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医用输液、输血、注射器具检验方法 第1部分：化学分析方法
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GBT 14233.1-2022
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标准编号: GB/T 14233.1-2022 (GB/T14233.1-2022)
中文名称: 医用输液、输血、注射器具检验方法 第1部分：化学分析方法
英文名称: Test methods for infusion, transfusion, injection equipments for medical use -- Part 1: Chemical analysis methods
行业: 国家标准 (推荐)
中标分类: C31
国际标准分类: 11.040.20
字数估计: 18,158
发布日期: 2022-10-14
实施日期: 2023-11-01
旧标准 (被替代): GB/T 14233.1-2008
起草单位: 山东省医疗器械和药品包装检验研究院、苏州百特医疗用品有限公司、山东威高集团医用高分子制品股份有限公司
归口单位: 全国医用输液器具标准化技术委员会(SAC/TC 106)
提出机构: 国家药品监督管理局
发布机构: 国家市场监督管理总局、国家标准化管理委员会
GB/T 14233.1-2022: 医用输液、输血、注射器具检验方法 第1部分：化学分析方法
GB/T 14233.1-2022 英文名称: Test methods for infusion, transfusion, injection equipments for medical use -- Part 1: Chemical analysis methods
ICS 11.040.20
CCSC31
中华人民共和国国家标准
代替GB/T 14233.1-2008
2022-10-12发布
2023-11-01实施
国 家 市 场 监 督 管 理 总 局
国 家 标 准 化 管 理 委 员 会 发 布
1 范围
本文件规定了医用输液、输血、注射器具化学分析方法。
本文件适用于医用高分子材料制成的医用输液、输血、注射及配套器具的化学分析,其他医用高分
子制品的化学分析亦可参照使用。
5 检验液溶出物分析方法
5.1 澄清度和色泽
5.1.1 澄清度
按《中华人民共和国药典》(2020年版)四部0902澄清度检查法进行。
5.1.2 色泽
按《中华人民共和国药典》(2020年版)四部0901溶液颜色检查法进行。
5.2 还原物质(易氧化物)
5.2.1 方法一:直接滴定法
5.2.1.1 原理
高锰酸钾是强氧化剂,在酸性介质中,高锰酸钾与还原物质作用,MnO4-被还原成 Mn2+:
5.2.1.2 溶液配制
硫酸溶液:量取128mL硫酸,缓缓注入500mL水中,冷却后稀释至1000mL。
草酸钠溶液:称取105℃~110℃干燥恒重的草酸钠6.700g,加水溶解并稀释至1000mL。
草酸钠溶液:临用前取草酸钠溶液加水稀释10倍。
高锰酸钾标准滴定溶液:按GB/T 601中方法进行配制和标定。
高锰酸钾标准滴定溶液:临用前,取高锰酸钾标准滴定溶液
[加水稀释10倍。必要时煮沸,放冷,过滤,再标定其浓度。
5.2.1.3 试验步骤
精确量取检验液20mL,置于锥形瓶中,精确加入产品标准中规定浓度的高锰酸钾标准滴定溶液
3mL,硫酸溶液5mL,加热至沸并保持微沸10min,稍冷后精确加入对应浓度的草酸钠溶液5mL,置
