环境检测试验基础.pdf

Experimental Foundation for Experimental Foundation for Experimental Foundation for Experimental Foundation for Environmental Environmental Environmental Environmental MornitoringMornitoringMornitoringMornitoring（1 1 1 1）YU Ji jinCUI Yu QianQingdao UniversityHOU Qian huiQingdao Puren InstrumentZHAO Chun huaCentre testing International Corp环境监测实验基础（1）环境监测实验基础（1）青岛大学余季金 崔育倩青岛华测赵春华青岛普仁仪器公司侯倩慧PrefaceReliable statistics showed that main reason for failed case in authentication of environmental monitoring lab,is not due to bad instrument quality,but others,for example,problems in reagents and experimental water inspection,inaccurate working standard&preparation of“blind sample”solution,etc,all can lead to incorrect analytical results.序言序言可靠的统计资料表明，在环境监测实验室认证考核中大多数的分析项目结果不合格者，主要不是因为其使用的仪器质量不够好,而是因为其他一些问题。例如，疏忽所用试剂的实际质量和实验用水达标鉴别,不够精细的标准系列配制和“盲样”分析液制备,最终就导致分析结果超差。Therefore,solid foundation and skill in analytical chemistry experiment is necessary for improving the quality of environmental monitoring,which refer to the knowledge of lab safety;labs water,reagent specification and preservation;analytical balance;weight&titration analysis;calibrations,etc.Lab safety is one of the most important issue.因此，具备扎实的分析化学实验基础知识与操作技能是提高环境监测工作质量的必备条件。该基础知识和技能包括：实验用水、试剂的规格及试剂的使用和保存、实验室安全知识实验室安全知识、分析天平及其称量方法、化学滴定法基本操作、重量分析基本操作以及量具的校正等。其中，实验室安全实验室安全是最重要的。1 Experiment water for environmental monitoring Pure water,distilled water or deionized water would be used.Redistilled water or higher specifications are for electronic anachem,HPLC,etc.Pure water is not absolutely pure,but impurity lower in certain micro-lever.1 环境监测实验用水1 环境监测实验用水分析化学实验应使用纯水，一般是蒸馏水或去离子水。有的实验要求用二次蒸馏水或更高规格的纯水（如：电分析化学、液相色谱等的实验）。纯水并非绝对不含杂质，只是杂质含量极微而已。分析化学实验用水的级别及主要技术指标，见表1。The level and technical indices are listed in following.Table 1 water level and technical index(fr.GB6682-92)name lever1 level 2 level 3PH no rule(nr)nr 5.0 7.5 Conductivity(25),mS/m,(),0.01 0.1 0.50 Combustible subs(in(O),mg/L,(),nr 0.08 0.4 Evaporites(1052),mg/L,(),nr 1.0 2.0 Absorbancy(254nm,1cm optical path),(),0.001 0.01 nr Soluble silicon(in(SiO2),mg/L,(),0.01 0.02 nr 指标名称指标名称一级一级二级二级三级三级pH值范（值范（25 C）5.0 7.5 电导率（电导率（25 C）/mSm-1（）（）0.01 0.10 0.50 可氧化物质（以（可氧化物质（以（O）计）计）/mgL-1（）0.08 0.4 蒸发残渣（蒸发残渣（105 2 C）/mgL-1 （）（）1.0 2.0吸光度（吸光度（254nm，1cm光程）（）光程）（）0.001 0.01 可溶性硅（以（可溶性硅（以（SiO2）计）计）/mg.L-1（）（）0.01 0.02 注：在一级、二级纯度的水中，难于测定真实的注：在一级、二级纯度的水中，难于测定真实的pH值，因此对其值，因此对其pH值的范围不作规定；在一级水中，难于测定其可氧化物质和蒸发残渣，故也不作规定。值的范围不作规定；在一级水中，难于测定其可氧化物质和蒸发残渣，故也不作规定。环境监测实验用水的级别及主要技术指标，如表1所示。表表1 分析化学实验室用水的级别及主要技术指标分析化学实验室用水的级别及主要技术指标（载自GB668292）1.1 Distilled water:Distilled water is made by distillation to remove non-volatile impurities.The impurities varieties and contents are different with different set.Glass distillation water may contain Na+and SiO2-,and Cu+with copper distillation.Stainless steel set is popular for better quality.1.1 蒸馏水：1.1 蒸馏水：通过蒸馏方法、除去水中非挥发性杂质而得到的纯水称为蒸馏水。同是蒸馏所得纯水，其中含有的杂质种类和含量也不同。用玻璃蒸馏器蒸馏所得的水含有Na+和SiO2-等离子；而用铜蒸馏器所制得的纯水则可能含有Cu+离子。用纯不锈钢蒸馏器，所制得的纯水质量较好。