活性炭碘吸附值的检测方法及要点

1、欢迎共阅活性炭碘吸附值的检测方法及要点原理一定量的试样与碘液充分振荡吸附后，经过滤，取滤液，用0.1mol/L硫代硫酸钠滴定滤液中残留的碘量。以剩余碘浓度0.02mol/L时每克炭吸附的碘量（以毫克计）定为碘值。仪器天平，感量0.1mg;I1电热恒温箱，115±5C;.一、.«I11III:搅拌式粉碎机；.?.I,.、j,二1八III振荡器，频率240275次/min;标准筛，筛孔71微米（250目，筛孔66微米）。试齐I1） 1mol/L碘标准溶液（GB601）浓度控制0.1±0.002mol/L,用硫代硫酸钠比c"!1较法标定。2） 0.1mol/L

2、硫代硫酸钠标准溶液（GB601）3） 0.5g/100mL淀粉指示剂：称0.5g可溶性淀粉，加水10mL,在搅拌下加人90mL沸水中，再微沸2min,冷却后取上清液使用，此溶液当天配制。4） （1+9鹿酸溶液。样品预处理1）除湿：对于湿活性炭，用150士5c干燥1小时再粉碎；2）粉碎：取1015g样品粉碎1min（粉碎时用毛巾或塑料袋罩住粉碎机，3min后飞扬粉尘较少时再开盖）；3）过筛：用250目标准筛，筛粉碎的样品，充分摇动；4）干燥：取510产71微米的粉碎样品于干燥称量皿中，于150±5C电热恒温箱中干燥至恒重（一般3h足够），取出放干燥器中冷却至室温备用。检测步骤1）用减量

3、法称取经粉碎至w71微米且干燥的试样约0.5g例准至0.4mg）于干燥的250mL碘量瓶中，记录称取的试样量；IrI_2）准确加入盐酸10.0mL,轻微摇动，使试样湿润，放在电炉上加热至沸，提离电炉，保持微沸30±2S,放入自来水浴中冷却至室温；3）力口0.1mol/L的碘标准溶液50.0mL,塞好瓶盖，立即在振荡机上以240275ItII，“ll./,.1/次/min的振频振荡15min;、i/八jI-7，.了!JiI4）用直径15cm的单层快速滤纸迅速过滤，用玻璃片盖住过滤漏斗，前1075mL弃去不要，收集后面的滤液；5）吸取10.0mL滤液放人已加100ML蒸储水的碘量瓶中，用

4、0.1硫代硫酸钠标准溶液滴定，在溶液呈淡黄色时，加2mL淀粉指示剂，继续滴定至溶液变成无色，记录消耗的硫代硫酸钠体积（mL）。结果计算1）计算剩余滤液浓度=C2*V2/102）据剩余浓度查附表得出校正系数D3）计算碘值，mg/g5（10G-1.2（GV2）*127A=*D式中:A试样的碘吸附值，mg/gCi碘液浓度，mol/LC2硫代硫酸钠标准溶液浓度，mol/LV2硫代硫酸钠溶液消耗量，mLM试样质量，g127碘（1/212）摩尔质量，g/molD一校正系数。U,I13精确度:碘值在6001450mg/g时，两个平行样之差w5.6%。检测要点1）因为活性炭颗粒的大小、与碘振摇的时间、频率对活

5、性炭吸附碘的能力有ItIIbI;7/影响。严格选用标准筛和振摇时间、频率。要求活性炭孔径w71微米时，可选f-«.''»I,”"用220目或250目的标准筛；2）样品应干燥。因为活性炭吸水能力极强，在目测正常情况下，水分可高达X.120%严重影响称量的准确性；3）用减量法称量活性炭。因为活性炭能快速吸水，暴露时间长会影响称量的准确性；4）因碘易挥发，移液管加碘液时沿碘量瓶下壁放出，选用配套的碘量瓶，在振摇时密封好，减少碘的损失；5）滤纸吸附碘，特别是初滤的10mL,可达7.7%,后面的滤液碘损失率逐渐减少至1.8%,故选用快速滤纸，初滤的1015m

6、L滤液不用。6）据试样碘值不同，调整试样称量范围，控制滴定量在0.83.3mL确保剩余滤液浓度在校正因子表内，查得到校正因子。碘值越低，称量越多。附表1碘值试验的校正因子D剩余浓度0.00000.000I；0.00020.00030.00040.00050.00060.000710.00080.00090.00801.16251.16131.1601.15751.15501.15331.15151.150011.14751.14630.00901.14381.14251.14001.13751.13631.13501.13251.1300(1.12881.12750.01001.12501.1

7、2381.12251.12131.12001.11751.11631.11501.11381.11130.01001.11001.10881.10751.10631.10381.10251.10001.0988|1.09751.09630.01201.09501.09381.09251.09001.08881.08751.08631.08501.08381.08250.01301.08001.07881.07751.07631.07501.07381.07251.0713.1.07001.06880.01401.06751.06631.06501.06251.06131.06001.05831

8、.057511.05631.05500.01501.05381.05251.05131.05001.04881.04751.04631.04501.04381.04250.01601.04131.04001.03881.03751.03751.03631.03501.0333.1.03251.03130.01701.03001.02881.02751.02631.02501.02451.02381.02251.02081.02000.01801.02001.01881.01751.01631.01501.01441.01381.01251.01251.01130.01901.01001.008

9、81.00751.00751.00631.00501.00501.0038.1.00251.00250.02001.00131.00001.00000.99880.99750.99750.99630.995010.99500.99380.02100.99380.99250.99250.99130.99000.99000.98880.98750.98750.98630.02200.98630.98500.98500.98380.98250.98250.98130.9813.0.98000.97880.02300.97880.97750.97750.97630.97630.97500.97500.

10、973810.97380.97250.02400.97250.97080.97000.97000.96880.96880.96750.96750.96630.96630.02500.96500.96500.96380.96380.96250.96250.96130.9613.0.96060.96000.02600.96000.95880.95880.95750.95750.95630.95630.950010.95500.95380.02700.95380.9525.0.95250.95190.95130.95130.95060.950010.95000.94880.02800.94880.94750.94750.94630.94630.94630.94500.94500.94380.94380.02900.94250.94250.84250.84130.94130.94000.94000.939410.93880.93880.03000.93750.93750.93750.93630.93630.93630.93630.9350,0.93500.93460.03