GB/T 5009.48-2003 Analytical methods for hygienic standards of distilled spirits and blended spirits
Some standard content:
ICS.67.040
National Standard of the People's Republic of China
GB/T5009.48—2003
Replaces GB/T5009.48-1996
Method for analysis of hygienic standard of distilled wines and mixed winesPromulgated on August 11, 2003
Ministry of Health of the People's Republic of China
National Standardization Administration of China
Implementation on January 1, 2004
GB/T5009.48—2003
This standard replaces GB/T5009.48—1996 "Method for analysis of hygienic standard of distilled wines and mixed wines". Compared with GB/T5009.48-1996, this standard has been modified as follows: - The structure and content of the original standard have been modified in accordance with GB/T20001.4-2001 "Standard Preparation Rules Part 4: Chemical Analysis Methods";
- Gas chromatography is the first method for the determination of methanol and higher alcohols. This standard is proposed and managed by the Ministry of Health of the People's Republic of China. This standard is drafted by the Beijing Municipal Health and Epidemic Prevention Station, the Food Sanitation Supervision and Inspection Institute of the Ministry of Health, the Jinan Municipal Health and Epidemic Prevention Station, and the Guangdong Provincial Health and Epidemic Prevention Station.
This standard was first issued in 1985 and revised for the first time in 1996. This is the second revision. 402
1 Scope
Analysis methods for hygienic standards of distilled spirits and blended spirits GB/T5009.48—2003
This standard specifies the analysis methods for various hygienic indicators in liquor made from sugar- or starch-containing substances through saccharification, fermentation and distillation, and blended spirits made from fermented spirits or distilled spirits with edible auxiliary materials added as the base. This standard is applicable to the analysis of various hygienic indicators in distilled spirits and blended spirits. The detection limit of methanol is 0.02g/100mL.
The detection limit of fusel oil (calculated as isopentanol and isobutyl alcohol) is 0.03g/100mL. The detection limit of manganese is 0.50mg/L.
Distilled spirits refer to spirits with a volume fraction of more than 60 degrees. If the ethanol concentration is less than 60 degrees, the results of various determinations should be converted to the content at 60 degrees. After the blended liquor is distilled, the ethanol concentration is measured. When it is lower than 60 degrees, the various measurement results should also be converted into the content at 60 degrees. Normative reference documents
The clauses in the following documents become the clauses of this standard through reference in this standard. For all referenced documents with dates, all subsequent amendments (excluding errata) or revisions are not applicable to this standard. However, the parties who reach an agreement based on this standard are encouraged to study whether the latest versions of these documents can be used. For all referenced documents without dates, the latest versions are applicable to this standard. GB2757 Hygienic Standard for Distilled Liquor
GB/T5009.2 Determination of Relative Density in FoodsGB/T5009.11--2003 Determination of Total Arsenic in FoodsGB/T5009.12 Determination of Lead in Foods
GB/T5009.35 Determination of Colorants in FoodsGB/T5009.36--2003 Analytical Methods for Food Hygiene StandardsGB/T5009.90 Determination of Iron, Magnesium and Manganese in Foods3 Sensory Inspection
3.1 Take 30mL of the sample and pour it into a 50mL clean, dry, colorless glass beaker. Observe its color. It should be transparent without precipitation or impurities. 3.2 Taste it. It should have the unique aroma and flavor of this type of wine. It should not have moldy, sour or foreign smell. It should comply with the provisions of GB2757. 4 Physical and chemical tests
4.1 Ethanol concentration (density meter method)
4.1.1 Principle
Same as the principle of GB/T5009.2.
4.1.2 Instrument
Alcohol density meter.
4.1.3 Analysis steps
Put 100mL of sample in a 250mL or 500mL all-glass distiller, add 50mL of water, and then add a few glass beads, steam the filling, and collect 100mL of distillate in a 100mL volumetric flask. Pour the distilled sample into a measuring cylinder, slowly sink the cleaned and dried alcohol meter into the measuring cylinder, and gently press it down a little after it stops. After it rises and stops, observe the scale at the intersection with the liquid surface from a horizontal position, which is the ethanol concentration. At the same time, measure the temperature. According to the measured temperature and concentration, refer to Table 1 and convert it into the ethanol concentration (% volume fraction) at a temperature of 20℃. 403
GB/T5009.48-2003
4.2 Methanol and higher alcohols (gas chromatography) 4.2.1 Principle
Use chemical ionization of different alcohols in hydrogen flame for detection, and quantify according to peak height and standard comparison. Detection limit: n-propanol, n-butanol 0.2ng, isopentanol, n-pentanol 0.15ng; sec-butanol, isobutanol 0.22ng. 4.2.2 Reagents
4.2.2.1 Carrier: GDX-102 (60-80 mesh), for gas chromatography. 4.2.2.2 Methanol: chromatographically pure.
n-propanol: chromatographically pure.