于水浴上加热至75℃~80℃,用规定浓度的高锰酸钾标准滴定溶液滴定至显微红色,并保持30s不褪
色为终点,同时与同批空白对照液相比较。
5.2.1.4 结果计算
还原物质(易氧化物)含量以消耗高锰酸钾溶液的量表示,按式(1)计算:
5.2.2 方法二:间接滴定法
5.2.2.1 原理
水浸液中含有的还原物质在酸性条件下加热时,被高锰酸钾氧化,过量的高锰酸钾将碘化钾氧化成
碘,而碘被硫代硫酸钠还原。
5.2.2.2 溶液配制
硫酸溶液:量取128mL硫酸,缓缓注入500mL水中,冷却后稀释至1000mL。
高锰酸钾溶液:同5.2.1.2。
高锰酸钾溶液:同5.2.1.2。
淀粉指示液:称取0.5g淀粉溶于100mL水中,加热煮沸后冷却备用。
硫代硫酸钠标准滴定溶液:按GB/T 601中方法进行配制和标定。
硫代硫酸钠标准滴定溶液:临用前取硫代硫酸钠标准滴定溶液用新煮沸并冷却的水稀释10倍。
5.2.2.3 试验步骤
精确量取检验液10mL,加入250mL碘量瓶中,精密加入硫酸溶液1mL和产品标准中规定浓度
的高锰酸钾溶液10mL,煮沸3min,迅速冷却,加碘化钾0.1g,密塞,摇匀。立即用相同浓度的硫代硫
酸钠标准滴定溶液滴定至淡黄色,再加5滴淀粉指示液,继续用硫代硫酸钠标准滴定溶液滴定至无色。
用同样的方法滴定空白对照液。
也可取检验液20mL。检验液取20mL时,高锰酸钾溶液也加20mL,硫酸溶液加2mL,碘化钾加1.0g。
5.2.2.4 结果计算
还原物质(易氧化物)的含量以消耗高锰酸钾溶液的量表示,按式(2)计算:
5.3 氯化物
5.3.1 原理
氯离子在酸性条件下与硝酸银反应生成氯化银沉淀。
5.3.2 溶液配制
氯标准贮备液(0.1mg/mL):称取500℃~600℃灼烧至恒重的氯化钠0.165g,溶于水中,移入
1000mL容量瓶中,稀释至刻度。
氯标准溶液:临用前精确量取氯标准贮备液稀释至所需浓度。
硝酸银试液(17.5g/L):称取硝酸银1.75g,溶于水中,稀释至100mL,贮存于棕色瓶中。
硝酸溶液:取105mL硝酸,用水稀释至1000mL。
5.3.3 试验步骤
精确量取检验液10mL,加入50mL纳氏比色管中,加10mL稀硝酸 (溶液若不澄清,过滤,滤液
置于50mL纳氏比色管中),加水使成约40mL,即得供试液。
精确量取10mL氯标准溶液至另一支50mL纳氏比色管中,加10mL稀硝酸,加水使成约40mL,
摇匀,即得标准对照液。
在以上两试管中分别加入硝酸银试液1.0mL,用水稀释至50mL,在暗处放置5min,置黑色背景
上从比色管上方观察。供试液与标准对照液比浊。
供试溶液如带颜色,除另有规定外,可取供试溶液两份,分置50mL纳氏比色管中,一份中加硝酸
银试液1.0mL,摇匀,放置10min,如显浑浊,可反复过滤至滤液完全澄清,再加规定量的氯标准溶液与
水适量使成50mL,摇匀,在暗处放置5min,作为对照液;另一份中加硝酸银试液1.0mL与水适量使
成50mL,摇匀在暗处放置5min,按上述方法与对照溶液比较,即得。
5.4 酸碱度
5.4.1 方法一
取检验液和空白对照液,按照《中华人民共和国药典》(2020年版)四部0631pH值测定法分别测定
5.4.2 方法二
5.4.2.1 溶液配制
氢氧化钠标准滴定溶液:按GB/T 601的规定配制及标定。
氢氧化钠标准滴定溶液:临用前取氢氧化钠标准滴定溶液加水稀释10倍。
盐酸标准滴定溶液:按GB/T 601的规定配制及标定。
盐酸标准滴定溶液:临用前取盐酸标准滴定溶液加水稀释10倍。
指示剂:溶解0.2g甲基红和0.1g亚甲基蓝于100mL乙醇(体积分数为95%)中。
