Other physical and chemical testing parameters detection

This standard specifies the determination method for nitrite and nitrate in food. This standard is applicable to the determination of nitrite and nitrate in food. After precipitation of protein and removal of fat, the sample was extracted and purified using corresponding methods. Potassium hydroxide solution was used as the eluent, and anion exchange column was used for separation. Conductivity detector or UV detector was used for detection. Qualitative analysis based on retention time and quantitative analysis using external standard method. Unless otherwise specified, all reagents and materials used in this method are analytical pure, and the water is the first grade water specified in GB/T 6682. 3.1 Reagent 3.1.1 Acetic acid (CH, COOH). 3.1.2 Potassium hydroxide (KOH). 3.2 Reagent Preparation 3.2.1 Acetic Acid Solution (3%): Measure 3 mL of acetic acid into a 100 mL volumetric flask, dilute with water to the mark, and mix well. 3.2.2 Potassium hydroxide solution (1 mol/L): Weigh 6 g of potassium hydroxide, dissolve in freshly boiled cold water, dilute to 100 mL, and mix well. 3.3 Standard substance 3.3.1 Sodium nitrite (NaNO, CAS No. 7632-00-0): Reference reagent, or nitrite standard solution with a standard substance certificate. 3.3.2 Sodium nitrate (NaNO, CAS No. 7631-99-4): Reference reagent, or nitrate standard solution with a standard substance certificate. 3.4 Preparation of Standard Solution 3.4.1 Nitrite Standard Stock Solution (100 mg/L, calculated as NO.): Accurately weigh 0.150 0g of sodium nitrite dried to constant weight at 110 ℃~120 ℃, dissolve in water, transfer to a 1000 mL volumetric flask, dilute to volume with water, and mix well. 3.4.2 Nitrite Standard Stock Solution (1000 mg/L, calculated as NO., same below) Accurately weigh 1.371 0g of sodium nitrate dried to constant weight at 110 ℃~120 ℃, dissolve in water, transfer to a 1000 mL volumetric flask, dilute with water to the mark, and mix well. 3.4.3 Nitrite and nitrate mixed standard intermediate solution: Accurately transfer 1.0 mL of standard stock solutions for nitrite ion (NO.) and nitrate ion (NO.) into a 100 mL volumetric flask, dilute with water to the mark, and this solution contains 1.0 mg of nitrite ion and nitrate acid per liter

Function of testing report:

1. Project bidding: Issue authoritative third-party CMA/CNAS qualification report

2. Online e-commerce platform entry: Quality inspection report recognized by major e-commerce platforms

3. Used as a sales report: issuing legally effective testing reports to make consumers more confident

4. Papers and research: Provide professional personalized testing needs

5. Judicial services: providing scientific, fair, and accurate testing data

6. Industrial problem diagnosis: Verify the troubleshooting and correction of industrial production problems

BAIJIAN testing process:

1. Telephone communication and confirmation of requirements

2. Recommend solutions and confirm quotations

3. Mail samples and arrange testing

4. Progress tracking and result feedback

5. Provide reports and after-sales service

6. If urgent or priority processing is required

Our Competitive Edge:

1. The testing industry is fully covered, meeting different testing needs

2. Fully cover the laboratory and allocate localized testing nearby

3. Engineers provide one-on-one services to make testing more accurate

4. Free initial testing, with no testing fees charged

5. Self service order delivery for free on-site sampling

6. Short cycle, low cost, and attentive service

7. Possess authoritative qualifications such as CMA, CNAS, CAL, etc

8. The testing report is authoritative and effective, and is generally used in China