sec-butanol: chromatographically pure.
isobutanol: chromatographically pure.
n-butanol: chromatographically pure.
isopentanol: chromatographically pure.
Ethyl acetate: chromatographically pure.
Methanol-free and fusel oil-free ethanol, operate according to 4.4.2.2, and measure its alcohol content. Take 0.5uL for injection and no impurity peaks appear. 4.2.2.9
4.2.2.10 Standard solution: Accurately weigh 600mg each of methanol, n-propanol, sec-butanol, isobutanol, n-butanol, isopentanol and 800mg of ethyl acetate, wash into a 100mL volumetric flask with a small amount of water, dilute to the mark with water, and store in a refrigerator. 4.2.2.11 Standard working solution: Pipette 10.0mL of standard solution into a 100mL volumetric flask, add a certain amount of ethanol treated in 4.2.2.9 to make up the volume, control the ethanol content at 60%, and dilute to the mark with water. This solution is stored in a refrigerator for future use (or prepared according to the sensitivity of the instrument). 4.2.3 Instruments
4.2.3.1 Gas chromatograph: with hydrogen flame ionization detector. 4.2.3.2 Micro-injection syringe: 1μL, 50μL. 4.2.4 Analysis steps
4.2.4.1 Chromatographic reference conditions
4.2.4.1.1 Chromatographic column, 2m long, 4mm inner diameter, glass column or stainless steel column. 4.2.4.1.2
Stationary phase: GDX-102, 60 mesh ~ 80 days. 4.2.4.1.3 Vaporization chamber temperature: 190℃. Detector temperature: 190℃.
4.2. 4. 1. 4
4.2.4.1.5
4. 2. 4. 1. 6
4.2.4.1.7
Column temperature: 170℃.
Carrier gas (Nz) flow rate: 40mL/min.
Hydrogen (H,) flow rate: 40mL/min.
3Air flow rate: 450mL/min.
4.2.4.1.8
4.2.4.1.9Injection volume: 0.5μL.
4.2.5Qualitative analysis
Qualitative analysis is performed based on the retention time of each component. Pipette 0.50uL of the standard working solution and the sample solution respectively, and measure the retention time respectively. The sample is qualitatively analyzed by comparing it with the standard elution time.
4.2.6 Quantification
Inject 0.5μL of standard solution to obtain a chromatogram, and measure the peak height of each component. Inject 0.50μL of sample to obtain a chromatogram, and measure the peak height, and compare and calculate with the standard peak height. 4.2.7 Calculation of results
The total amount of isobutyl alcohol and isopentanol in fusel oil is calculated as shown in formula (1). X
h,XA×V
h.xV.x1000×100
（1）
Wherein:
X--the content of a component in the sample, in grams per hundred milliliters (g/100mL); A--the content of a component in the injection standard, in milligrams per milliliter (mg/mL); h--the peak height of a component in the sample, in millimeters (mm); hz--the peak height of a component in the standard, in millimeters (mm); V?--the injection volume of the sample solution, in microliters (μL); V,--the injection volume of the standard solution, in microliters (uL). The calculation result shall retain two significant figures.
