活性炭碘吸附值的檢測(cè)方法及要點(diǎn)VIP

1、歡迎共閱活性炭碘吸附值的檢測(cè)方法及要點(diǎn)原理一定量的試樣與碘液充分振蕩吸附后，經(jīng)過濾，取濾液，用0.1mol/L硫代硫酸鈉滴定濾液中殘留的碘量。以剩余碘濃度0.02mol/L時(shí)每克炭吸附的碘量（以毫克計(jì)）定為碘值。儀器天平，感量0.1mg;I1電熱恒溫箱，115±5C;.一、.«I11III:攪拌式粉碎機(jī)；.?.I,.、j,二1八III振蕩器，頻率240275次/min;標(biāo)準(zhǔn)篩，篩孔71微米（250目，篩孔66微米）。試齊I1） 1mol/L碘標(biāo)準(zhǔn)溶液（GB601）濃度控制0.1±0.002mol/L,用硫代硫酸鈉比c"!1較法標(biāo)定。2） 0.1mol/L

2、硫代硫酸鈉標(biāo)準(zhǔn)溶液（GB601）3） 0.5g/100mL淀粉指示劑：稱0.5g可溶性淀粉，加水10mL,在攪拌下加人90mL沸水中，再微沸2min,冷卻后取上清液使用，此溶液當(dāng)天配制。4） （1+9鹿酸溶液。樣品預(yù)處理1）除濕：對(duì)于濕活性炭，用150士5c干燥1小時(shí)再粉碎；2）粉碎：取1015g樣品粉碎1min（粉碎時(shí)用毛巾或塑料袋罩住粉碎機(jī)，3min后飛揚(yáng)粉塵較少時(shí)再開蓋）；3）過篩：用250目標(biāo)準(zhǔn)篩，篩粉碎的樣品，充分搖動(dòng)；4）干燥：取510產(chǎn)71微米的粉碎樣品于干燥稱量皿中，于150±5C電熱恒溫箱中干燥至恒重（一般3h足夠），取出放干燥器中冷卻至室溫備用。檢測(cè)步驟1）用減量

3、法稱取經(jīng)粉碎至w71微米且干燥的試樣約0.5g例準(zhǔn)至0.4mg）于干燥的250mL碘量瓶中，記錄稱取的試樣量；IrI_2）準(zhǔn)確加入鹽酸10.0mL,輕微搖動(dòng)，使試樣濕潤(rùn)，放在電爐上加熱至沸，提離電爐，保持微沸30±2S,放入自來水浴中冷卻至室溫；3）力口0.1mol/L的碘標(biāo)準(zhǔn)溶液50.0mL,塞好瓶蓋，立即在振蕩機(jī)上以240275ItII，“l(fā)l./,.1/次/min的振頻振蕩15min;、i/八jI-7，.了!JiI4）用直徑15cm的單層快速濾紙迅速過濾，用玻璃片蓋住過濾漏斗，前1075mL棄去不要，收集后面的濾液；5）吸取10.0mL濾液放人已加100ML蒸儲(chǔ)水的碘量瓶中，用

4、0.1硫代硫酸鈉標(biāo)準(zhǔn)溶液滴定，在溶液呈淡黃色時(shí)，加2mL淀粉指示劑，繼續(xù)滴定至溶液變成無色，記錄消耗的硫代硫酸鈉體積（mL）。結(jié)果計(jì)算1）計(jì)算剩余濾液濃度=C2*V2/102）據(jù)剩余濃度查附表得出校正系數(shù)D3）計(jì)算碘值，mg/g5（10G-1.2（GV2）*127A=*D式中:A試樣的碘吸附值，mg/gCi碘液濃度，mol/LC2硫代硫酸鈉標(biāo)準(zhǔn)溶液濃度，mol/LV2硫代硫酸鈉溶液消耗量，mLM試樣質(zhì)量，g127碘（1/212）摩爾質(zhì)量，g/molD一校正系數(shù)。U,I13精確度:碘值在6001450mg/g時(shí)，兩個(gè)平行樣之差w5.6%。檢測(cè)要點(diǎn)1）因?yàn)榛钚蕴款w粒的大小、與碘振搖的時(shí)間、頻率對(duì)活

5、性炭吸附碘的能力有ItIIbI;7/影響。嚴(yán)格選用標(biāo)準(zhǔn)篩和振搖時(shí)間、頻率。要求活性炭孔徑w71微米時(shí)，可選f-«.''»I,”"用220目或250目的標(biāo)準(zhǔn)篩；2）樣品應(yīng)干燥。因?yàn)榛钚蕴课芰O強(qiáng)，在目測(cè)正常情況下，水分可高達(dá)X.120%嚴(yán)重影響稱量的準(zhǔn)確性；3）用減量法稱量活性炭。因?yàn)榛钚蕴磕芸焖傥┞稌r(shí)間長(zhǎng)會(huì)影響稱量的準(zhǔn)確性；4）因碘易揮發(fā)，移液管加碘液時(shí)沿碘量瓶下壁放出，選用配套的碘量瓶，在振搖時(shí)密封好，減少碘的損失；5）濾紙吸附碘，特別是初濾的10mL,可達(dá)7.7%,后面的濾液碘損失率逐漸減少至1.8%,故選用快速濾紙，初濾的1015m

6、L濾液不用。6）據(jù)試樣碘值不同，調(diào)整試樣稱量范圍，控制滴定量在0.83.3mL確保剩余濾液濃度在校正因子表內(nèi)，查得到校正因子。碘值越低，稱量越多。附表1碘值試驗(yàn)的校正因子D剩余濃度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