5.4.2.2 试验步骤
精确量取20mL检验液置100mL磨口瓶中,加入0.1mLTashiro指示剂,如果溶液颜色呈紫色,
以消耗氢氧化钠标准滴定溶液或盐酸标准滴定溶液的体积(以毫升为单位)作为检验结果。
5.4.3 方法三
5.4.3.1 溶液配制
氢氧化钠标准滴定溶液:同5.4.2.1。
氢氧化钠标准滴定溶液:同5.4.2.1。
盐酸标准滴定溶液:同5.4.2.1。
盐酸标准滴定溶液:同5.4.2.1。
酚酞指示液(10g/L):称取1g酚酞,溶于乙醇(体积分数为95%)并稀释至100mL。
甲基红指示液(1g/L):称取0.1g甲基红,溶于乙醇(体积分数为95%)并稀释至100mL。
向10mL检验液中加入2滴酚酞指示液,溶液不应呈红色。加入0.4mL的氢氧化钠标准滴定溶
液,应呈红色。加入0.8mL盐酸标准滴定溶液,红色应消失。加入5滴甲基红指示液,溶液应呈红色。
5.5 蒸发残渣
5.5.1 试验步骤
蒸发皿预先在105℃干燥至恒重。量取检验液50mL加入蒸发皿中,在水浴上蒸干并在105℃恒
温箱中干燥至恒重。同法测定空白对照液。
5.5.2 结果计算
按式(3)计算蒸发残渣的质量:
5.6 重金属总含量
5.6.1.1 原理
在弱酸性溶液中,铅、铬、铜、锌等重金属能与硫代乙酰胺作用生成不溶性有色硫化物。以铅为代表
制备标准溶液进行比色,测定重金属的总含量。
5.6.1.2 试剂及溶液配制
乙酸盐缓冲液(pH3.5):取乙酸铵25g,加水25mL溶解后,加盐酸溶液(7mol/L)38mL,用盐酸
溶液(2mol/L)或氨溶液(5mol/L)准确调节pH值至3.5(电位法指示),用水稀释至100mL,即得。
硫代乙酰胺试液:取硫代乙酰胺4g,加水使溶解成100mL,置冰箱中保存。临用前取混合液[由氢
氧化钠(1mol/L)15mL、水5mL及甘油20mL组成]5mL,加上述硫代乙酰胺溶液1mL,置水浴上加
热20s,冷却,立即使用。
容量瓶中,用水稀释至刻度。
铅标准溶液:临用前,精确量取铅标准贮备液,稀释至所需浓度。
5.6.1.3 试验步骤
精确量取检验液25mL于25mL纳氏比色管中,另取一支25mL纳氏比色管,加入铅标准液
25mL,于上述两支比色管中分别加入乙酸盐缓冲液(pH3.5)2mL,再分别加入硫代乙酰胺试液2mL,
摇匀,放置2min,置白色背景下从上方观察,比较颜色深浅。
检验液如显色,可在标准对照液中加入少量稀焦糖溶液或者其他无干扰的有色溶液,使之与检验液
颜色一致。再在检验液和标准对照液中各加入2mL硫代乙酰胺试液,摇匀,放置2min。在白色背景
下从上方观察,比较颜色深浅。检验液也可取10mL,则铅标准液加入量为10mL。
5.6.2.1 原理
在碱性溶液中,铅、铬、铜、锌等重金属能与硫化钠作用生成不溶性有色硫化物。以铅为代表制备标
准溶液进行比色,测定重金属的总含量。
5.6.2.2 溶液配制
氢氧化钠试液(43g/L):取氢氧化钠4.3g,加水使溶解成100mL,即得。
硫化钠试液(100g/L):临用前,称取硫化钠1g,加水使溶解成10mL,即得。
铅标准贮备液(0.1mg/mL):同5.6.1.2。
铅标准溶液:同5.6.1.2。
5.6.2.3 试验步骤
25mL,于上述两支比色管中分别加入氢氧化钠试液5mL,再分别加入硫化钠试液5滴,摇匀,置白色
背景下从上方观察,比较颜色深浅。
5.7 紫外吸光度
取检验液,必要时用0.45μm的微孔滤膜过滤,在5h内用1cm比色皿以空白对照液为参比,在规
定的波长范围内测定吸光度。
5.8 铵
5.8.1 原理
铵离子在碱性溶液中能与纳氏试剂反应生成黄色物质,通过与标准对照液比色,测定其铵含量。
