[This article is the original article of Lefeng RephiLe company, please indicate the reprint, offenders. 】
"Grape wine wine luminous cup, want to drink immediately urge." When Emperor Wu of the Han Dynasty, Zhang Yutong Western Region, open up the Silk Road. Grapes and wines were introduced to China. Since then, regardless of the Han, Jin, Tang and Song Dynasties, wine is a favorite wine of the Chinese people. From 2013 to 2018, China's domestic wine consumption has remained above 1.5 million liters per year, exceeding 10% of global consumption. With the continuous advancement of the Belt and Road construction, China and Central Asia, Europe and other wine producing countries are also getting closer. It is foreseeable that the consumption of Chinese wine will continue to grow in the future.
The International Organization of Grapes and Wines (OIV) is an intergovernmental international organization of grape and wine producing countries that meet certain standards. OIV conducts a series of work to coordinate wine trade among member states, discuss research results, and develop technical standards that are consistent with international wine development trends. At present, the internationally accepted is the full-scale brewing regulations and inspection standards of the International Viticulture and Wine Organization (OIV) promulgated by the OIV in 2003. The regulations give limits and detection methods for the physical, chemical, and microbiological requirements of wine. The chemical requirements include two major categories of organic and inorganic substances, including organic sugars, alcohols, organic acids, gases and other organic substances. The inorganic substances are classified into anionic, cationic and non-metallic.
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In 2006, China introduced the National Standards for Wine of the People's Republic of China (GB/T 15037-2006) with reference to the above OIV standards. The standard specifies the definition, classification, requirements and analytical methods of wine. In the “Physical and Chemical Requirements†in the requirements, the standard imposes restrictions on the items described in Table 1:
Table 1 Physical and chemical requirements of the national standard of wine of the People's Republic of China
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With the continuous increase of domestic wine consumption and the awareness of food safety among Chinese people, the safety inspection of wine has become a routine requirement. Many regions have established professional wine testing laboratories to carry out different wine brands at home and abroad. Detection and analysis provide consumers with professional protection in accordance with China's safety and health regulations. In addition to routine testing, these laboratories are usually equipped with leading domestic laboratory pure water equipment, HPLC, GC and atomic absorption spectrometer (AAS) to detect additives, drug residues and lead in wine. A variety of heavy metals such as iron and copper and pathogenic microorganisms.
Here, Shanghai Lefeng (RephiLe) provides you with the detection methods and experimental schemes for heavy metal elements (iron, copper) in wine:
First, the experimental method
Atomic absorption spectrophotometry (AAS)
Second, instruments and reagents
Atomic absorption spectrophotometer (with iron hollow cathode lamp, copper hollow cathode lamp), Genie G ultra pure water system
Nitric acid solution (0.5%), iron standard solution (100 μg/mL), copper standard solution (100 μg/mL)
Third, the test method
Iron content detection
1, sample solution preparation
The sample was diluted 10 times with a nitric acid solution, shaken, and set aside.
2, iron standard series solution preparation
Pipette 0.00 mL, 1.00 mL, 2.00 mL, 4.00 mL, 5.00 mL of iron standard solution into five 100 mL volumetric flasks, and dilute to volume with nitric acid solution to obtain 0.0 μg, 10.0 μg, 20.0 μg, 40.0 μg, 50.0. Gg of iron standard series solution.
3, the standard curve
The atomic absorption spectrophotometer was equipped with an iron hollow cathode lamp, and the wavelength was adjusted to 248.3 nm. The absorbance of the iron standard series solution was measured, and a regression equation was established.
4, sample determination
The prepared sample solution was injected, the absorbance was measured, and then the iron content A was calculated according to the regression equation.
5, the result of calculation
The iron content in the sample is calculated according to the following formula:
X = A × F
In the formula:
X = iron content in wine samples in mg/L;
A = iron content calculated according to the regression equation in mg/L;
F = dilution factor, which is 10 in Lefeng's method.
6, precision
The absolute difference between two independent determinations obtained under repeatability conditions shall not exceed 10% of the arithmetic mean.
Copper content detection
The copper content was measured using an atomic absorption spectrophotometer equipped with a copper hollow cathode lamp with a detection wavelength of 324.07 nm. The remaining steps are tested with iron content.
In the above-mentioned atomic absorption spectrophotometric detection test, it is important to prepare a standard solution, dilute the sample solution, and clean the pure water quality, and the impurities therein may cause harm to the instruments and analysis results of the analysis and detection:
1. Particulate impurities in pure water can damage the injector and scatter light;
2. Organic matter can change the pH value, affecting the blank solution; it will also change the volatilization rate after complexing with iron and copper ions;
3. Ions can have a serious impact on absorbance, affecting the calculation of regression equations or standard curves;
4. Microbial metabolites increase pollutants such as ions and particles;
5. The gas easily forms bubbles, which affects the stability of the detection.
If unqualified pure water is used, not only the accuracy of the test results cannot be guaranteed, but also the atomic absorption spectrophotometer is easily damaged, shortening its life. At least the atomic absorption spectrophotometer should be in accordance with the national standard GB/T 6682-2008 "Analytical laboratory water specifications and test methods" (refer to the link http://rephile.com.cn/web/news-1686465.html) Water - Conductivity ≤ 1 μS/cm (25 ° C). It is preferable to use ultrapure water having a resistivity of 18.2 MΩ·cm.
In the wine testing laboratory, the analytical instruments such as gas chromatographs and high-performance liquid chromatographs are also required for water use, and need to meet the first-class pure water standard required by GB/T 6682-2008. Lefeng's new generation Genie G intelligent integrated ultra-pure water system can produce both EDI pure water and ultra-pure water. The EDI water produced by Genie G exceeds the secondary pure water standard required by GB/T 6682-2008; the ultrapure water exceeds the first grade pure water standard required by GB/T 6682-2008, and meets GB/T 33087-2016. High purity water standard for high purity water specifications and test methods for instrumental analysis. Genie G meets all the requirements of a wine testing laboratory. Lefeng also provides 3Q verification services in both Chinese and English to help the laboratory successfully pass the relevant certification in the US or EU. Genie G, using cutting-edge wireless communication tools, complete performance, powerful, free and flexible, can fully meet the needs of the high-end testing laboratory's overall water use, quality does not lose imported equipment, users can use it, you can completely "free water".
Reference Information:
1. Interpretation of Shanghai Lefeng's new laboratory pure water meter for you---Genie
2. GB/T 6682-2008 "Analytical laboratory water specifications and test methods"
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Keywords: pure water, wine, atomic absorption, OIV, Shanghai Lefeng, RephiLe, Genie water purifier, Super-Genie water purifier
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About Shanghai Lefeng Biotechnology Co., Ltd.
Shanghai Lefeng Bio is specialized in the research, development, design and manufacture of high-end water purification and laboratory separation and purification products, and is committed to providing cutting-edge, high value-added innovative products for life sciences and biotechnology. The Lefeng product line includes laboratory pure water systems, Millipore pure water compatible consumables and laboratory separation and purification filtration products. Established ten years ago, Lefeng has established its own brand RephiLe (Ruifeng), with more than 30 patents and multiple software copyrights. Products are sold to nearly 90 countries and regions around the world. For more information on RephiLe products, please visit: Le Feng official website 
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