
GB/T 5009.30-2003 Determination of tert-butyl hydroxyanisole (BHA) and 2,6-di-tert-butyl-p-cresol (BHT) in foods
time:
2024-08-05 01:41:58
- GB/T 5009.30-2003
- in force
Standard ID:
GB/T 5009.30-2003
Standard Name:
Determination of tert-butyl hydroxyanisole (BHA) and 2,6-di-tert-butyl-p-cresol (BHT) in foods
Chinese Name:
食品中叔丁基羟基茴香醚(BHA)与2,6?二叔丁基对甲酚(BHT)的测定
Standard category:
National Standard (GB)
-
Date of Release:
2003-08-11 -
Date of Implementation:
2004-01-01
Standard ICS number:
Food Technology >> 67.040 Food ComprehensiveChina Standard Classification Number:
Medicine, Health, Labor Protection>>Health>>C53 Food Hygiene
alternative situation:
GB/T 5009.30-1996
Release date:
1985-05-16Review date:
2004-10-14Drafting Organization:
Beijing Municipal Health and Anti-epidemic StationFocal point Organization:
Ministry of Health of the People's Republic of ChinaProposing Organization:
Ministry of Health of the People's Republic of ChinaPublishing Department:
Ministry of Health of the People's Republic of China Standardization Administration of ChinaCompetent Authority:
Ministry of Health

Skip to download
Summary:
This standard specifies the determination method of BHA and BHT in foods such as cakes and vegetable oils. This standard is applicable to the determination of BHA and BHT in foods such as cakes and vegetable oils. The detection limit of this method: the detection amount of gas chromatography is 2.0μg, and the detection concentration is 4.0mg/g when the oil sampling amount is 0.50g. The detection amount of colorimetry is 10.0μg, and the detection concentration is 4.0mg/kg when the oil sampling amount is 0.25g. The optimal linear range of gas chromatography: 0.0μg~100.0μg. GB/T 5009.30-2003 Determination of tert-butylhydroxyanisole (BHA) and 2,6?-di-tert-butyl-p-cresol (BHT) in food GB/T5009.30-2003 Standard download decompression password: www.bzxz.net

Some standard content:
National Standard of the People's Republic of China
GB/T5009.30——2003
GB/T00980—1906
Determination of butylated hydroxyanisole (BHA) and 2,6-di-tert-butylated hydroxycresol (BHT) in foods2003-08-11Promulgated
Ministry of Health of the People's Republic of China
China National Standardization Administration
2004-01-01Implementation
GB/T 5009.30—2003
This standard replaces GB/T5CC9.80—1SS6 Determination of Butyl Hydroxypropyl Hazardous Acid (BHA) and 2,6-Dihydroxybutyl Hydroxypropyl Hazardous Acid (BHI) in Food
Compared with GB0—6, this standard has the following changes:
The Chinese name of the standard has been modified, and the Chinese name has been changed to Determination of Butyl Hydroxypropyl Hazardous Acid (HHA) and 2,6-Dihydroxybutyl Hydroxypropyl Hazardous Acid (BI1T) in Food
The structure of the original standard has been modified according to Part 4 of the Comprehensive Rules of GB3/20001.4—2000: Chemical Analysis Method
This standard was proposed and supervised by the Ministry of Health of the People's Republic of China. This standard was sponsored by Jiangsu Provincial Health and Safety Station. This standard is only issued to the Ministry of Health and the inspection institutes of food safety supervision, Wuhan Municipal Health and Epidemic Prevention Station and Youdan Health and Epidemic Prevention Station. This standard is only issued by Shanghai Municipal Health and Epidemic Prevention Station. This standard was issued in 1996, the first time it was subscribed, and this is the second time it was subscribed. 242
1 Scope
Determination of tert-butyl hydroxy ether (BHA) and 2,6-ditert-butyl para-cresol (BHT) in foods This standard specifies the determination method of tert-butyl hydroxy ether (BHA) and 2,6-ditert-butyl para-cresol (BHT) in foods such as pastry and vegetable oils. This standard specifies the determination method of tert-butyl hydroxy ether (BHA) and 2,6-ditert-butyl para-cresol (BHT) in foods such as pastry and vegetable oils. This standard specifies the determination method of tert-butyl hydroxy ether (BHA) and 2,6-ditert-butyl para-cresol (BHT) in foods such as pastry and vegetable oils. This standard specifies the determination method of tert-butyl hydroxy ether (BHA) and 2,6-ditert-butyl para-cresol (BHT) in foods such as pastry and vegetable oils. GB/T 5009.3D—2003
This standard has a detection limit of 2.1ug for gas chromatography-mass spectrometry and a detection accuracy of 4.0mg/kg when the sample fat is 0.50g. The detection amount of colorimetric method is 10%, and the detection concentration is 4.nmR/k when the oil sampling amount is 1. The linear range of gas chromatography: 0.0 #g--100.0 μg
Method 1 Gas chromatography
2 Principle
BHA and 2,6-dihydroxy-p-cresol (BHT) in the sample are extracted with benzophenone, and TH4 and BHT are purified by chromatography column. After concentration, the gas chromatographic analysis is performed and then the chromatographic peak is detected by a paraffin chiral detector. The quantification is performed by comparing the peak quotient of the test sample with the peak quotient of the standard.