5.8.2 溶液配制
纳氏试剂(碱性碘化汞钾试液):取碘化钾10g,加水10mL溶解后,缓缓加入二氯化汞的饱和水溶
液,随加随搅拌,至生成的红色沉淀不再溶解,加氢氧化钾30g溶解后,再加二氯化汞的饱和水溶液
1mL或1mL以上,并用适量的水稀释使成200mL,静置,使沉淀,即得。用时倾取上清液使用。检查:
取本液2mL,加入含氨0.05mg的水50mL中,应即时显黄棕色。
铵标准贮备液(0.1mg/mL):称取0.297g于105℃~110℃干燥至恒重的氯化铵,用水溶解并稀
释至1000mL。
铵标准溶液:临用前精确量取铵标准贮备液,稀释至所需浓度。
5.8.3 试验步骤
精确量取10mL检验液于25mL纳氏比色管中,另取一支25mL纳氏比色管,加入铵标准溶液
15mL,加入0.3mL纳氏试剂。
30s后进行检查,比较检验液与对照液颜色深浅。
5.9 部分重金属元素
5.9.1 原子吸收分光光度计法
5.9.1.1 仪器
原子吸收分光光度计,使用时应按仪器说明书操作。
5.9.1.2 分析方法 (标准曲线法)
在仪器推荐的浓度范围内,应制备至少5个含待测元素且浓度依次递增的标准溶液(不包括零点),
标准溶液浓度范围宜考虑待测物的浓度。然后以配制标准溶液用的溶剂为空白,依次测定各标准溶液
测定检验液和空白对照液,根据吸光度在标准曲线上查出相应浓度,计算元素的含量。
5.9.2 电感耦合等离子体发射光谱法和质谱法
5.9.2.1 仪器
电感耦合等离子体发射光谱仪、电感耦合等离子体质谱仪,使用时应按仪器说明书操作。
5.9.2.2 分析方法 (标准曲线法)
在仪器推荐的浓度范围内,应制备至少5个含待测元素且浓度依次递增的标准溶液(不包括零点),
标准溶液浓度范围宜考虑待测物的浓度。然后以配制标准溶液用的溶剂为空白,依次测定各标准溶液
的信号值,相对于浓度作标准曲线。
测定检验液和空白对照液,根据信号值在标准曲线上查出相应浓度,计算各元素的含量。
5.9.3.1 仪器
原子荧光光度计,使用时应按仪器说明书操作。
5.9.3.2 分析方法 (标准曲线法)
在原子荧光光度计推荐的浓度范围内,制备至少5个含待测元素且浓度依次递增的标准溶液(不包
括零点),标准溶液浓度范围宜考虑待测物的浓度。然后以配制标准溶液用的溶剂为空白,依次测定各
标准溶液的荧光强度,相对于浓度作标准曲线。
测定检验液和空白对照液,根据吸光度在标准曲线上查出相应浓度,计算元素的含量。
6 材料中重金属总含量分析方法
6.1 原理
液作标准进行比色,可测定它们的总含量。
6.2 试剂及溶液配制
按5.6.1.2进行。
6.3 检验液制备
取样品适量,切成5mm×5mm碎片,放入瓷坩埚内,缓缓炽灼至完全炭化,放冷,加入0.5mL~
1mL硫酸湿润,低温加热至硫酸蒸气消失后,加入硝酸0.5mL,蒸干,至氧化氮蒸气除尽后放冷。再在
500℃~600℃灼烧使之灰化,冷却后加入2mL盐酸,置水浴上蒸干后加水15mL。加酚酞试液一滴,
再滴入氨试液至上述溶液变成微红色为止。加乙酸盐缓冲液(pH3.5)2mL微热溶解后(如有残渣宜采
用滤纸过滤),将溶液转移至25mL纳氏比色管中,加水使成25mL检验液。
酸盐缓冲液(pH3.5)2mL与水15mL,微热溶解后将溶液转移至25mL纳氏比色管中,加一定量铅标
准溶液,再用水稀释成25mL作为标准对照液。
6.4 试验步骤
在检验液和标准对照液中各加入2mL硫代乙酰胺试液,摇匀,放置2min。在白色背景下从上方
观察,比较颜色深浅。
检验液如显色,可在标准对照液中加入少量稀焦糖溶液或者其他无干扰的有色溶液,使之与样品液颜色一致。
7 材料中部分重金属元素含量分析方法
7.1 原子吸收分光光度计法
