a sample with a diameter not exceeding 1mm and a length not exceeding 5mm. A.4.2 Sample Extraction
Accurately weigh 0.5g of sample into a conical flask, add 25mL of extracting solution and 10.5mL of buffer solution, and completely cover the sample with the extracting solution, and shake thoroughly. Stir continuously in a water bath (or shaking water bath) at 90-95℃ for 1.5h. Take out, cool to room temperature, filter, wash the sample in the conical flask with water, and collect the filtrate and washing solution in a beaker. Add 5 mol/L nitric acid and use an acidometer to control the pH of the bath solution at 7.5+0.5. If flocculent precipitation occurs, filter again and keep the filtrate. Perform a reagent blank test at the same time. A.4.3 Color development
Add 2.0 rmL of diphenylcarbonyl dithiocyanate color developer to the filtrate, mix well, add sulfuric acid solution to make the pH of the filtrate reach 2±0.5, then transfer all the filtrate to a 100 mL volumetric flask and dilute with water to fill the mark. Shake the hook and leave for 0.5 h. A. 4. 4 Standard solution
Pipette 0.0, 2.0, 4.0, 6.0, 8.0, 10.0mL of hexavalent chromium standard solution into a 100mL container, add 50mL of water, add 2.0mL of color developer, mix, add 2 drops of sulfuric acid solution to make the pH of the filtrate reach 2+0.5, dilute with water to the scale, this standard series contains hexavalent chromium concentrations of 0.0, 0.1, 0.2, 0.3, 0.4, 0.5mg/L, use a spoon to mix well, place 0.5ha, and the color development reaction of the standard solution and the leaching solution should be carried out at the same time. A. 4. 5 Determination
Use a 1cm absorption cell and measure the absorbance value of the standard solution with a UV-visible spectrophotometer at an absorption wavelength of 540mm, and draw a standard curve with the absorbance value corresponding to the concentration value.
Read the absorbance of the sample leaching solution under the same conditions, and calculate the hexavalent chromium concentration in the leaching solution according to the standard curve. If the absorbance of the leaching solution exceeds the absorbance of the highest concentration point of the standard curve, the leaching solution should be appropriately diluted before measurement. The solution after color development should be measured when the measurement is completed.
A.4.6 Result calculation
The hexavalent chromium content in the sample is expressed as mass fraction w, and the value is expressed in milligrams per kilogram (mg/kg). It is calculated according to formula (A.1): (AB)×VxN
Wherein:
Concentration of hexavalent chromium in the sample, in milligrams per gram (mg/kg): A——Liquidity of the leaching solution calculated from the standard curve, in milligrams per liter (mg/L): B-Concentration of the blank solution calculated from the standard curve, in milligrams per liter (ml); V-Volume of the leaching solution, in milliliter (mL): Dilution factor of the digestion solution:
Pre--Weighing mass of the sample, in grams (grams). 6
1. GB 6675
National Technical Specification for Safety of Toys
References
2.GB/T 6682 Specifications and test methods for analytical laboratories 3.SN/T 2004.1 Determination of mercury in electronic and electrical products Part 1: Atomic fluorescence spectrometry
QB2930.2-2008
Determination of lead, radium and chromium in electronic and electrical products Part 2: Flame atomic absorption spectrometry 4. SN/T 2004.2
5. SN/T 2004.3
Determination of hexavalent chromium in electronic and electrical products Part 3: Monocarbonyl dichromate spectrophotometry 7
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