首页 购物车 询价 公司简介 购买流程 英文样品
梧三标准英文版 外资企业诚信经营, 增值税发票对公账户, 现货的9秒下载

GB 5009.259-2023英文版

标准搜索结果: 'GB 5009.259-2023英文版'
标准号码内文价格(元)第2步交付天数[PDF]标准名称相关标准
GB 5009.259-2023 英文版 1195 购买全文 现货, 9秒内下载 食品安全国家标准 食品中生物素的测定 GB 5009.259-2023

PDF提取页预览 (海外母公司返销,购买全文9秒自动发货,有发票)
标准编号: GB 5009.259-2023 (GB5009.259-2023)
中文名称: 食品安全国家标准 食品中生物素的测定
英文名称: (National food safety standards Determination of sialic acid in food)
行业: 国家标准
中标分类: X09
字数估计: 15,130
发布日期: 2023-09-06
实施日期: 2024-03-06
发布机构: 中华人民共和国国家卫生健康委员会、国家市场监督管理总局
范围: 本标准规定了食品中唾液酸的测定方法。本标准第一法液相色谱-紫外检测法适用于燕窝及其制品中结合态唾液酸的测定,第二法液相色谱-荧光检测法和第三法液相色谱-质谱/质谱法适用于液态乳、乳粉、糕点、饮料中唾液酸的测定。

GB 5009.259-2023 中文版: 食品安全国家标准 食品中生物素的测定
GB 5009.259-2023 英文版: (National food safety standards Determination of biotin in food)
中 华 人 民 共 和 国 国 家 标 准
食品安全国家标准
食品中生物素的测定
2023-09-06发布
2024-03-06实施
中华人民共和国国家卫生健康委员会
国 家 市 场 监 督 管 理 总 局 发 布
前言
本标准代替GB 5009.259-2016《食品安全国家标准 食品中生物素的测定》。
本标准与GB 5009.259-2016相比,主要变化如下:
---增加了第一法 液相色谱-串联质谱法,微生物法调整为第二法;
---第二法 微生物法增加了微孔板培养法;
---修改了标准的适用范围、样品类别和前处理方法;
---修改了标准曲线和样品提取液制备的表述方式;
---修改了检出限、定量限和线性范围。
食品安全国家标准
食品中生物素的测定
1 范围
本标准规定了食品中生物素的测定方法。
第一法 液相色谱-串联质谱法适用于调制乳粉、特殊膳食用食品中生物素的测定。
第二法 微生物法适用于食品中生物素的测定。
第一法 液相色谱-串联质谱法
2 原理
试样经溶解提取,对含淀粉试样经淀粉酶酶解后,经蛋白沉淀、离心过滤后,C18反相色谱柱分离,采
用液相色谱-串联质谱多离子反应监测方式检测,同位素稀释内标法定量。
3 试剂和材料
除非另有说明,本方法所用试剂均为分析纯,水为GB/T 6682规定的一级水。
3.1 试剂和材料
3.1.1 甲酸(HCOOH):色谱纯。
3.1.2 乙腈(CH3CN):色谱纯。
3.1.3 乙醇(CH3CH2OH):色谱纯。
3.1.4 甲酸铵(HCOONH4):色谱纯。
3.1.5 高氯酸(HClO4):70%~72%。
3.1.6 氢氧化钠(NaOH):纯度≥99.9%。
3.1.7 淀粉酶:Taka-淀粉酶,CAS:9001-19-8,酶活力≥100U/mg。
3.2 试剂配制
3.2.1 0.1%甲酸-10mmol/L甲酸铵水溶液:称取0.63g甲酸铵,用100mL水溶解后,转移至
1000mL试剂瓶中,加入1mL甲酸,以水稀释至1000mL,摇匀备用。
3.2.2 氢氧化钠溶液(2mol/L):称取8.00g氢氧化钠于烧杯中,加入100mL水溶解,摇匀备用。
3.2.3 乙醇溶液(50%):准确量取500mL乙醇于1000mL试剂瓶中,以水稀释至1000mL,摇匀
备用。
3.3 标准品
3.3.1 生物素标准品(C10H16N2O3S):CAS:58-85-5,纯度≥98%,或经国家认证并授予标准物质证书