7.1.1 试样消解
30mL,硫酸1.25mL,摇匀后放置过夜,置电热板上加热消解。若消解液处理至10mL左右时仍有未
分解物质或色泽变深,取下放冷,补加硝酸5mL~10mL,再消解至10mL左右观察,如此反复两三次,
注意避免炭化。冷却,加水25mL,再蒸发至冒硫酸白烟。冷却,用水将内容物转入50mL容量瓶中,
加水成50mL检验液。同法制备空白对照液。
7.1.1.2 干灰化:取样品1g~2g,精确称重,置于坩埚中。加质量浓度为150g/L的硝酸镁溶液10mL
混匀,低热蒸干,将氧化镁1g仔细覆盖在干渣上,炭化至无黑烟,再在550℃灰化4h。取出放冷,小心
加10mL盐酸(1+1)以中和氧化镁并溶解灰分(如有残渣宜采用滤纸过滤),转移至50mL容量瓶中,
加水成50mL检验液。同法制备空白对照液。
7.1.1.3 其他方法:根据样品成分及工艺合理制定。
原子吸收分光光度计,使用时应按仪器说明书操作。
7.1.3 分析方法 (标准曲线法)
在仪器推荐的浓度范围内,制备至少5个含待测元素且浓度依次递增的标准溶液(不包括零点),标
准溶液浓度范围宜考虑待测物的浓度。然后依次测定各标准溶液的吸光度,相对于浓度作标准曲线。
测定按7.1.1制备的检验液和空白对照液,根据吸光度在标准曲线上查出相应浓度,计算元素的含量。
7.2 电感耦合等离子体发射光谱法和质谱法
7.2.1 仪器
电感耦合等离子体发射光谱仪、电感耦合等离子体质谱仪,使用时应按仪器说明书操作。
7.2.2 分析方法 (标准曲线法)
准溶液浓度范围宜考虑待测物的浓度。然后依次测定各标准溶液的信号值,相对于浓度作标准曲线。
测定按7.1.1制备的检验液和空白对照液,根据信号值在标准曲线上查出相应浓度,计算各元素的含量。
7.3 原子荧光光谱法
7.3.1 仪器
原子荧光光度计,使用时应按仪器说明书操作。
7.3.2 分析方法
在仪器推荐的浓度范围内,制备至少5个含待测元素且浓度依次递增的标准溶液(不包括零点),标
准溶液浓度范围宜考虑待测物的浓度。然后依次测定各标准溶液的吸光度,相对于浓度作标准曲线。
测定检验液和空白对照液,根据吸光度在标准曲线上查出相应浓度,计算元素的含量。
8.1 试验步骤
取样品适量切成约为5mm×5mm,置于已灼烧至恒重的坩埚(m0)中,精确称重,记为m1。在通
风橱中缓缓灼烧至完全炭化,放冷。加0.5mL~1mL硫酸使其湿化,低温加热至硫酸蒸汽除尽,在
700℃~800℃灼烧至完全灰化。置于干燥器内放至室温,称重。再在700℃~800℃灼烧至恒重。称重,记为m2。
如需将残渣留作重金属检查,则灼烧温度应控制在500℃~600℃。
8.2 结果计算
按式(4)计算炽灼残渣的质量分数:
GB/T 14233.1-2022
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 11.040.20
CCS C 31
Replacing GB/T 14233.1-2008
Test Methods for Infusion, Transfusion, Injection Equipment
for Medical Use - Part 1: Chemical Analysis Methods
ISSUED ON: OCTOBER 12, 2022
IMPLEMENTED ON: NOVEMBER 1, 2023
Issued by: State Administration for Market Regulation;
Standardization Administration of the People’s Republic of China.