GB/T5009.48-2003
4.2.8 Precision
The absolute difference between two independent determination results obtained under repeatability conditions shall not exceed 20% of the arithmetic mean. 4.3 Methanol
4.3.1 Principle
After methanol is oxidized to formaldehyde, it reacts with fuchsin sulfurous acid to generate a blue-purple compound, which is quantitatively compared with the standard series. 4.3.2 Reagents
4.3.2.1 Potassium permanganate-phosphoric acid solution: Weigh 3g potassium permanganate, add it to a mixture of 15mL phosphoric acid (85%) and 70mL water, and add water to 100mL after dissolving. Store in a brown bottle to prevent the oxidation power from decreasing. The storage time should not be too long. 4.3.2.2 Oxalic acid-sulfuric acid solution: Weigh 5g anhydrous oxalic acid (H,C0) or 7g oxalic acid containing 2 molecules of crystal water (HzCzO,,2H20), and dissolve it in sulfuric acid (1+1) to 100mL. 4.3.2.3 Fuchsin-sulfite solution: Weigh 0.1g of basic fuchsin and grind it into powder. Add 60mL of 80℃ water in portions. Grind it while adding water to dissolve it. Use a dropper to absorb the upper layer of solution and filter it into a 100mL volumetric flask. After cooling, add 10mL of sodium sulfite solution (100g/L) and 1mL of hydrochloric acid. Add water to the mark, mix thoroughly, and leave overnight. If the solution has color, add a small amount of activated carbon, stir, filter, store in a brown bottle, and store in a dark place. If the solution is red, discard it and prepare it again. 4.3.2.4 Methanol standard solution: Weigh 1.000g of methanol, place it into a 100mL volumetric flask, and dilute it to the mark with water. Each milliliter of this solution is equivalent to 10.0mg of methanol. Store it at low temperature. 4.3.2.5 Methanol standard working solution: Take 10.0mL of methanol standard solution, place it into a 100mL volumetric flask, and dilute it to the mark with water. Take 25.0mL of the diluted solution and place it in a 50mL volumetric flask. Add water to the mark. Each mL of the solution is equivalent to 0.50mg of methanol. 4.3.2.6 Ethanol solution without methanol: Take 0.3mL and check according to the operating method. No color should be developed. If color is developed, it needs to be treated. Take 300mL of ethanol (95%), add a little potassium permanganate, distill, and collect the distillate. Add silver nitrate solution (take 1g of silver nitrate and dissolve it in a small amount of water) and sodium hydroxide solution (take 1.5g of sodium hydroxide and dissolve it in a small amount of water) to the distillate, shake well, take the supernatant and distill, discard the first 50mL of the effluent, collect about 200mL of the middle effluent, measure its concentration with an alcohol hydrometer, and then add water to make methanol-free ethanol (volume fraction is 60%)
4.3.2.7 Sodium sulfite solution (100g/L). 4.3.3 Instrument
Spectrophotometer.
4.3.4 Analysis steps
According to the ethanol concentration in the sample, take appropriate samples (ethanol concentration: 30%, take 1.0mL; 40%, take 0.80mL; 50%, take 0.60mL; 60%, take 0.50mL), and place them in a 25mL stoppered colorimetric tube. Colored or turbid distilled spirits and blended spirits shall be treated according to the method in 4.1.3 and then sampled according to the above sampling volume. Pipette 0, 0.100.20, 0.40, 0.60.0.80, 1.00mL of methanol standard working solution (equivalent to 0, 0.05.0.10, 0.20, 0.30, 0.40, 0.50mg of methanol) and place them in 25mL stoppered colorimetric tubes respectively, and add 0.5mL of methanol-free ethanol (volume fraction is 60%). Add water to each of the sample tube and the standard tube to make it 5 ml. Then add 2 mL of potassium permanganate-phosphoric acid solution to each tube, mix well, and place for 10 min. Then add 2 mL of oxalic acid-sulfuric acid solution to each tube, mix to fade, and then add 5 mL of fuchsin-sulfurous acid solution to each tube, mix well, and place at a temperature above 20°C for 0.5 h. Use a 2 cm colorimetric cup and a zero tube to adjust the zero point. Measure the absorbance at a wavelength of 590 nm, draw a standard curve for comparison, or visually compare with the standard series. 405
GB/T5009.48—2003
4.3.5 Calculation of results
The content of methanol in the sample is calculated according to formula (2). X=Vx1000×100
Wherein:
X--the content of methanol in the sample, in grams per hundred milliliters (g/100mL);--the mass of methanol in the measured sample, in milligrams (mg); m
V--the volume of the sample, in milliliters (mL). The calculation result shall retain two significant figures.
4.3.6 Precision
(2)
The absolute difference between two independent determination results obtained under repeatability conditions shall not exceed the arithmetic mean: ≤15% for content ≥0.10g/100mL and ≤20% for content <0.10g/100mL. 4.4 Fusel oil
4.4.1 Principle
Fusel oil has a complex composition, including n-ethanol, n- and isoamyl alcohol, n- and isobutanol, propanol, etc. The determination standard of this method is represented by isoamyl alcohol and isobutanol. Isoamyl alcohol and isobutanol generate pentene and butene under the action of sulfuric acid, and then react with p-dimethylaminobenzaldehyde to produce orange-yellow color, and compare with the standard series for quantitative determination.