的标准物质。
3.3.2 生物素-D4(C10D4H12N2O3S):CAS:1217850-77-5,纯度≥98%。
3.4 标准溶液配制
3.4.1 生物素标准储备液(100μg/mL):根据纯度换算精确称取10.00mg生物素标准品(精确至
0.01mg),用乙醇溶液(50%)溶解、定容至100mL。溶液转移至棕色玻璃瓶中,-20℃下密封保存,有
效期3个月。
3.4.2 生物素标准中间液(10μg/mL):准确吸取5.00mL生物素标准储备液(100μg/mL)至50mL
容量瓶,用乙醇溶液(50%)定容至50mL。溶液转移至棕色玻璃瓶中,-20℃下密封保存,有效期
3个月。
3.4.3 生物素标准中间液(1μg/mL):准确吸取1.00mL生物素标准中间液(10μg/mL)至10mL容
量瓶,用乙醇溶液(50%)定容至10mL。溶液转移至棕色玻璃瓶中,-20℃下密封保存,有效期3个月。
3.4.4 生物素标准工作液(100ng/mL):准确吸取1.00mL标准中间液(1μg/mL),用流动相A定容至
10mL。溶液转移至棕色玻璃瓶,4℃下密封保存,有效期1个月。
3.4.5 生物素标准工作液(10ng/mL):准确吸取1.00mL生物素标准工作液(100ng/mL),用流动相
A定容至10mL。临用现配。
3.5 同位素内标溶液配制
3.5.1 生物素-D4 同位素内标储备液(100μg/mL):准确称取10.00mg(精确至0.01mg)生物素内
标,以乙醇溶液(50%)溶解、定容至100mL。溶液转移至棕色玻璃瓶中,-20℃下密封保存,有效期
3个月。
3.5.2 生物素-D4 同位素内标工作液(1μg/mL):准确吸取1.00mL标准储备液(100μg/mL),用流动
相A定容于100mL。临用现配。
3.6 标准系列工作液配制
分别准确吸取适量生物素标准工作液于10mL容量瓶中,准确加入生物素-D4 同位素内标工作液
(1μg/mL)150μL,用流动相 A 定容至刻度,使标准系列生物素的质量浓度分别为1.0ng/mL、
2.0ng/mL、5.0ng/mL、10ng/mL、15ng/mL、20ng/mL和25ng/mL,每个系列溶液中同位素的质量
浓度为15ng/mL。临用现配。
4 仪器和设备
4.1 液相色谱-串联质谱仪。
4.2 天平:感量分别为0.001g和0.01mg。
4.3 恒温水浴锅:25℃~100℃。
4.4 pH计:精度0.01。
4.5 超声波振荡器。
4.6 涡旋混合器:600r/min~3200r/min。
4.7 高速离心机:≥10000r/min。
4.8 2mm孔径试验筛(选用)。
5 分析步骤
5.1 样品制备
5.1.1 固体样品
采样量需大于0.5kg。非均匀样品用高速粉碎机将其粉碎至全部通过2mm孔径试验筛,混合均
匀后缩分至100g,储存于广口瓶中,密封保存,供检测用。均匀性样品直接混匀,供检测用。
5.1.2 半固体样品
采样量需大于0.5kg。需至少采集3个包装(同一批次),将所有样品在一个容器中匀浆混匀后,其
中任意的100g储存于广口瓶中,密封保存,供检测用。
5.1.3 液体样品
意的100mL储存于广口瓶中,密封保存,供检测用。
5.2 样品前处理
5.2.1 不含淀粉试样
准确称取样品2g~5g(精确至0.001g),置于50mL离心管中,加入750μL同位素内标工作液
后,加入30mL温水(35℃~40℃),振荡混匀,超声提取15min。取出后迅速冷却至室温,用高氯酸调
节pH约为1.6。在4℃下,以8500r/min离心10min,经玻璃纤维过滤后用氢氧化钠溶液调节pH为
4.6±0.1,样液转移至50mL容量瓶,用水定容至刻度,混匀后移取1.5mL提取液至2mL离心管
中,在10000r/min下离心10min,样品溶液经0.22μm水系滤膜过滤,上机分析。
5.2.2 含淀粉试样
同位素内标工作液后,加入30mL温水(35℃~40℃),振荡混匀,放置50℃~60℃培养箱内约
30min,取出后超声提取15min。取出后迅速冷却至室温,用高氯酸调节pH约为1.6。在4℃下,以