Table of Contents
Foreword ... 3
Introduction ... 5
1 Scope ... 6
2 Normative References ... 6
3 Terms and Definitions ... 6
4 General Rules ... 6
5 Analysis Methods of Extractable Matters of Test Solution ... 9
6 Analysis Method of Total Content of Heavy Metals in the Materials... 19
7 Content Analysis Methods of Some Heavy Metal Elements in the Materials ... 20
8 Residue on Ignition ... 22
9 Determination of Ethylene Oxide Residue - Gas Chromatography ... 23
Bibliography ... 27
Test Methods for Infusion, Transfusion, Injection Equipment
for Medical Use - Part 1: Chemical Analysis Methods
1 Scope
This document specifies the chemical analysis methods for the infusion, transfusion and
injection equipment for medical use.
This document is applicable to the chemical analysis of the infusion, transfusion, injection and
supporting equipment for medical use and made of medical polymer materials. The chemical
analysis of other medical polymer products can also take this document as a reference.
2 Normative References
The contents of the following documents constitute indispensable clauses of this document
through the normative references in this text. In terms of references with a specified date, only
versions with a specified date are applicable to this document. In terms of references without a
specified date, the latest version (including all the modifications) is applicable to this document.
GB/T 601 Chemical Reagent - Preparations of Standard Volumetric Solutions
GB/T 6682 Water for Analytical Laboratory Use - Specification and Test Methods
Pharmacopoeia of the People’s Republic of China (Version 2020) Four Volumes
3 Terms and Definitions
This document does not have terms or definitions that need to be defined.
4 General Rules
4.1 Overview
4.1.1 All analyses in this document are carried out in two parallel test groups; the results shall
be within the allowable relative deviation limit; the arithmetic mean shall be taken as the
determination result. If one is qualified and the other is disqualified, the average calculation
shall not be performed and the determination shall be re-performed.
4.1.2 Unless it is otherwise specified, all reagents used in this document are analytically pure.
4.1.3 Unless it is otherwise specified, the test water in this document shall comply with the
requirements of Grade-2 water in GB/T 6682.
4.1.4 The term “room temperature” used in this document refers to 10 C ~ 30 C.
4.1.5 The term “accurate weighing” used in this document refers to weighing accurate to 0.1
mg.
4.1.6 The term “accurate measuring” used in this document refers to measuring with a transfer
pipette that complies with the accuracy requirements specified in the corresponding national
standards.
4.1.7 Constant weight by gravimetric method means that the weight difference of the test
sample after two consecutive ignitions or dryings shall not exceed 0.3 mg.
4.1.8 Unless it is otherwise specified, the glass containers used in this document are all
borosilicate glass containers.
4.1.9 Most of the analysis methods provided in this document are non-specific analysis methods,
and these methods can be used for the preliminary assessment of chemical hazards of medical
devices. However, if there is a situation that does not comply with the preliminary expectations
in a specific test, it does not suggest that the actual risk is unacceptable, and specific analysis
methods need to be adopted to identify and evaluate the safety.
4.2 Preparation of Test Solution
4.2.1 The preparation of the test solution shall simulate the conditions (such as: the application
process as much as possible. The simulated extraction time shall not be less than the normal
use time of the product. When the product has been used for a long time (more than 24 h),
consideration should be given to prepare the test solution under accelerated test conditions, but
the feasibility and rationality need to be verified.
