選擇、購買標準物質應考慮哪些要素?
(1)特性量的種類及定值方法:mouxiebiaozhunwuzhikenengzhishiyongmouyitedingfangfahuozhuanshulingyudeyingyong,mouxiebiaozhunwuzhidezhiyouteshuguiding,ruhanjiejingshuidezhi,yingduizhengshuzhonggaileishuomingjiayizhuyi,fangzhiwuxuanwuyong;
(2)特性量水平:標準物質的特性量水平應與日常測量樣品的水平匹配;
(3)可接受的不確定度水平:標準物質特性量的相關不確定度水平應與日常測量中的精密度和正確度限度要求匹配;
(4)基體及可能的幹擾:標準物質用於開展方法確認、質量控製以及一些基體效應較為嚴重的測量方法的校準時,基體應與日常測量樣品基體盡可能接近;
(5)形式:biaozhunwuzhikezhibeichengbutongdexingshi,rudongganyubingdongyangpin,zhibeifangshidebutongkenenghuidaozhixiangtongtexingzaibiaozhunwuzhiyuzhenshiyangpinzhongdexingweichayi,congerchanshenghuhuanxingwenti,xuangouqianyingchongfentiaoyan;
(6)最小取樣量:隻(zhi)要(yao)標(biao)準(zhun)物(wu)質(zhi)證(zheng)書(shu)中(zhong)規(gui)定(ding)了(le)最(zui)小(xiao)取(qu)樣(yang)量(liang),用(yong)於(yu)測(ce)量(liang)的(de)取(qu)樣(yang)量(liang)應(ying)不(bu)小(xiao)於(yu)該(gai)最(zui)小(xiao)取(qu)樣(yang)量(liang),因(yin)此(ci)選(xuan)購(gou)時(shi)應(ying)考(kao)慮(lv)最(zui)小(xiao)取(qu)樣(yang)量(liang)是(shi)否(fou)能(neng)滿(man)足(zu)測(ce)量(liang)方(fang)法(fa)要(yao)求(qiu);
(7)用量:標準物質的購買用量應足以滿足整個實驗計劃中的應用,包括根據需要考慮的備樣;
(8)穩定性:選購前應確認所購買批次標準物質的有效期限,避免使用時發生過期的情況。
購買的有證標準物質如何驗證?
對於購買到的標準物質,在收到後應首先對照證書確認標準物質的運輸條件是否符合要求,然後核對品種、數量等是否與購買要求一致,包裝、外觀是否正常,標識是否清晰、完整;youwuzhengshu,shifouzaizhengshushengmingdeyouxiaoqineideng。heduiwanbihou,lijianzhaozhengshuzhongguidingdebaocuntiaojianjinxingbaocun。ruyouwenti,yingjishiyuyanzhihuofashoudanweilianxi。
標準品常見問題解答:
1.有證書(certificate)的標準物質就是有證標準物質麼(CRM)嗎?
回答這個問題,首先要理解“有證標準物質”(Certified Reference Material)的含義。有證標準物質是指“附有由權威機構發布的文件,提供使用有效程序獲得的具有不確定度和溯源性的一個或多個特性值的標準物質”。因此,有證書的標準物質不一定就是有證標準物質。
有證標準物質應具有以下基本特征:
(1)溯源性和不確定度聲明;
(2)標準物質的製備、定值及認定符合由ISO指南34和指南35給出的有效程序,我國已將上述指南等效轉化為JJF1342《標準物質研製(生產)機構通用要求》和JJF1343《標準物質定值的通用原則及統計學原理》,成為國家標準物質的評審、發布的技術依據。
2.有證標準物質和其它標準物質在使用上有什麼區別?