3 Reagents
3.1 BHA: boiling temperature 39℃--60℃:
3.2 Dimethoxymethane, analytical grade,
3 .3 Magnetic acid, analytically pure
3.4 Anhydrous nitric acid, standard purity.
3.5 Silica gel G, activated at 120 °C for 4h, placed in a desiccator for 4h: 3.6 Accumulated F: 60--0 days, dried at 120 °C for 4h, placed in a desiccator for use. 3.7 TLA, FIT mixed standard solution: make sure the concentration of each solution is S9. Take 0.1 HITA, BTIT each, mix and adjust to 100 mL with a magnetic melt, the total concentration is 0.01-0.00 mg BHA and BHT per liter, store in an egg box. 3.8 Use of BIIA, BIIT mixed standard: pipette 4.0 mL of standard stock solution into a 100 mL volumetric bottle and add 1 mL of carbon disulfide to a 100 mL Tril volumetric bottle. The sieves contain 0.140 mg HHA and HHT per liter, respectively. Store in a refrigerator. 4 Apparatus 4.1 Gas phase negative electrode with FIL detector 4.2 Analyzer: volume 200 mL. 4.3 Analyzer 4.4 Column: 1 cm x 30 cm glass column with active layer 4.5 Gas chromatograph: 1.5 mV diameter Amml energy glass mill filled with 10% QF-1 (GasChromQ(80-100) 5. Sample preparation 5.1 Sample preparation Weigh the sample with more fat content and the sample with less fat content. Take one-sixth or one-sixth of the sample diagonally after burning or take the sample with good surface quality according to the sample conditions, grind in a glass mortar, mix well and put in a bottle and store in a refrigerator. 243 GB/T5009.30—20C3 5. 2 Kidney extraction
5.2.1 Test pieces containing high oil content (such as pancakes, etc.): weigh 50 ml of puree, put into 20 ml of dry bottle (the time required is 30 minutes), put into the stomach, filter with filter paper, reduce the pressure and return to the original state until the residue is removed for use: 5.2.2 Test pieces containing medium oil content (such as cake strips, etc.): weigh 10 ml of puree, mix well, add 10 ml of puree to 500 ml of water, add 1 ml of 20 ml of water (the time required is 30 minutes), store overnight, filter with filter paper, reduce the pressure and return to the original state until the residue is removed for use: 5.2.2 Test pieces containing medium oil content (such as cake strips, etc.): weigh 10 ml of puree, mix well, add 10 ml of puree to 500 ml of water, add 1 ml of 20 ml of water (the time required is 30 minutes), store overnight, filter with filter paper, reduce the pressure and return to the original state until the residue is removed for use. ||5.2.3 Samples containing less hydroxyl radicals (including cakes, etc.), weigh 28g~953g of coupling agent, put them into a 500l cold conical flask, add appropriate amount of sodium ion, place them overnight, filter them with fast filter paper, and shorten the recovery belt for use. 6 Analysis Steps
6.1 Preparation of Samples
6.1.1 Preparation of Chromatographic Columns, add a small amount of chromatographic column to the bottom of the column, add the least amount of anhydrous sodium ion, add 1% sodium ion to the bond gel-florin (600g), and assemble them by non-wetting method, and add a small amount of anhydrous sodium ion to the injection. 6.1.2 Sample preparation: weigh the fat (23g/ml) prepared in 5.2 and transfer it to the new layer of 6.1.1. You can use 100mL of dichloromethane to wash it five times, and then inject it into the well under reduced pressure. Use dihydrogen ether to make it 2.0mL. This alcohol solution is the solution to be identified.