4.2.2 The methods used for the preparation of the test solution should try to extract all the tested
surfaces of the sample.
4.2.3 It is recommended to select the test solution preparation method in Table 1, and:
---If the sample preparation conditions in the brackets are used, it shall be indicated in the
product standard;
product may be subject to in clinical use. For polymers, the temperature shall be
selected below the glass transition temperature.
solution and dilute to the required concentration.
Silver nitrate test solution (17.5 g/L): weigh-take 1.75 g of silver nitrate, dissolve it in water,
dilute to 100 mL and store it in a brown bottle.
Nitric acid solution: take 105 mL of nitric acid and use water to dilute to 1,000 mL.
5.3.3 Test procedures
Accurately measure-take 10 mL of the test solution, add it to a 50 mL Nessler colorimetric tube;
add 10 mL of dilute nitric acid (if the solution is not clear, filter it and place the filtrate in a 50
obtained.
Accurately measure-take 10 mL of the chlorine standard solution to another 50 mL Nessler
colorimetric tube; add 10 mL of dilute nitric acid; add water to make it about 40 mL; shake it
well. Thus, the standard control solution is obtained.
In the above-mentioned two test tubes, respectively add 1.0 mL of silver nitrate test solution,
use water to dilute to 50 mL; place it in a dark place for 5 min; place it on a black background
and observe from above the colorimetric tube. Compare the turbidity of the test solution with
the standard control solution.
If the test solution is colored, unless it is otherwise specified, take two portions of the test
nitrate test solution to one portion, shake it well and let it stand for 10 min. If it becomes turbid,
repeatedly filter it, until the filtrate is completely clear. Then, add the specified amount of
chlorine standard solution and an appropriate amount of water to make it 50 mL; shake it well
and place it in the dark for 5 min; use it as the control solution. Add 1.0 mL of silver nitrate test
solution to another portion and an appropriate amount of water to make it 50 mL. Shake it well
and place it in the dark for 5 min. In accordance with the above-mentioned method, compare it
with the control solution. Thus, the solution is obtained.
5.4 pH
5.4.1 Method 1
determination method of Pharmacopoeia of the People’s Republic of China (Version 2020) Four
Volumes, respectively determine the pH value and take the difference between them as the test
result.
5.4.2 Method 2
5.4.2.1 Solution preparation
Sodium hydroxide standard titration solution [c (NaOH) = 0.1 mol/L]: in accordance with the
stipulations of GB/T 601, prepare and titrate it.
Sodium hydroxide standard titration solution [c (NaOH) = 0.01 mol/L]: before use, take the
sodium hydroxide standard titration solution [c (NaOH) = 0.1 mol/L] and add water to dilute
Hydrochloric acid standard titration solution [c (HCl) = 0.1 mol/L]: in accordance with the
stipulations of GB/T 601, prepare and titrate it.
Hydrochloric acid standard titration solution [c (HCl) = 0.01 mol/L]: before use, take the
hydrochloric acid standard titration solution [c (HCl) = 0.1 mol/L] and add water to dilute 10
times.
Tashiro indicator: dissolve 0.2 g of methyl red and 0.1 g of methylene blue in 100 mL of
methanol (with a volume fraction of 95%).
5.4.2.2 Test procedures
Accurately measure-take 20 mL of the test solution and place it in a 100 mL ground-mouth
sodium hydroxide standard titration solution [c (NaOH) = 0.01 mol/L] to titrate it; if it turns
green, use the hydrochloric acid standard titration solution [c (HCl) = 0.01 mol/L] to titrate it,
until it turns gray. Take the volume (in mL) of the consumed sodium hydroxide standard
titration solution [c (NaOH) = 0.01 mol/L] or hydrochloric acid standard titration solution [c
(HCl) = 0.01 mol/L] as the test result.
5.4.3 Method 3
5.4.3.1 Solution preparation
Sodium hydroxide standard titration solution [c (NaOH) = 0.1 mol/L]: same as 5.4.2.1.