首先應明確,隻有有證標準物質提供的認定值或標準值才能夠用於校準、為wei其qi他ta物wu質zhi賦fu值zhi以yi及ji測ce量liang正zheng確que度du確que認ren,並bing通tong過guo其qi使shi用yong來lai聲sheng明ming測ce量liang結jie果guo的de計ji量liang學xue溯su源yuan性xing。在zai我wo們men的de日ri常chang測ce量liang中zhong還hai會hui使shi用yong其qi它ta類lei型xing的de標biao準zhun物wu質zhi,它ta們men主zhu要yao用yong於yu開kai展zhan測ce量liang質zhi量liang控kong製zhi、測量精密度確認等。
有(you)時(shi),在(zai)缺(que)少(shao)有(you)證(zheng)標(biao)準(zhun)物(wu)質(zhi)的(de)情(qing)況(kuang)也(ye)不(bu)得(de)不(bu)使(shi)用(yong)這(zhe)些(xie)標(biao)準(zhun)物(wu)質(zhi)來(lai)開(kai)展(zhan)校(xiao)準(zhun)等(deng)活(huo)動(dong),但(dan)是(shi)應(ying)進(jin)一(yi)步(bu)評(ping)估(gu)這(zhe)些(xie)標(biao)準(zhun)物(wu)質(zhi)是(shi)否(fou)符(fu)合(he)有(you)證(zheng)標(biao)準(zhun)物(wu)質(zhi)的(de)特(te)征(zheng),或(huo)溯(su)源(yuan)性(xing)和(he)量(liang)值(zhi)不(bu)確(que)定(ding)度(du)水(shui)平(ping)能(neng)夠(gou)充(chong)分(fen)滿(man)足(zu)測(ce)量(liang)結(jie)果(guo)溯(su)源(yuan)性(xing)和(he)準(zhun)確(que)度(du)要(yao)求(qiu)。
有證標準物質的參考值或信息值
有you證zheng標biao準zhun物wu質zhi的de證zheng書shu中zhong,有you時shi會hui提ti供gong一yi些xie額e外wai的de參can考kao值zhi或huo信xin息xi值zhi,這zhe些xie值zhi通tong常chang缺que少shao明ming確que的de計ji量liang學xue溯su源yuan性xing,缺que少shao不bu確que定ding度du信xin息xi或huo不bu確que定ding度du評ping估gu不bu全quan麵mian。因yin此ci它ta們men的de主zhu要yao用yong途tu是shi幫bang助zhu用yong戶hu了le解jie標biao準zhun物wu質zhi基ji體ti組zu成cheng,判pan斷duan標biao準zhun物wu質zhi的de適shi用yong性xing,或huo視shi可ke靠kao程cheng度du用yong於yu開kai展zhan測ce量liang質zhi量liang控kong製zhi。
3.標準物質一定要在有效期內使用嗎?
標(biao)準(zhun)物(wu)質(zhi)的(de)有(you)效(xiao)期(qi)是(shi)研(yan)製(zhi)單(dan)位(wei)根(gen)據(ju)穩(wen)定(ding)性(xing)研(yan)究(jiu)數(shu)據(ju),為(wei)了(le)確(que)保(bao)標(biao)準(zhun)物(wu)質(zhi)量(liang)值(zhi)及(ji)不(bu)確(que)定(ding)度(du)的(de)可(ke)靠(kao)性(xing)而(er)確(que)定(ding)的(de),因(yin)此(ci)務(wu)必(bi)在(zai)有(you)效(xiao)期(qi)內(nei)使(shi)用(yong)。到(dao)期(qi)後(hou)未(wei)使(shi)用(yong)的(de)標(biao)準(zhun)物(wu)質(zhi)也(ye)許(xu)仍(reng)舊(jiu)穩(wen)定(ding),對(dui)於(yu)一(yi)些(xie)批(pi)量(liang)較(jiao)大(da)、穩定性周期較長(如五年以上)的(de)標(biao)準(zhun)物(wu)質(zhi),研(yan)製(zhi)單(dan)位(wei)有(you)時(shi)會(hui)提(ti)供(gong)延(yan)長(chang)有(you)效(xiao)期(qi)的(de)服(fu)務(wu),但(dan)是(shi)在(zai)標(biao)準(zhun)物(wu)質(zhi)的(de)穩(wen)定(ding)性(xing)無(wu)法(fa)得(de)到(dao)研(yan)製(zhi)單(dan)位(wei)保(bao)證(zheng)的(de)情(qing)況(kuang)下(xia),用(yong)戶(hu)如(ru)果(guo)繼(ji)續(xu)使(shi)用(yong)該(gai)標(biao)準(zhun)物(wu)質(zhi),需(xu)自(zi)行(xing)承(cheng)擔(dan)責(ze)任(ren)。
4.為什麼一定要按照證書中規定的條件使用和保存標準物質?
biaozhunwuzhizhengshuzhongguidingdeshiyonghebaocuntiaojianshiquebaodebiyaotiaojian。biaozhunwuzhidebaocuntiaojianshizaiwendingxingyanjiuzhongquedingde,erbiaozhunwuzhideshiyongtiaojian,ruwendu、配製方法、幹燥方法、水分校正方法、混hun勻yun方fang法fa等deng,則ze是shi標biao準zhun物wu質zhi定ding值zhi過guo程cheng嚴yan格ge確que定ding和he遵zun守shou的de,不bu按an照zhao規gui定ding使shi用yong和he保bao存cun會hui導dao致zhi標biao準zhun物wu質zhi的de量liang值zhi不bu再zai有you效xiao,測ce量liang結jie果guo與yu標biao準zhun值zhi相xiang比bi較jiao出chu現xian偏pian差cha。
5.打開後的標準物質如何保存?