4.4.2 Reagents
4.4.2.1 p-dimethylaminobenzaldehyde-sulfuric acid solution (5g/L). Take 0.5g of p-dimethylaminobenzaldehyde and add sulfuric acid to dissolve to 100mL. 4.4.2.2 Ethanol without fusel oil: Take 0.1mL and check according to the analysis steps. If it does not show color, it needs to be treated. Take the intermediate distillate of 4.3.2.6, add 0.25g of m-phenylenediamine hydrochloride, heat and reflux for 2h, use a fractionating column to control the boiling point for distillation, and collect 100mL of the intermediate distillate. Take another 0.1mL and measure according to the analysis steps. If it does not show color, it can be used. 4.4.2.3 Fusel oil standard solution: Accurately weigh 0.080g isoamyl alcohol and 0.020g isobutyl alcohol into a 100mL volumetric flask, add 50mL of ethanol without fusel oil, and dilute to the mark with water. Each mL of this solution is equivalent to 1mg of fusel oil, and store at low temperature. 4.4.2.4 Fusel oil standard working solution: Pipette 5.0mL of fusel oil standard solution into a 50mL volumetric flask, and dilute to the mark with water. Each mL of this solution is equivalent to 0.10mg of fusel oil. 4.4.3 Instrument
Spectrophotometer.
4.4.4 Analysis steps
Pipette 1.0mL of sample into a 10mL volumetric flask, add water to the mark, mix well, and then pipette 0.30mL and place in a 10mL colorimetric tube. Distilled liquor and blended liquor containing sugar coloring, precipitation, and mixing should be operated according to 4.1.3, and the distillate should be taken as the sample. Take 0.0.10, 0.20, 0.30, 0.40, 0.50mL of standard solution of fusel oil (equivalent to 0, 0.010, 0.020, 0.030, 0.040, 0.050mg of fusel oil) and place it in a 10mL colorimetric tube. Add water to the sample tube and standard tube accurately to 1mL, shake well, put in cold water to cool, add 2mL of p-dimethylaminobenzaldehyde-sulfuric acid solution (5g/L) along the tube wall, let it sink to the bottom of the tube, then shake all the tubes at the same time, put them in a boiling water bath to heat for 15min, take them out, immediately put them in an ice bath to cool, and immediately add 2mL of water to each, mix, and cool. After 10min, use a 1cm colorimetric cup with a zero tube to adjust the zero point, measure the absorbance at a wavelength of 520nm, draw a standard curve for comparison, or compare with the standard color column visually for quantification. 4.4.5 Calculation of results
The content of fusel oil in the sample is calculated according to formula (3). Where:
X V.×v/10 x1000 ×100
X-the content of fusel oil in the sample, g/100mL; m
-the mass of fusel oil in the sample diluent, mg; V2-the volume of the sample, in milliliters (mL); 406
(3)
V,-the volume of the sample dilution for determination, in milliliters (mL). The calculation result shall retain two significant figures.
4.4.6 Precision
GB/T5009.48—2003
The absolute difference between two independent determination results obtained under repeatability conditions shall not exceed 10% of the arithmetic mean. 4.5 Lead
Operate according to GB/T5009.12.
4.6.1 Atomic absorption spectrometry
Operate in accordance with GB/T5009.90.
4.6.2 Colorimetry
4.6.2.1 Principle
After digestion, the sample is oxidized by potassium periodate to heptavalent manganese under acidic conditions and the color is purplish red. The sample is then compared with the standard for quantitative determination. 4.6.2.2 Reagents
4.6.2.2.1 Sulfuric acid.
Phosphoric acid.
4.6.2.2.2
4.6.2.2.3
3 Potassium periodate.
Nitric acid.
4.6.2.2, 4
Manganese standard solution: accurately weigh 0.2746g of manganese sulfate burned to a constant weight at 400℃~700℃, or accurately weigh 4.6.2.2.5
0.3073g of manganese sulfate containing one molecule of water (MnSO.·HzO), or 0.4055g of manganese sulfate containing four molecules of water (MnSO.·4H.O), dissolve in water and transfer to a 100mL volumetric flask, add 3 drops of sulfuric acid, and dilute to scale with water. This solution is equivalent to 1.0mg manganese per milliliter.