Sodium hydroxide standard titration solution [c (NaOH) = 0.01 mol/L]: same as 5.4.2.1.
Hydrochloric acid standard titration solution [c (HCl) = 0.01 mol/L]: same as 5.4.2.1.
Phenolphthalein indicating solution (10 g/L): weigh-take 1 g of phenolphthalein, dissolve it in
ethanol (with a volume fraction of 95%) and dilute to 100 mL.
Methyl red indicating solution (1 g/L): weigh-take 0.1 g of methyl red, dissolve it in ethanol
(with a volume fraction of 95%) and dilute to 100 mL.
5.4.3.2 Test procedures
Add 2 drops of the phenolphthalein indicating solution to 10 mL of test solution, and the
solution shall not turn red. Add 0.4 mL of the sodium hydroxide standard titration solution [c
(NaOH) = 0.01 mol/L], and the solution shall turn red. Add 0.8 mL of the hydrochloric acid
store it in the refrigerator. Before use, take 5 mL of the mixed solution [composed of 15 mL of
sodium hydroxide (1 mol/L), 5 mL of water and 20 mL of glycerin], add 1 mL of the above-
mentioned thioacetamide solution; place it on a water bath to heat for 20 s, cool it down and
immediately use it.
Lead standard stock solution (0.1 mg/mL): weigh-take 0.160 g of lead nitrate, use 10 mL of
nitric acid solution (1 + 9) to dissolve it, then, transfer it into a 1,000 mL volumetric flask and
use water to dilute to the scale.
Lead standard solution: before use, accurately measure-take the lead standard stock solution
and dilute it to the required concentration.
Accurately measure-take 25 mL of the test solution in a 25 mL Nessler colorimetric tube; take
another 25 mL Nessler colorimetric tube and add 25 mL of the lead standard solution.
Respectively add 2 mL of acetate buffer solution (pH 3.5) to the above-mentioned two
colorimetric tubes, then, respectively add 2 mL of thioacetamide test solution, let it stand for 2
min. Place it on a white background and observe from above; compare the color shades.
If the test solution develops color, a small amount of dilute caramel solution or other non-
interfering colored solutions can be added to the standard control solution, so as to make it
consistent with the color of the test solution. Then, respectively add 2 mL of thioacetamide test
solution to the test solution and the standard control solution; shake it well and let it stand for
Alternatively, take 10 mL of the test solution, then, the amount of lead standard solution added
is 10 mL.
5.6.2 Method 2
5.6.2.1 Principle
In an alkaline solution, heavy metals, such as: lead, chromium, copper and zinc, can react with
sodium sulfide to generate insoluble colored sulfides. Take lead as a representative to prepare
a standard solution for colorimetric comparison and determine the total content of the heavy
metals.
5.6.2.2 Solution preparation
dissolve it to 100 mL. Thus, the solution is obtained.
Sodium sulfide test solution (100 g/L): before use, weigh 1 g of sodium sulfide and add water
to dissolve it to 10 mL. Thus, the solution is obtained.
Lead standard stock solution (0.1 mg/mL): same as 5.6.1.2.
Lead standard solution: same as 5.6.1.2.
5.6.2.3 Test procedures
Accurately measure-take 25 mL of the test solution in a 25 mL Nessler colorimetric tube; take
another 25 mL Nessler colorimetric tube and add 25 mL of the lead standard solution.
Respectively add 5 mL of the sodium hydroxide test solution to the above-mentioned two
it well. Place it on a white background and observe from above; compare the color shades.
5.7 UV Absorbance
Take the test solution, if necessary, use a 0.45 m microporous filter membrane to filter it.
Within 5 h, use a 1 cm cuvette with the blank control solution as a reference. Within the
specified wavelength range, determine the absorbance.
5.8 Ammonium
5.8.1 Principle
Ammonium ions can react with Nessler reagent in alkaline solution to generate a yellow
substance. Through colorimetric comparison with the standard control solution, determine its
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