8500r/min离心10min,经玻璃纤维过滤后用氢氧化钠溶液调节pH为4.6±0.1,样液转移至50mL
容量瓶,用水定容至刻度,混匀后移取1.5mL提取液至2mL离心管中,在10000r/min下离心
10min,样品溶液经0.22μm水系滤膜过滤,上机分析。
5.3 仪器测定参考条件
5.3.1 色谱参考条件如下:
a) 色谱柱:C18柱(柱长100mm,柱内径2.1mm,填料粒径1.7μm),或相当者;
b) 流动相A为0.1%甲酸-10mmol/L甲酸铵水溶液;流动相B为乙腈;
d) 柱温:35℃;
e) 进样体积:10μL;
f) 梯度洗脱条件见表1。
5.3.2 质谱参考条件如下:
a) 电离模式:ESI+;
b) 监测方式:多离子反应监测(MRM),参数见表2;
c) 毛细管电压:3.1kV;
d) 离子源温度:150℃;
e) 辅助气温度:350℃;
5.4 定性
试样中生物素的色谱峰的保留时间与相应标准溶液色谱峰的保留时间相比较,变化范围应在±
2.5%之内。
所选择的离子均出现,而且同一检测批次,样品中生物素的两个子离子的相对丰度与浓度相当的标
准溶液的相对丰度相比,其允许偏差不超过表3规定的范围。生物素标准溶液质谱扫描图及 MRM 色
谱图参见附录A。
5.5 标准曲线的制作
将生物素标准系列工作液浓度由低到高依次注入液相色谱-串联质谱仪中,以生物素浓度与生物素
内标浓度的比值为横坐标,以生物素与生物素内标峰面积比为纵坐标,绘制生物素的标准曲线。
试样中生物素的含量按式(1)计算。
7 精密度
在重复性条件下获得的2次独立测定结果的绝对差值不得超过算术平均值的15%。
8 其他
当称样量为5.0g时,定容体积为50mL,方法的检出限为0.300μg/100g,定量限为1.00μg/100g。
第二法 微生物法
9 原理
生物素是植物乳植杆菌(Lactiplantibacillusplantarum)生长所必需的营养素,在生物素测定培养
基中,植物乳植杆菌的生长与生物素的含量呈相关性,根据生物素含量与吸光度的标准曲线计算出试样
10 试剂和材料
除非另有规定,本方法所用试剂均为分析纯,水为GB/T 6682规定的二级水或一级水。
10.1 菌株
植物乳植杆菌(Lactiplantibacillusplantarum)[原植物乳杆菌(Lactobacillusplantarum)]ATCC
8014,或等效菌株。
10.2 培养基
10.2.1 乳酸杆菌琼脂培养基:见附录B中B.1。
10.2.2 乳酸杆菌肉汤培养基:见附录B中B.2。
10.2.3 生物素测定用培养基:见附录B中B.3。
10.3 试剂
10.3.1 无水乙醇(C2H5OH)。
10.3.2 硫酸(H2SO4):95%~98%。
10.3.3 氢氧化钠(NaOH)。
10.3.4 氯化钠(NaCl)。
10.4 试剂配制
10.4.1 乙醇溶液(50%):量取500mL无水乙醇,加入水中,定容至1000mL。
10.4.2 硫酸溶液A(3.0mol/L):量取163.2mL硫酸,加入水中,定容至1000mL。
10.4.3 硫酸溶液B(1.0mol/L):量取54.4mL硫酸,加入水中,定容至1000mL。
10.4.5 氢氧化钠溶液A(10mol/L):称取400g氢氧化钠,加入水中,溶解定容至1000mL。
10.4.6 氢氧化钠溶液B(0.1mol/L):吸取10mL氢氧化钠溶液A(10mol/L),加水定容至1000mL。
10.4.7 无菌生理盐水:称取8.5g氯化钠溶于1000mL蒸馏水中,分装于具塞试管,每管10mL,
121℃下高压灭菌15min。
注:配制硫酸溶液时,要在通风橱中配制,戴手套注意安全,将浓硫酸缓慢注入水中,并不断搅拌。
10.5 标准品
生物素标准品(C10H16N2O3S):CAS号为58-85-5,纯度≥98%,或经国家认证并授予标准物质证书
的标准物质。
10.6 标准溶液配制
按纯度称取,使生物素含量为50mg(精确至0.1mg),用乙醇溶液(50%)溶解定容至500mL。
10.6.2 生物素标准中间液(1μg/mL):吸取1.00mL生物素标准储备液(100μg/mL)至100mL容量