4.6.2.2.6 Manganese standard solution: Take 1.0mL of manganese standard solution and place it in a 100mL volumetric flask, dilute to scale with water, and then take 10.0mL of this solution and dilute to 50.0mL with water. This solution is equivalent to 2.0μg manganese per milliliter. Prepare before use. 4.6.2.3 Instruments
Spectrophotometer.
4.6.2.4 Analysis steps
4.6.2.4.1 Sample digestion: Operate according to 5.1.14 of GB/T5009.11-2003. 4.6.2.4.2 Determination: Pipette 10.0mL of sample digestion solution (equivalent to 4mL of original sample) into a 100mL conical flask, add water to a total volume of 22mL, and mix well (the sample digestion solution contains 2mL of sulfuric acid. If it is less than 2mL, add to 2mL). Pipette 0, 1.0, 2.0, 3.0, 4.0, 5.0mL of manganese standard working solution (equivalent to 0, 2.0, 4.06.0, 8.0, 10.0μg manganese), respectively, into 100mL conical flasks, add water to a total volume of 20mL, then add 2mL of sulfuric acid and mix. Add 1.5mL of phosphoric acid and 0.3g of potassium periodate to the sample and standard solution conical flasks, respectively, and mix well. Boil on low heat for 5 minutes, then transfer to a 25mL colorimetric tube, wash the conical flask with a small amount of water, transfer the washing liquid to the colorimetric tube, add water to the scale, mix well, use a 3cm colorimetric cup, adjust the zero point with a standard zero tube, measure the absorbance at a wavelength of 530nm, draw a standard curve for comparison, or compare with the standard series by visual inspection for quantification.
4.6.2.5 Calculation of results
The manganese content in the sample is calculated according to formula (4). mx1000
X=VxV.N.X1 000
Wherein:
X-the content of manganese in the sample, in milligrams per liter (mg/L); m
the mass of manganese in the sample digestion solution, in micrograms (μg); (4)
GB/T5009.48—2003
V, the sample volume, in milliliters (mL); V——the total volume of the sample digestion solution, in milliliters (mL); V, the volume of the digestion solution used for determination, in milliliters (mL). The calculation result shall retain two significant figures.
4.6.2.6 Precision
The absolute difference between two independent determination results obtained under repeatability conditions shall not exceed 10% of the arithmetic mean. 4.7 Cyanide
4.7.1 Principle, reagents, instruments
Same as 4.4.2.1~4.4.2.3 of GB/T5009.36-2003. 4.7.2 Analysis steps
4.7.2.1 Pipette 1.0mL of sample into a 10mL stoppered colorimetric tube, add sodium hydroxide solution (2g/L) to 5mL, and leave for 10min. 4.7.2.2 If the wine sample is turbid or colored, take 25mL of sample into a 250mL all-glass distiller, add 5ml of sodium hydroxide solution (2g/L), alkaline hydrolysis for 10min, add saturated tartaric acid solution to make it acidic, perform steam distillation, absorb with 10ml of sodium hydroxide solution (2g/L), collect to 50mL, take 2mL of distillate into a 10mL stoppered colorimetric tube, add sodium hydroxide solution (2g/L) to 5mL. 4.7.2.3 Pipette 0.0.5, 1.0.1.5, and 2.0 mL of cyanide standard working solution (equivalent to 0, 0.5, 1.0, 1.5, and 2.0 g of hydrocyanic acid) into a 10 mL stoppered colorimetric tube, and add sodium hydroxide solution (2 g/L) to make up to 5 mL. 4.7.2.4 Add 2 drops of phenolic indicator to the sample and standard tube respectively, then add acetic acid (1+6) until the red color fades, then use sodium hydroxide solution (2g/L) to adjust to near red, then add 2mL phosphate buffer solution (if the room temperature is lower than 20℃, place in a 25℃~30℃ water bath for 10min), then add 0.2mL nitrogen amine T solution (10g/L), shake and place for 3min, add 2mL isonicotinic acid-pyrazolone solution, dilute to the scale with water, shake, place at 25℃~30℃ for 30min, take out and use a 1cm colorimetric cup to adjust the winter point with a zero tube, measure the absorbance at a wavelength of 638nm, and draw a standard curve for comparison. 4.7.3 Calculation of results
According to 4.7.2.1, the calculation formula is shown in formula (5). X=
Wherein:
m×1000
VX1000
The content of cyanide in the sample (calculated as hydrocyanic acid), in milligrams per liter (mg/L); m--the mass of hydrocyanic acid in the sample for determination, in micrograms (μg); V--the volume of the sample, in milliliters (mL). V
Perform the operation in 4.7.2.2, and the calculation formula is shown in formula (6). mx1000
X=V×2/50X1000
Wherein:
X--the content of cyanide in the sample (calculated as hydrocyanic acid), in milligrams per liter (mg/L); m--the mass of hydrocyanic acid in the distillate of the sample for determination, in micrograms (ug); V--the volume of the sample, in milliliters (mL). The calculation result shall retain two significant figures.