6.1.3 Sample preparation: Take 2.00mL of the mixed sample and put it into 0mL ethanol. Add 30mL of dihydrogen ether solution and transfer it to the chromatography column of 5.1.1. The alcohol solution is 10mL of petroleum ether. Wash several times in a chromatographic filter and transfer to a chromatographic syringe. Add 1001% dioxygen five times, combine the precipitates, concentrate under reduced pressure, and make up to 2.0 ml with disulfide solution (the solution can be used as the test solution, 6.2 Determination of the concentration of the sample to be tested). 3. Prepare a gas chromatograph: Use a standard liquid test solution to prepare a color spectrum, and collect the peak height or area of each component respectively. The concentration of the sample to be tested depends on the test content). Prepare a graph: collect the peak height or area, and calculate the content by comparing it with the standard peak height or area. 6.3 Calculate the results to obtain the test rate RFIA (composition) or according to the composition.Energy, unit is g (): Mass of oily food, unit is g): Calculation results shall retain one significant figure.
7 Precision bottom
GB/T5009.30—2003
The absolute value of two independent determination results obtained under repeated conditions shall not exceed about 15% of the calculated half mean. 8 Others
8.113JIA, BHT gas chromatograph see Figure 1.
8.2 Reference conditions for gas phase spectrometry
Chromatograph: glass filler with a length of 1.5m and an inner diameter of 3mm, detector: CaaChrom (3uDa~10uDa) with a tooth fraction of 12%, QF: FE),
temperature chamber ℃, injection ℃, flow rate of carrier gas to the plate 14: nitrogen 7ral./min, oxygen 5mlL/min, air 00m/min. Method II Thin layer chromatograph
9 Principle
Use methanol to extract antioxidants in oily foods and qualitatively analyze them by thin layer chromatography. According to the ratio of its minimum elution amount after chromatography on the thin layer plate with the minimum detection amount after standard, HHI, HHA and PC in high-quality foods can be qualitatively detected. 10 Reagents
10.1 Alcohol
10.2 Right oil ether (3n).
G6/T 5009.30—2003
10. 3 Isoalkane.
10.4 Propane,
15.5 Ethylene,
10,6 Normal alkane.
Monohexane. bZxz.net
10. 8 For post-forming layer.
Zincamide powder 2WI days.
10.10 Preparation of the standard solution of BH, BHA, and PG filtration: accurately weigh BHT and BHA1, respectively. The purity is more than 99.9%. Discard 0mR and transfer two samples into two 1-well tubes. Use acetone to dilute to the scale. This solution contains 0.20mgIT, 0.06nmgBIIA, 0.0GGagFG per liter. 10.12 Color developer: 7.0% static solution of 2.5-dichloro-1,3-dihydro-1-imide (2g/L). 11 Receiver
11. 1 Vacuum distillation device,
11.2 Length of the tube concentration bottle:
11.3 Layer folding Kun:
) 24 nx6 r:x4 er:
h)20rmx13rmRrm.
11.4 Glass collection: 5cmx20.13crx23
11.5 Micro syringe, 0.0]..
12 Analysis steps
-2.1.1 Vegetable oil (butter oil, soybean oil, soybean oil, peptide oil), weigh 5,U centrifuge 1, add 5,U centrifuge 10mlH, add 5mi1. Efficient 2ni. Huixin 3r/mi10mr/uin5ir absorb all the supernatant 2s. Apply, if more than one extraction, extract again every time, select to scale. 0m, electrostatic extract was placed in a concentrated stream, reduced pressure in 40% water to 0.5, prepared by mixing 2.1.2 ml of H2O, take 5.9 ml of H2O and put it in a conical flask with a pressure gauge, add 23.0 ml of methanol and condense it in water for 7s. After the condensate is completely dissolved, place the conical flask together with the condensate in a water bath and shake for 30 min. Then put it in a water bath and cool it down for 30 min (water bath, make the oil layer in the container, and place the conical flask in a cold chain tube in the water bath). Pass the oil and other extracts through a paper filter into a receiving bottle, then add the condensate to the source at 25 pm, repeat the extraction, and add the second alcohol extract, spray the dose into the stomach, wait for the rate to rise, and absorb 1 ml of alcohol at 30 pm.
Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.
GB/T5009.30——2003
GB/T00980—1906
Determination of butylated hydroxyanisole (BHA) and 2,6-di-tert-butylated hydroxycresol (BHT) in foods2003-08-11Promulgated
Ministry of Health of the People's Republic of China
China National Standardization Administration
2004-01-01Implementation
GB/T 5009.30—2003
This standard replaces GB/T5CC9.80—1SS6 Determination of Butyl Hydroxypropyl Hazardous Acid (BHA) and 2,6-Dihydroxybutyl Hydroxypropyl Hazardous Acid (BHI) in Food
Compared with GB0—6, this standard has the following changes:
The Chinese name of the standard has been modified, and the Chinese name has been changed to Determination of Butyl Hydroxypropyl Hazardous Acid (HHA) and 2,6-Dihydroxybutyl Hydroxypropyl Hazardous Acid (BI1T) in Food
The structure of the original standard has been modified according to Part 4 of the Comprehensive Rules of GB3/20001.4—2000: Chemical Analysis Method
This standard was proposed and supervised by the Ministry of Health of the People's Republic of China. This standard was sponsored by Jiangsu Provincial Health and Safety Station. This standard is only issued to the Ministry of Health and the inspection institutes of food safety supervision, Wuhan Municipal Health and Epidemic Prevention Station and Youdan Health and Epidemic Prevention Station. This standard is only issued by Shanghai Municipal Health and Epidemic Prevention Station. This standard was issued in 1996, the first time it was subscribed, and this is the second time it was subscribed. 242
1 Scope
Determination of tert-butyl hydroxy ether (BHA) and 2,6-ditert-butyl para-cresol (BHT) in foods This standard specifies the determination method of tert-butyl hydroxy ether (BHA) and 2,6-ditert-butyl para-cresol (BHT) in foods such as pastry and vegetable oils. This standard specifies the determination method of tert-butyl hydroxy ether (BHA) and 2,6-ditert-butyl para-cresol (BHT) in foods such as pastry and vegetable oils. This standard specifies the determination method of tert-butyl hydroxy ether (BHA) and 2,6-ditert-butyl para-cresol (BHT) in foods such as pastry and vegetable oils. This standard specifies the determination method of tert-butyl hydroxy ether (BHA) and 2,6-ditert-butyl para-cresol (BHT) in foods such as pastry and vegetable oils. GB/T 5009.3D—2003
This standard has a detection limit of 2.1ug for gas chromatography-mass spectrometry and a detection accuracy of 4.0mg/kg when the sample fat is 0.50g. The detection amount of colorimetric method is 10%, and the detection concentration is 4.nmR/k when the oil sampling amount is 1. The linear range of gas chromatography: 0.0 #g--100.0 μg
Method 1 Gas chromatography
2 Principle
BHA and 2,6-dihydroxy-p-cresol (BHT) in the sample are extracted with benzophenone, and TH4 and BHT are purified by chromatography column. After concentration, the gas chromatographic analysis is performed and then the chromatographic peak is detected by a paraffin chiral detector. The quantification is performed by comparing the peak quotient of the test sample with the peak quotient of the standard.