標準物質證書中有時會規定“一次性使用”,zhexiebiaozhunwuzhiyibanbuwendinghuojuyoujiaogaodeliangzhizhunquedu,ruanbupingfenzhuangdeguojiayijirongyebiaozhunwuzhi,zaidakaibaozhuanghouliangzhiyifashengchaochubuquedingdufanweidebianhua,yinganzhaoyaoqiujinkuaiyiqu,bunengliucunhoufanfushiyong。keyicixingzhibeichengzhongjianbiaozhunchubeirongyebaocun、使用。
對於可多次使用的有證標準物質,確保標準物質包裝單元開封後的恰當保存和包裝、證書的完整性非常重要。某些情況下,有必要根據證書要求,對剩餘的物質進行重新密封包裝。取樣時應采取防止沾汙的措施。
6.標準物質的最小取樣量有什麼意義?
biaozhunwuzhidezuixiaoquyangliangshizaijunyunxingyanjiuzhongguidingde。shiyongbiaozhunwuzhishideshijiquyangliangyingbudiyubiaozhunwuzhidezuixiaoquyangliang,dangxiaoyubiaozhunwuzhidezuixiaoquyangliangshiyongshi,zhengshuzhongshengmingdebiaozhunwuzhitexingliangzhihebuquedingdudengcanshukenenghuiyouyubiaozhunwuzhidebujunyunxingerbuzaiyouxiao。
7.標準物質的測量值一定要在不確定度之內嗎?
如(ru)果(guo)實(shi)驗(yan)室(shi)對(dui)標(biao)準(zhun)物(wu)質(zhi)的(de)測(ce)量(liang)值(zhi)超(chao)出(chu)了(le)標(biao)準(zhun)物(wu)質(zhi)特(te)性(xing)量(liang)值(zhi)的(de)不(bu)確(que)定(ding)度(du)範(fan)圍(wei),是(shi)不(bu)能(neng)直(zhi)接(jie)得(de)出(chu)測(ce)量(liang)結(jie)果(guo)存(cun)在(zai)偏(pian)差(cha)的(de)結(jie)論(lun)的(de),原(yuan)因(yin)是(shi)標(biao)準(zhun)物(wu)質(zhi)的(de)不(bu)確(que)定(ding)度(du)U標準物質僅包括了與標準物質定值、均勻性、穩定性有關的不確定度U測ce,沒mei有you涉she及ji用yong戶hu在zai實shi驗yan室shi裏li對dui標biao準zhun物wu質zhi進jin行xing測ce量liang有you關guan的de隨sui機ji不bu確que定ding度du。因yin此ci,應ying采cai取qu以yi下xia通tong用yong公gong式shi判pan斷duan標biao準zhun物wu質zhi測ce量liang值zhi與yu標biao準zhun值zhi之zhi間jian存cun在zai顯xian著zhu偏pian差cha:
S代表標準偏差,n代表重複次數,t值可根據n和置信概率水平查表得到。此外,要注意在測量條件達到穩定後使用標準物質,否則會導致錯誤的結論。
8.校準用標準物質的稀釋和使用過程中應注意什麼?