4.7.4 Precision
The absolute difference between two independent determination results obtained under repeatability conditions shall not exceed 10% of the arithmetic mean. 4.8 Colorants
Operate in accordance with GB/T5009.35.
（5）
（6）
Alcohol meter temperature concentration conversion table
When the temperature is +20℃, the ethanol concentration is expressed as a percentage of volume 64.0
GB/T5009.48-—2003
GB/T5009.48—2003
Table 1 (continued)
When the temperature is +20℃, the ethanol concentration is expressed as a percentage of volume 58.4
Table 1 (continued)
When the temperature is +20℃, the ethanol concentration is expressed as a percentage of volume 53.1
GB/T5009.48-2003
GB/T5009.48—2003
Table 1 (continued)
When the temperature is +20℃, the ethanol concentration is expressed as a percentage of volume 48.01 Principle, reagents, instruments
Same as 4.4.2.1~4.4.2.3 of GB/T5009.36-2003. 4.7.2 Analysis steps
4.7.2.1 Pipette 1.0mL of sample into a 10mL stoppered colorimetric tube, add sodium hydroxide solution (2g/L) to 5mL, and leave for 10min. 4.7.2.2 If the wine sample is turbid or colored, take 25mL of sample into a 250mL all-glass distiller, add 5ml of sodium hydroxide solution (2g/L), alkaline hydrolysis for 10min, add saturated tartaric acid solution to make it acidic, perform steam distillation, absorb with 10ml of sodium hydroxide solution (2g/L), collect to 50mL, take 2mL of distillate into a 10mL stoppered colorimetric tube, add sodium hydroxide solution (2g/L) to 5mL. 4.7.2.3 Pipette 0.0.5, 1.0.1.5, and 2.0 mL of cyanide standard working solution (equivalent to 0, 0.5, 1.0, 1.5, and 2.0 g of hydrocyanic acid) into a 10 mL stoppered colorimetric tube, and add sodium hydroxide solution (2 g/L) to make up to 5 mL. 4.7.2.4 Add 2 drops of phenolic indicator to the sample and standard tube respectively, then add acetic acid (1+6) until the red color fades, then use sodium hydroxide solution (2g/L) to adjust to near red, then add 2mL phosphate buffer solution (if the room temperature is lower than 20℃, place in a 25℃~30℃ water bath for 10min), then add 0.2mL nitrogen amine T solution (10g/L), shake and place for 3min, add 2mL isonicotinic acid-pyrazolone solution, dilute to the scale with water, shake, place at 25℃~30℃ for 30min, take out and use a 1cm colorimetric cup to adjust the winter point with a zero tube, measure the absorbance at a wavelength of 638nm, and draw a standard curve for comparison. 4.7.3 Calculation of results
According to 4.7.2.1, the calculation formula is shown in formula (5). X=
Wherein:
m×1000
VX1000
The content of cyanide in the sample (calculated as hydrocyanic acid), in milligrams per liter (mg/L); m--the mass of hydrocyanic acid in the sample for determination, in micrograms (μg); V--the volume of the sample, in milliliters (mL). V
Perform the operation in 4.7.2.2, and the calculation formula is shown in formula (6). mx1000
X=V×2/50X1000
Wherein:
X--the content of cyanide in the sample (calculated as hydrocyanic acid), in milligrams per liter (mg/L); m--the mass of hydrocyanic acid in the distillate of the sample for determination, in micrograms (ug); V--the volume of the sample, in milliliters (mL). The calculation result shall retain two significant figures.