3 Reagents
3.1 BHA: boiling temperature 39℃--60℃:
3.2 Dimethoxymethane, analytical grade,
3 .3 Magnetic acid, analytically pure
3.4 Anhydrous nitric acid, standard purity.
3.5 Silica gel G, activated at 120 °C for 4h, placed in a desiccator for 4h: 3.6 Accumulated F: 60--0 days, dried at 120 °C for 4h, placed in a desiccator for use. 3.7 TLA, FIT mixed standard solution: make sure the concentration of each solution is S9. Take 0.1 HITA, BTIT each, mix and adjust to 100 mL with a magnetic melt, the total concentration is 0.01-0.00 mg BHA and BHT per liter, store in an egg box. 3.8 Use of BIIA, BIIT mixed standard: pipette 4.0 mL of standard stock solution into a 100 mL volumetric bottle and add 1 mL of carbon disulfide to a 100 mL Tril volumetric bottle. The sieves contain 0.140 mg HHA and HHT per liter, respectively. Store in a refrigerator. 4 Apparatus 4.1 Gas phase negative electrode with FIL detector 4.2 Analyzer: volume 200 mL. 4.3 Analyzer 4.4 Column: 1 cm x 30 cm glass column with active layer 4.5 Gas chromatograph: 1.5 mV diameter Amml energy glass mill filled with 10% QF-1 (GasChromQ(80-100) 5. Sample preparation 5.1 Sample preparation Weigh the sample with more fat content and the sample with less fat content. Take one-sixth or one-sixth of the sample diagonally after burning or take the sample with good surface quality according to the sample conditions, grind in a glass mortar, mix well and put in a bottle and store in a refrigerator. 243 GB/T5009.30—20C3 5. 2 Kidney extraction
5.2.1 Test pieces containing high oil content (such as pancakes, etc.): weigh 50 ml of puree, put into 20 ml of dry bottle (the time required is 30 minutes), put into the stomach, filter with filter paper, reduce the pressure and return to the original state until the residue is removed for use: 5.2.2 Test pieces containing medium oil content (such as cake strips, etc.): weigh 10 ml of puree, mix well, add 10 ml of puree to 500 ml of water, add 1 ml of 20 ml of water (the time required is 30 minutes), store overnight, filter with filter paper, reduce the pressure and return to the original state until the residue is removed for use: 5.2.2 Test pieces containing medium oil content (such as cake strips, etc.): weigh 10 ml of puree, mix well, add 10 ml of puree to 500 ml of water, add 1 ml of 20 ml of water (the time required is 30 minutes), store overnight, filter with filter paper, reduce the pressure and return to the original state until the residue is removed for use. ||5.2.3 Samples containing less hydroxyl radicals (including cakes, etc.), weigh 28g~953g of coupling agent, put them into a 500l cold conical flask, add appropriate amount of sodium ion, place them overnight, filter them with fast filter paper, and shorten the recovery belt for use. 6 Analysis Steps
6.1 Preparation of Samples
6.1.1 Preparation of Chromatographic Columns, add a small amount of chromatographic column to the bottom of the column, add the least amount of anhydrous sodium ion, add 1% sodium ion to the bond gel-florin (600g), and assemble them by non-wetting method, and add a small amount of anhydrous sodium ion to the injection. 6.1.2 Sample preparation: weigh the fat (23g/ml) prepared in 5.2 and transfer it to the new layer of 6.1.1. You can use 100mL of dichloromethane to wash it five times, and then inject it into the well under reduced pressure. Use dihydrogen ether to make it 2.0mL. This alcohol solution is the solution to be identified.
6.1.3 Sample preparation: Take 2.00mL of the mixed sample and put it into 0mL ethanol. Add 30mL of dihydrogen ether solution and transfer it to the chromatography column of 5.1.1. The alcohol solution is 10mL of petroleum ether. Wash several times in a chromatographic filter and transfer to a chromatographic syringe. Add 1001% dioxygen five times, combine the precipitates, concentrate under reduced pressure, and make up to 2.0 ml with disulfide solution (the solution can be used as the test solution, 6.2 Determination of the concentration of the sample to be tested). 3. Prepare a gas chromatograph: Use a standard liquid test solution to prepare a color spectrum, and collect the peak height or area of each component respectively. The concentration of the sample to be tested depends on the test content). Prepare a graph: collect the peak height or area, and calculate the content by comparing it with the standard peak height or area. 6.3 Calculate the results to obtain the test rate RFIA (composition) or according to the composition.Energy, unit is g (): Mass of oily food, unit is g): Calculation results shall retain one significant figure.
7 Precision bottom
GB/T5009.30—2003
The absolute value of two independent determination results obtained under repeated conditions shall not exceed about 15% of the calculated half mean. 8 Others
8.113JIA, BHT gas chromatograph see Figure 1.
