GB-T1272-1988 化学试剂 碘化钾

中华人民共和国国家标准

UDC54.41:661

1272一88

剂钾

试

化

学

化碘

Chemicalreagent

Potassiumiodide

GB1272-77

GB储

本标准参照采用国际标准ISO6353/2-1983《化学分析试剂—第2部分:规格—第一批》中

R25“碘化钾”。

本试剂为白色结晶，易溶于水，可溶于乙醇、丙酮。在潮湿空气中微具潮解性，久置会析出游离

碘而呈黄色。

分子式KI

分子量:166.00(按1985年国际原子量)

1主题内容与适用范围

本标准规定了化学试剂碘化钾的技术要求、试验方法、检验规则和包装及标志。

本标准适用于化学试剂碘化钾的检验。

2引用标准

GB601化学试剂滴定分析(容量分析)用标准溶液的制备

GB602化学试剂杂质测定用标准溶液的制备

GB603化学试剂试验方法中所用制剂及制品的制备

GB619化学试剂采样及验收规则

GB6682实验室用水规格

GB9723化学试剂火焰原子吸收光谱法通则

HC:3-119化学试剂包装及标志

3技术要求

3.1碘化钾(KI)含量不少于:

优级纯··································································⋯⋯99.5%;

分析纯·······························································，.·⋯⋯98.5%;

化学纯···············。··················································⋯⋯98.0写。

3.2pH(50g/L溶液，25}C):6.0-8-0.

3.3杂质最高含量(指标以百分含量计)见下表。

中华人民共和国化学工业部1988一06一20批准

1989一04一01实施

GB1272一88

分析纯化学纯

合格合格

O5

0白几5

000

Oq乙

1七曰n﹄

000

0.010

0.002

005002002

名称

澄清度试验

水不洛物

碘酸盐及碘(以1(计)

氯化物及澳化物(以('I计)

硫酸盐(5())

磷酸盐(PO)

总氮量(N)

钠(Nz)

镁(Mg)

钙((、‘)

铁(P曰

砷〔八咬)

钡Ud动

重金属(以P卜计)

还原性物质

优级纯

合格

0.005

0.0003

0.01

0.002

0.001

0.001

〔}，05

0.001

0.001

0.0001

0.000ol

0.001

0.0002

合格

0.10

厂乃八︺

尸JSC‘城1‘

0000000000

氏氏住一住住

犷了

八JCU民﹄

八乙宁000︺0

OC︶00曰0

OOU0llO

合格

4试验方法

4.1碘化钾(KI)含量测定

称取。.Sg样品，称准至。.0001g.溶于100mL水中，加10MI乙酸溶液((50o)及3滴曙红钠盐指示

液(Sg/l)，用硝酸银标准溶液Cc(AgNOO=0.1mol/1_D避光滴定至沉淀呈红色。

碘化钾含量按下式计算:

x-I一.c鲤丝0X100

式中:X一碘化钾之百分含量，%;

V硝酸银标准溶液之用量.ml;

硝酸银标准溶液之物质的量浓度.mol/L;

m样品质量，9;

0.166。一每毫摩尔KI相当之克数。

4.2pH

称取5g样品，称准至。.olg,溶于looml无二氧化碳的水中，在25'C时，用酸度计测定，pH值应在

6.0-8.。之间

4.3杂质测定

样品须称准至。·()]9。

4.3.1澄清度试验

称取zog样品溶于looms，水中，其浊度不得大于澄清度标准:

优级纯·······································································⋯⋯z号、

分析纯································，·····································⋯⋯3号;

GB1272一88

化学纯·······································································⋯⋯5号

4.3.2水不溶物

称取50g样品，溶于150-1沸水中·冷却至室温，用已在105士2℃恒重的4号玻璃滤祸过滤，用热

水洗涤滤渣至洗液无碘离子反应，于105士2C的电烘箱中干燥至恒重。滤渣质量不得大于:

优级纯·，·，·································································⋯⋯2.5mg;

分析纯·····································································⋯⋯5.Omg;

化学纯····················，·，，··········································⋯⋯10.Omg

4.3.3碘酸盐及碘

称取3g样品，溶于60m工、水中，优级纯取40m工一(分析纯取6mL，化学纯取2.5mL),稀释至50ml，

加3m1硫酸标准、液〔(合It2S())一。·1-01/1〕，加5m，一淀粉指示液(IOg/L)，在los内溶液不得呈现

蓝色或紫色

4.3.4氯化物及浪化物

称取1g样品，溶于100-l一水中，加lml,30%过氧化氢、1m1_磷酸，煮沸至溶液无色，冷却。加

0.5ml,300,过氧化氢.加热至过氧化氢分解完全，冷却，稀释至100mL。取lOmL，加lml.硝酸溶液

(25%)及lml硝酸银溶液(17g/[)，稀释至25ml，摇匀，放置lOmin。所呈浊度不得大于标准。

标准是取下列数量的氯化物杂质标准溶液:

优级纯·······························································⋯⋯。.olmgcl;

分析纯······························································⋯⋯。.02mgCl;

化学纯·······························································⋯⋯0.05mgCl

稀释至loml，与样品溶液同时同样处理。

4.3.5硫酸盐

称取。.5g样品，溶于loml水中，加。.5mL盐酸溶液(200),

将。.25mI硫酸钾乙醇溶液与lml_氯化钡溶液(250g/l)混合(晶种液)，准确放置lmin，加人上述

已酸化的样品溶液，稀释至25mI，摇匀，放置5min。所呈浊度不得大于标准。

标准是取下列数量的硫酸盐杂质标准溶液:

优级纯·································................................。.OlomgSO,;

分析纯···························································⋯⋯。.025mgSO,;

化学纯····························································⋯⋯。.050mgSO,.