4.7.4 Precision
The absolute difference between two independent determination results obtained under repeatability conditions shall not exceed 10% of the arithmetic mean. 4.8 Colorants
Operate in accordance with GB/T5009.35.
（5）
（6）
Alcohol meter temperature concentration conversion table
When the temperature is +20℃, the ethanol concentration is expressed as a percentage of volume 64.0
GB/T5009.48-—2003
GB/T5009.48—2003
Table 1 (continued)
When the temperature is +20℃, the ethanol concentration is expressed as a percentage of volume 58.4
Table 1 (continued)
When the temperature is +20℃, the ethanol concentration is expressed as a percentage of volume 53.1
GB/T5009.48-2003
GB/T5009.48—2003
Table 1 (continued)
When the temperature is +20℃, the ethanol concentration is expressed as a percentage of volume 48.01 Principle, reagents, instruments
Same as 4.4.2.1~4.4.2.3 of GB/T5009.36-2003. 4.7.2 Analysis steps
4.7.2.1 Pipette 1.0mL of sample into a 10mL stoppered colorimetric tube, add sodium hydroxide solution (2g/L) to 5mL, and leave for 10min. 4.7.2.2 If the wine sample is turbid or colored, take 25mL of sample into a 250mL all-glass distiller, add 5ml of sodium hydroxide solution (2g/L), alkaline hydrolysis for 10min, add saturated tartaric acid solution to make it acidic, perform steam distillation, absorb with 10ml of sodium hydroxide solution (2g/L), collect to 50mL, take 2mL of distillate into a 10mL stoppered colorimetric tube, add sodium hydroxide solution (2g/L) to 5mL. 4.7.2.3 Pipette 0.0.5, 1.0.1.5, and 2.0 mL of cyanide standard working solution (equivalent to 0, 0.5, 1.0, 1.5, and 2.0 g of hydrocyanic acid) into a 10 mL stoppered colorimetric tube, and add sodium hydroxide solution (2 g/L) to make up to 5 mL. 4.7.2.4 Add 2 drops of phenolic indicator to the sample and standard tube respectively, then add acetic acid (1+6) until the red color fades, then use sodium hydroxide solution (2g/L) to adjust to near red, then add 2mL phosphate buffer solution (if the room temperature is lower than 20℃, place in a 25℃~30℃ water bath for 10min), then add 0.2mL nitrogen amine T solution (10g/L), shake and place for 3min, add 2mL isonicotinic acid-pyrazolone solution, dilute to the scale with water, shake, place at 25℃~30℃ for 30min, take out and use a 1cm colorimetric cup to adjust the winter point with a zero tube, measure the absorbance at a wavelength of 638nm, and draw a standard curve for comparison. 4.7.3 Calculation of results
According to 4.7.2.1, the calculation formula is shown in formula (5). X=
Wherein:
m×1000
VX1000
The content of cyanide in the sample (calculated as hydrocyanic acid), in milligrams per liter (mg/L); m--the mass of hydrocyanic acid in the sample for determination, in micrograms (μg); V--the volume of the sample, in milliliters (mL). V
Perform the operation in 4.7.2.2, and the calculation formula is shown in formula (6). mx1000bzxz.net
X=V×2/50X1000
Wherein:
X--the content of cyanide in the sample (calculated as hydrocyanic acid), in milligrams per liter (mg/L); m--the mass of hydrocyanic acid in the distillate of the sample for determination, in micrograms (ug); V--the volume of the sample, in milliliters (mL). The calculation result shall retain two significant figures.
4.7.4 Precision
The absolute difference between two independent determination results obtained under repeatability conditions shall not exceed 10% of the arithmetic mean. 4.8 Colorants
Operate in accordance with GB/T5009.35.
（5）
（6）
Alcohol meter temperature concentration conversion table
When the temperature is +20℃, the ethanol concentration is expressed as a percentage of volume 64.0
GB/T5009.48-—2003
GB/T5009.48—2003
Table 1 (continued)
When the temperature is +20℃, the ethanol concentration is expressed as a percentage of volume 58.4
Table 1 (continued)
When the temperature is +20℃, the ethanol concentration is expressed as a percentage of volume 53.1
GB/T5009.48-2003
GB/T5009.48—2003
Table 1 (continued)
When the temperature is +20℃, the ethanol concentration is expressed as a percentage of volume 48.0
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