8.2 Reference conditions for gas phase spectrometry
Chromatograph: glass filler with a length of 1.5m and an inner diameter of 3mm, detector: CaaChrom (3uDa~10uDa) with a tooth fraction of 12%, QF: FE),
temperature chamber ℃, injection ℃, flow rate of carrier gas to the plate 14: nitrogen 7ral./min, oxygen 5mlL/min, air 00m/min. Method II Thin layer chromatograph
9 Principle
Use methanol to extract antioxidants in oily foods and qualitatively analyze them by thin layer chromatography. According to the ratio of its minimum elution amount after chromatography on the thin layer plate with the minimum detection amount after standard, HHI, HHA and PC in high-quality foods can be qualitatively detected. 10 Reagents
10.1 Alcohol
10.2 Right oil ether (3n).
G6/T 5009.30—2003
10. 3 Isoalkane.
10.4 Propane,
15.5 Ethylene,
10,6 Normal alkane.
Monohexane. bZxz.net
10. 8 For post-forming layer.
Zincamide powder 2WI days.
10.10 Preparation of the standard solution of BH, BHA, and PG filtration: accurately weigh BHT and BHA1, respectively. The purity is more than 99.9%. Discard 0mR and transfer two samples into two 1-well tubes. Use acetone to dilute to the scale. This solution contains 0.20mgIT, 0.06nmgBIIA, 0.0GGagFG per liter. 10.12 Color developer: 7.0% static solution of 2.5-dichloro-1,3-dihydro-1-imide (2g/L). 11 Receiver
11. 1 Vacuum distillation device,
11.2 Length of the tube concentration bottle:
11.3 Layer folding Kun:
) 24 nx6 r:x4 er:
h)20rmx13rmRrm.
11.4 Glass collection: 5cmx20.13crx23
11.5 Micro syringe, 0.0]..
12 Analysis steps
-2.1.1 Vegetable oil (butter oil, soybean oil, soybean oil, peptide oil), weigh 5,U centrifuge 1, add 5,U centrifuge 10mlH, add 5mi1. Efficient 2ni. Huixin 3r/mi10mr/uin5ir absorb all the supernatant 2s. Apply, if more than one extraction, extract again every time, select to scale. 0m, electrostatic extract was placed in a concentrated stream, reduced pressure in 40% water to 0.5, prepared by mixing 2.1.2 ml of H2O, take 5.9 ml of H2O and put it in a conical flask with a pressure gauge, add 23.0 ml of methanol and condense it in water for 7s. After the condensate is completely dissolved, place the conical flask together with the condensate in a water bath and shake for 30 min. Then put it in a water bath and cool it down for 30 min (water bath, make the oil layer in the container, and place the conical flask in a cold chain tube in the water bath). Pass the oil and other extracts through a paper filter into a receiving bottle, then add the condensate to the source at 25 pm, repeat the extraction, and add the second alcohol extract, spray the dose into the stomach, wait for the rate to rise, and absorb 1 ml of alcohol at 30 pm.
Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.
- Recommended standards
- GB/T 2546-1988 Nomenclature of polypropylene and propylene copolymer materials
- JB/T 79.1-1994 Raised face integral cast steel pipe flange
- JB/T 9046-1999 Grille Decontamination Machine
- JB/T 7948.8-1999 Chemical analysis method for melting flux - Determination of phosphorus content by molybdenum blue photometry
- JB/T 9039-1999 Electromagnetic double-roller high-intensity magnetic separator
- JB/T 2001.68-1999 Types and dimensions of single pipe clamps for water systems
- GB/T 8754-1988 Aluminium and aluminium alloy anodic oxidation - Application of the breakdown potential test method to test insulation
- GB/T 40035-2021 Basic requirements for bilingual parallel corpus processing service
- GB/T 19622-2004 Labor quota for urban rail transit subway projects
- SY/T 10018-1998 Technical Guide for Marine Positioning Data Processing
- GB/T 5224-2003 Steel strand for prestressed concrete
- SJ/T 11125-1997 Encapsulation materials of epoxy series for use in electronic components
- SL/T 220-1998 Determination of trace copper, zinc, cadmium and lead in water - Flow injection atomic absorption spectrophotometry SL/T 220-98
- GB 12734-2003 汽车同步带
- JB/T 6773-1993 Resistivity test method for metal graphite products
Please remember: "bzxz.net" is the combination of the first letters of the Chinese pinyin of the four Chinese characters "standard download" and the international top-level domain name ".net". ©2024 Standard download websitewww.bzxz.net Mail:bzxznet@163.com