与样品同时同样处理

4.3.6磷酸盐

称取2g样品，溶于IOml水中，加2mL硝酸，蒸发至干，冷却。再重复操作一次。残渣溶于8mL水

中，加2滴饱和2,4一二硝基酚指示液，滴加硝酸溶液(13%)至溶液黄色消失，稀释至lomL,置于分液漏

斗中，加lOmL硝酸溶液(1300)，加2ml钥酸钱溶液(100g/L)，摇匀，放置20min。加loml乙酸丁醋.萃

取，静置分层，弃去水相。有机相用盐酸溶液((5%)洗涤两次，每次5mL，弃去水相。在有机相中加入

0.2ml氯化亚锡一抗坏血酸溶液，轻轻摇动，静置分层，弃去水相于有机相中加人1mL无水乙醇，混匀

所呈蓝色不得深于标准。

标准是取卜列数量的磷酸盐杂质标准溶液:

优级纯·······························································⋯⋯。.02mgPO,;

分析纯·······························································⋯⋯。.04mgPO,

稀释至8ml，与同体积样品溶液同时同样处理。

4.17总氮量

称取2g样品，置于凯氏仪中，加140ml水溶解，加5mL氢氧化钠溶液(320g/L),1.0g定氮合金，

GB1272一88

静置1h。加热蒸馏出75mI，用盛有5mL硫酸溶液(0.500)的100mL比色管接收，加3m1氢氧化钠溶液

(320g/L),2mL纳氏试剂，稀释至100mL，摇匀。所呈黄色不得深于标准。

标准是取下列数量的氮杂质标准溶液:

优级纯·....................................................................。02mgN;

分析纯·······························································⋯⋯。.04mgN;

化学纯·······························································⋯⋯0.04mgN,

与样品同时同样处理。

4.3.8钠

按火焰原子吸收光谱法测定。

4.3.8.1仪器条件

光源:钠空心阴极灯;

波长:589.Onm;

火焰:乙炔一空气。

4.3.8.2测定方法

称取。.5g样品，溶于水，稀释至100mL。取4mL，共四份。按GB9723第6.2.2条之规定测定

4.3.9镁

按火焰原子吸收光谱法测定。

4.3.9.1仪器条件

光源:镁空心阴极灯;

波长:285.2nm;

火焰:乙炔一空气。

4.3.92测定方法

称取5g样品，溶于水，稀释至l00mL，取lOmL，共四份。按GB9723第6.2.2条之规定测定。

4.3-10钙

称取。5g样品，溶于25mL水中。取lOmL，加lOmL95%乙醉、0.SmL混合碱及1mL乙二醛缩双

邻氨基酚乙醇溶液((2g/L)，摇匀，放置5min担5mL三氛甲烷萃取(温度不超过30C)，立即比色。有机

层所呈红色不得深于标准。

标准是取下列数量的钙杂质标准溶液:

优级纯·....................................................................0.002mgCa;

分析纯·····························································⋯⋯。.004mgCa;

化学纯·····························································⋯⋯0.O1OmgCa,

稀释至lOmL，与同体积样品溶液同时同样处理。

4.3.11铁

称取2g样品，溶于15mL水中，用盐酸溶液(15写)调节溶液的pH值至2，加1mL抗坏血酸溶液

(20g/L),5ml乙酸一乙酸钠缓冲溶液(pH--4.5)及1mLl,10-菲w琳溶液(2g/L),稀释至25mL,摇匀，

放置15min。所呈红色不得深于标准。

标准是取下列数量的铁杂质标准溶液:

优级纯················································。···········⋯⋯0.002mgFe;

分析纯······························································⋯⋯。.006mgFe;

化学纯····························································⋯⋯。.010mgFe,

与样品同时同样处理。

4.3-12砷

称取log样品，置于定砷瓶中，溶于30mL水中，加20mL氯化亚锡盐酸溶液、5mL碘化钾溶液

GB1272一88

(lsog/L)及1mL硫酸铜溶液(20g/L),摇匀，于暗处放置35min。加5.Og无砷锌，立即将塞有乙酸铅棉

花及盛有5mL吸收液(二乙基二硫代氨基甲酸银一三乙基胺三抓甲烷溶液)的吸收管装在定砷瓶上，反

应30min(避免阳光直射)。取下吸收管(勿使吸收液倒吸)，用三抓甲烷将吸收液补充至5mL，摇匀。所呈

紫红色不得深于标准。

标准是取下列数量的砷杂质标准溶液:

优级纯·················，·············································⋯⋯。.OO1mgAs;

分析纯····..................................······················⋯⋯。.002mgAs,

与样品同时同样处理。

4.3.13钡

称取2g样品(化学纯称取lg样品)，溶于20mL水中，加5mL95%乙醇、30mg抗坏血酸、1mL硫酸

溶液(20%)，摇匀，放置lOmin。所呈浊度不得大于标准。

标准是取下列数量的钡杂质标准溶液:

优级纯··························································⋯⋯。.02mgBa;

分析纯，··，，，············································，·，········，..一0.04mgBa;

化学纯·.........................·········4·44·········..·········⋯⋯0.04mgBa,

与样品同时同样处理。

4.3.14重金属

称取log样品，加lOmL硫酸溶液(1-1-1)，缓缓加热至硫酸蒸气逸尽，冷却。残渣溶于20mL水中。

取15mL，