瓶,用乙醇溶液(50%)定容。
10.6.3 生物素标准使用液(10ng/mL):吸取1.00mL标准中间液(1μg/mL)至100mL容量瓶,用乙
醇溶液(50%)定容。
10.6.4 生物素标准曲线工作液:分两个浓度,高浓度溶液的浓度为0.2ng/mL;低浓度溶液的浓度为
0.1ng/mL。从使用液中(10ng/mL)吸取2次各5.00mL,用水分别定容到250mL和500mL。
注:所有标准溶液要用棕色试剂瓶冷藏于冰箱内(2℃~8℃),标准储备液保存期12个月,中间液保存期6个
月,标准使用液临用现配。
除微生物实验室常规灭菌及培养设备外,其他设备和材料如下。
11.1 分析天平:感量分别为0.001g和0.1mg。
11.2 离心机:3000r/min~5000r/min。
11.3 涡旋混合器。
11.4 pH计:精度为0.01。
11.5 恒温培养箱:36℃±1℃。
11.6 分光光度计:540nm~660nm。
11.7 酶标仪:540nm~660nm。
11.8 冰箱:2℃~8℃。
11.10 定量滤纸:直径90mm。
11.11 试管:18mm×180mm。
11.12 容量瓶:容量100mL、250mL和500mL。
11.13 单刻度移液管:1mL、5mL和10mL。
11.14 刻度吸管:5mL(具0.1mL刻度)。
11.15 玻璃漏斗:直径100mm。
11.16 锥形瓶:容量250mL。
11.17 烧杯:容量100mL。
11.18 分液器:0mL~10mL。

GB 5009.259-2023
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
National Food Safety Standard - Determination of Biotin in
Foods
ISSUED ON. SEPTEMBER 6, 2023
IMPLEMENTED ON. MARCH 6, 2024
Issued by. National Health Commission of the People’s Republic of China;
State Administration for Market Regulation.
Table of Contents
Foreword... 3
1 Scope... 4
Method I - Liquid Chromatography - Tandem Mass Spectrometry... 4
2 Principle... 4
3 Reagents and Materials... 4
4 Instruments and Equipment... 6
5 Analytical Procedures... 6
6 Expression of Analysis Results... 9
7 Precision... 10
8 Others... 10
Method II - Microbiological Method... 10
9 Principle... 10
10 Reagents and Materials... 10
11 Instruments and Equipment... 12
12 Analytical Procedures... 13
13 Expression of Analysis Results... 18
14 Precision... 19
15 Others... 19
Appendix A Mass Spectrum Scan and MRM Chromatogram of Biotin Standard
Solution... 20
Appendix B Preparation of Culture Medium... 21
National Food Safety Standard - Determination of Biotin in
Foods
1 Scope
This Standard specifies the methods for the determination of biotin in foods.