yonghugoumaidaodexiaozhunyongbiaozhunwuzhichangchangnongdujiaogao,bunengzhijieshiyong,yingzuohaozhexieguochengdezhiliangkongzhi。biaozhunwuzhixishipeizhiguochengzhongsuoshiyongderongqiyuxishijixuyaoyinqizhuyi:有些物質用玻璃瓶存儲時,容易受降解或溶出影響,這時就要使用其它材料的瓶子,如K、Na等元素溶液標準物質需采用塑料瓶保存;有些物質用塑料瓶存儲則會發生吸附或溶出,如汞在塑料瓶中可能會產生吸附現象,因此選擇玻璃瓶較為可靠。
所(suo)采(cai)用(yong)的(de)稀(xi)釋(shi)劑(ji)除(chu)了(le)應(ying)對(dui)空(kong)白(bai)進(jin)行(xing)必(bi)要(yao)的(de)控(kong)製(zhi)外(wai),不(bu)同(tong)的(de)稀(xi)釋(shi)劑(ji)其(qi)穩(wen)定(ding)效(xiao)果(guo)也(ye)不(bu)同(tong),原(yuan)則(ze)上(shang)應(ying)按(an)照(zhao)檢(jian)測(ce)標(biao)準(zhun)方(fang)法(fa)中(zhong)規(gui)定(ding)的(de)稀(xi)釋(shi)劑(ji)品(pin)種(zhong)及(ji)濃(nong)度(du)進(jin)行(xing)配(pei)製(zhi)。標(biao)準(zhun)物(wu)質(zhi)稱(cheng)量(liang)、稀釋過程中使用的計量器具,如天平、移液器、容rong量liang瓶ping等deng,應ying經jing適shi當dang的de校xiao準zhun或huo檢jian定ding確que認ren符fu合he精jing度du和he準zhun確que度du要yao求qiu,特te別bie是shi有you機ji分fen析xi中zhong使shi用yong的de微wei量liang注zhu射she器qi和he移yi液ye槍qiang的de誤wu差cha較jiao大da,應ying注zhu重zhong進jin行xing日ri常chang校xiao準zhun。
9.標準物質如何開展量值核驗?
如何在使用環節做好標準物質的量值控製常常是用戶困惑的問題。標準物質的量值控製應分以下情況製定具體的措施:
(1)duiyuyouzhengbiaozhunwuzhi,zhiyaoanzhaobiaozhunwuzhizhengshushangsuoguidingdetiaojianhefangfabaocun,bingzaiyouxiaoqineishiyong,liangzhishiyoubaozhangde,zheleibiaozhunwuzhidehezhayingjianhuaweijianzhabaozhuang、標簽及證書的完好性、有效期、保存條件等;如(ru)果(guo)是(shi)開(kai)封(feng)後(hou)可(ke)多(duo)次(ci)使(shi)用(yong)的(de)有(you)證(zheng)標(biao)準(zhun)物(wu)質(zhi),除(chu)了(le)上(shang)述(shu)核(he)查(zha)外(wai),實(shi)驗(yan)室(shi)應(ying)製(zhi)定(ding)相(xiang)應(ying)的(de)文(wen)件(jian)規(gui)範(fan)其(qi)後(hou)續(xu)使(shi)用(yong)和(he)管(guan)理(li),定(ding)期(qi)檢(jian)查(zha)其(qi)使(shi)用(yong)的(de)情(qing)況(kuang),必(bi)要(yao)時(shi)與(yu)另(ling)一(yi)未(wei)開(kai)封(feng)單(dan)元(yuan)或(huo)批(pi)次(ci)的(de)標(biao)準(zhun)物(wu)質(zhi)通(tong)過(guo)比(bi)對(dui)進(jin)行(xing)量(liang)值(zhi)核(he)驗(yan)。
(2)對dui於yu內nei部bu標biao準zhun物wu質zhi或huo實shi驗yan室shi由you有you證zheng標biao準zhun物wu質zhi製zhi備bei的de校xiao準zhun溶rong液ye等deng,由you於yu沒mei有you充chong分fen的de均jun勻yun性xing和he穩wen定ding性xing數shu據ju,嚴yan格ge的de量liang值zhi控kong製zhi是shi非fei常chang必bi要yao的de。可ke采cai取qu的de方fang式shi視shi實shi驗yan室shi的de經jing濟ji和he技ji術shu條tiao件jian靈ling活huo掌zhang握wo,如ru利li用yong質zhi量liang控kong製zhi圖tu進jin行xing趨qu勢shi檢jian查zha、通tong過guo上shang下xia批pi標biao準zhun物wu質zhi量liang值zhi比bi對dui或huo實shi驗yan室shi間jian比bi對dui驗yan證zheng量liang值zhi的de準zhun確que性xing等deng。此ci外wai核he查zha的de頻pin次ci要yao根gen據ju標biao準zhun物wu質zhi的de特te點dian製zhi定ding,穩wen定ding性xing預yu期qi良liang好hao的de標biao準zhun物wu質zhi可ke相xiang對dui放fang寬kuan核he查zha的de時shi間jian間jian隔ge。
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