Method 1 - liquid chromatography - tandem mass spectrometry is applicable to the
determination of biotin in prepared milk powder and special dietary foods.
Method 2 - microbiological method is applicable to the determination of biotin in foods.
Method I - Liquid Chromatography - Tandem Mass
Spectrometry
2 Principle
The specimen is dissolved and extracted, and the starch-containing specimen is subject to
enzymatic hydrolysis by amylase, protein precipitation and centrifugal filtration, and separated
on a C18 reversed-phase chromatography column. Adopt the liquid chromatography - tandem
mass spectrometry multi-ion reaction monitoring mode for detection, and the isotope dilution
internal standard method for quantitative determination.
3 Reagents and Materials
Unless it is otherwise specified, the reagents used in this Method are all analytically pure, and
the water is Grade-1 water specified in GB/T 6682.
3.1 Reagents and Materials
3.1.1 Formic acid (HCOOH). chromatographically pure.
3.1.2 Acetonitrile (CH3CN). chromatographically pure.
3.1.3 Ethanol (CH3CH2OH). chromatographically pure.
3.1.4 Ammonium formate (HCOONH4). chromatographically pure.
3.1.5 Perchloric acid (HClO4). 70% ~ 72%.
3.1.6 Sodium hydroxide (NaOH). purity  99.9%.
3.1.7 Amylase. Taka-amylase, CAS. 9001-19-8, enzyme activity  100 U/mg.
3.2 Preparation of Reagents
3.2.1 0.1% formic acid-10 mmol/L ammonium formate aqueous solution. weigh-take 0.63 g of
ammonium formate, use 100 mL of water to dissolve it, then, transfer it into a 1,000 mL reagent
bottle, add 1 mL of formic acid, use water to dilute to 1,000 mL, shake it well and reserve it for
later use.
3.2.2 Sodium hydroxide solution (2 mol/L). weigh-take 8.00 g of sodium hydroxide in a beaker,
add 100 mL of water to dissolve it, shake it well and reserve it for later use.
3.2.3 Ethanol solution (50%). accurately measure-take 500 mL of ethanol into a 1,000 mL
reagent bottle, use water to dilute it to 1,000 mL, shake it well and reserve it for later use.
3.3 Reference Material
3.3.1 Biotin reference material (C10H16N2O3S). CAS. 58-85-5, purity  98%, or a standard
substance certified by the state and awarded a reference material certificate.
3.4 Preparation of Standard Solutions
3.4.1 Biotin standard stock solution (100 g/mL). in accordance with purity conversion,
accurately weigh-take 10.00 mg of biotin reference material (accurate to 0.01 mg), use ethanol
solution (50%) to dissolve it and reach a constant volume of 100 mL. Transfer the solution to a
brown glass bottle, seal and store it at 20 C. It shall remain valid for 3 months.
3.4.2 Biotin standard intermediate solution (10 g/mL). accurately draw-take 5.00 mL of biotin
standard stock solution (100 g/mL) into a 50 mL volumetric flask; use ethanol solution (50%)
to reach a constant volume of 50 mL. Transfer the solution to a brown glass bottle, seal and
store it at 20 C. It shall remain valid for 3 months.
standard intermediate solution (10 g/mL) into a 10 mL volumetric flask; use ethanol solution
(50%) to reach a constant volume of 10 mL. Transfer the solution to a brown glass bottle, seal
and store it at 20 C. It shall remain valid for 3 months.
3.4.4 Biotin standard working solution (100 ng/mL). accurately draw-take 1.00 mL of the
standard intermediate solution (1 g/mL) and use mobile phase A to reach a constant volume
of 10 mL. Transfer the solution to a brown glass bottle, seal and store it at 4 C. It shall remain
valid for 1 month.
3.4.5 Biotin standard working solution (10 ng/mL). accurately draw-take 1.00 mL of biotin
standard working solution (100 ng/mL) and use mobile phase A to reach a constant volume of
non-uniform samples, until all of them pass through a 2 mm aperture test sieve. After evenly
mixing, divide the samples to 100 g and store in a wide-mouth bottle. Seal it and reserve it for
testing. For uniform samples, directly evenly mix them and reserve them for testing.
5.1.2 Semi-solid samples
The sampling size needs to be greater than 0.5 kg. At least 3 packages (from the same batch)
need to be collected. After all samples are homogenized and evenly mixed in a container, store
any 100 g of them in a wide-mouth bottle. Seal it and reserve it for testing.
5.1.3 Liquid samples
The sampling size needs to be greater than 0.5 L. At least 3 packages (from the same batch)
them in a wide-mouth bottle. Seal it and reserve it for testing.
5.2 Pre-treatment of Samples
5.2.1 Starch-free specimens
Accurately weigh-take 2 g ~ 5 g (accurate to 0.001 g) of sample and place it in a 50 mL
centrifuge tube. Add 750 L of isotope internal standard working solution, then, add 30 mL of
warm water (35 C ~ 40 C); oscillate and evenly mix it, and conduct ultrasonic extraction for
15 min. After taking it out, quickly cool it to room temperature, and use perchloric acid to adjust
pH to about 1.6.At 4 C, at 8,500 r/min, centrifuge for 10 min. After filtering through glass
fiber, use sodium hydroxide solution to adjust pH to 4.6  0.1.Transfer the sample solution to
Then, transfer-take 1.5 mL of the extracting solution to a 2 mL centrifuge tube. At 10,000 r/min,
centrifuge for 10 min. Filter the sample solution through a 0.22 m water-based filter membrane
and analyze it on the machine.
5.2.2 Starch-containing specimens
Accurately weigh-take 2 g ~ 5 g (accurate to 0.001 g) of sample and place it in a 50 mL
centrifuge tube. Add 1% of the sample amount of amylase and 750 L of isotope internal
standard working solution, then, add 30 mL of warm water (35 C ~ 40 C), oscillate and evenly
mix it. Place it in a 50 C ~ 60 C incubator for about 30 min, take it out and perform ultrasonic
extraction for 15 minutes. After taking it out, quickly cool it to room temperature, and use
filtering through glass fiber, use sodium hydroxide solution to adjust pH to 4.6  0.1.Transfer
the sample solution to a 50 mL volumetric flask, use water to reach a constant volume to the
scale and evenly mix it. Then, transfer-take 1.5 mL of the extracting solution to a 2 mL
centrifuge tube. At 10,000 r/min, centrifuge for 10 min. Filter the sample solution through a
0.22 m water-based filter membrane and analyze it on the machine.
5.3 Reference Conditions of Instrument Determination
X---the content of biotin in the specimen, expressed in (g/100 g);
ρ---the mass concentration of biotin in the specimen calculated based on the standard curve,
expressed in (ng/mL);
m---the mass of the specimen, expressed in (g);
100---the conversion factor for the specimen weight per 100 g;
1,000---the conversion factor for converting ng into g in the specimen.
The results shall retain 3 significant figures.
7 Precision
The absolute difference between the results of two independent determinations obtained under
repeatability conditions shall not exceed 15% of the arithmetic mean.
8 Others
When the sampling size is 5.0 g and the constant volume is 50 mL, the detection limit of this
Method II - Microbiological Method
9 Principle
Biotin is an essential nutrient for the growth of Lactiplantibacillus plantarum. In the biotin
determination culture medium, the growth of Lactiplantibacillus plantarum is correlated with
the biotin content. In accordance with the standard curve of biotin content and absorbance,
calculate the biotin content in the specimen.
10 Reagents and Materials
Unless it is otherwise specified, the reagents used in this Method are all analytically pure, and
the water is Grade-2 or Grade-1 water specified in GB/T 6682.
Lactiplantibacillus plantarum [the former Lactobacillus plantarum] ATCC 8014, or equivalent
strain.
10.2 Culture Media
10.2.1 Lactobacillus agar culture medium. see B.1 in Appendix B.
10.2.2 Lactobacillus broth culture medium. see B.2 in Appendix B.
10.2.3 Medium for biotin determination. see B.3 in Appendix B.
NOTE. commercially available synthetic media can be used and operated in accordance with the
instructions.
10.3 Reagents
10.3.2 Sulfuric acid (H2SO4). 95% ~ 98%.
10.3.3 Sodium hydroxide (NaOH).
10.3.4 Sodium chloride (NaCl).
10.4 Preparation of Reagents
10.4.1 Ethanol solution (50%). measure-take 500 mL of absolute ethanol, add it to water and
reach a constant volume of 1,000 mL.
10.4.2 0Sulfuric acid solution A (3.0 mol/L). measure-take 163.2 mL of sulfuric acid, add it to
water and reach a constant volume of 1,000 mL.
10.4.3 Sulfuric acid solution B (1.0 mol/L). measure-take 54.4 mL of sulfuric acid, add it to
10.4.4 Sulfuric acid solution C (0.5 mol/L). measure-take 27.2 mL of sulfuric acid, add it to
water and reach a constant volume of 1,000 mL.
10.4.5 Sodium hydroxide solution A (10 mol/L). weigh-take 400 g of sodium hydroxide, add it
to water and reach a constant volume of 1,000 mL.
10.4.6 Sodium hydroxide solution B (0.1 mol/L). draw-take 10 mL of sodium hydroxide
solution A (10 mol/L), add water to reach a constant volume of 1,000 mL.
10.4.7 Sterile physiological saline. weigh-take 8.5 g of sodium chloride and dissolve it in 1,000
mL of distilled water, divide it into stoppered test tubes, with 10 mL in each tube. At 121 C,
perform autoclaved sterilization for 15 min.
attention to safety. Slowly inject concentrated sulfuric acid into water and keep stirring it.
10.5 Reference Material
11.8 Refrigerator. 2 C ~ 8 C.
11.9 Sterile microplate.
11.10 Quantitative filter paper. with a diameter of 90 mm.
11.11 Test tube. 18 mm  180 mm.
11.12 Volumetric flask. with a capacity of 100 mL, 250 mL and 500 mL.
11.13 One-mark pipette. 1 mL, 5 mL and 10 mL.
11.14 Graduated pipette. 5 mL (with a scale of 0.1 mL).
11.16 Conical flask. with a capacity of 250 mL.
11.17 Beaker. with a capacity of 100 mL.
11.18 Dispenser. 0 mL ~ 10 mL.
11.19 Micropipette. 1,000 L and 200 L.
11.20 Sterile centrifuge tube. 1.5 mL.
11.21 Syringe filter. with an aperture of 0.22 m.
NOTE. the cleaned glassware and metal appliances shall be dried at 200 C ~ 250 C for 1 h ~ 2 h.
12 Analytical Procedures
12.1 Preparation of Test Bacterial Suspension
   
相关标准:  GB 5009.265-2021  GB 5009.240-2023
 
宁德梧三商贸有限公司 (外资企业) | 纳税人识别号:91350900MA32WE2Q2X | 营业执照:营业执照证书
联系电邮(郑文锐销售经理): Sales@gb-gbt.cn | 增值税普通发票 /专用发票样品
对公开户银行:中国建设银行 | 账号:35050168730700000955 | 账户名称:宁德梧三商贸有限公司
CIPS大额行号 (海外汇来款用CIPS系统):105403500207 对公银行账号证书
声明:本网站翻译主要根据参考国家市监总局、卫生部、环保部等各部委总局(机构)发布的全文公开(中文内容)。
网站备案许可:闽ICP备19012676号 http://www.beian.miit.gov.cn
隐私   ·  优质产品   ·  退款政策   ·  公平交易   ·  关于我们