1.2 Deionized water:Using ion-exchange agent to remove cations and anions,deionized water is produced.Pls note that old deionized water may contain microorganisms and organic impurities.1.2 去离子水：1.2 去离子水：利用离子交换剂去除水中的阳离子和阴离子杂质所得的纯水，称之为离子交换水或“去离子水”。未进行处理的去离子水可能含有微生物和有机物杂质，使用时应注意。Electrodeionization（EDI）is a combination technology of ion exchange and ion electric migration for pure water.By using mixed ion exchange resins to adsorb ions in supply water,and these adsorbed ions are removed by the action of going through anion exchange membrane and cation exchange membrane respectively under DC voltage.Ion exchange resin is electric continuous renewable without traditional acid and alkali operation.电去离子（Electrodeionization）简称EDI，是离子交换技术和离子电迁移技术相结合的新的纯水制造技术。利用混合离子交换树脂吸附水中的阴离子和阳离子，同时这些被吸附的离子又在直流电压的作用下，分别透过阴与阳离子交换膜而被去除。这一过程中离子交换树脂是被电连续再生的，不需要传统费时费力的酸与碱再生过程。1.3 Pure water quality inspection The index include water resistivity,acidity,calcium&magnesium ions,chloride ion,etc.(1)The resistivity:conductivity (min range 0.02 mS/cm)(see table 1.1).(2)PH index:6 7 pH value.Test way are as follows:1.3 纯水质量的检验1.3 纯水质量的检验纯水的质量检验指标很多，分析化学实验室要对实验用水的电阻率、酸碱度、钙镁离子、氯离子的含量等进行检测。(1)电阻率：选用适合测定纯水的电导率仪电导率仪（最小量程为0.02 Scm-1）测定（见表1.1）。(2)酸碱度：要求pH值为67。检验方法如下：simple method:water 10 mL in each test-tube;1)add 2 drops of methyl red indicator,no red colour appeared.2)add 5 drops of 0.1%bromine thyme phenol blue,no blue colour observed.instrument method:with acidity meter,under atmospheric balance,water pH is at 6 7.简易法：取2支试管，各加待测水样10 ml，其中一支加入2滴甲基红指示剂应不显红色；另一支试管加5滴0.1%溴麝香草酚蓝（溴百里酚蓝）不显蓝色为合要求。仪器法：用酸度计测量与大气相平衡的纯水的pH值，在67为合格。Ca 2+Mg2+:50 ml water,add 1 ml of ammonia chloride(pH=10),a bit of chromium black T(EBT),no red showed(be pure blue!).CL-:10 ml water,add 2 drops of 1 mol/L HNO3,2 drops of 10 g/L AgNO3,no turbidity appeared.钙镁离子：取50 ml待测水样，加入pH=10的氨水-氯化铵缓冲液1 ml和少许铬黑T（EBT）指示剂，不显红色（应显纯蓝色）。氯离子：取10 ml待测水样，用2滴1 molL-1HNO3酸化，然后加入2滴10 gL-1AgNO3溶液，摇匀后不浑浊为合要求。In chemical analysis,deionized water for complex-titration,distilled water for other methods.pure water must keep without pollution.Usually they are made of polyethylene material.化学分析法中，除络合滴定必须用去离子水外，其它方法均可采用蒸馏水。分析实验用的纯水必须注意保持纯净、避免污染。通常采用以聚乙烯为材料制成的容器盛载实验用纯水。1.4 Reagent specification,use and preservation Specification&use:for accuracy of anal results,pay attention to experiment circumstances,the content and object,sensitivity and selectivity,etc,use an appropriate grade to avoid waste.Preservation:without contamination and metamorphism.1.4 常用试剂的规格及试剂的使用和保存1.4 常用试剂的规格及试剂的使用和保存分析化学实验中所用试剂的质量，直接影响分析结果的准确性，因此应根据所做试验的具体情况，如分析方法的灵敏度与选择性，分析对象的含量及对分析结果准确度的要求等，合理选择相应级别的试剂，在既能保证实验正常进行的同时，又可避免不必要的浪费。试剂应合理保存，避免沾污和变质。1.4.1 Reagent classification Thousands kinds of reagents produced,new reagents emerge with science development.No unified classification indicated.Only briefly introduce the standard reagent,general reagent and specific reagent as following:1.4.1 化学试剂的分类化学试剂产品已有数千种，而且随着科学技术和生产的发展，新的试剂种类还将不断产生，现在还没有统一的分类标准，这里只简要地介绍标准试剂、一般试剂、高纯试剂和专用试剂。(1)The standard reagentsStandard reagent,standard reference materials,is used to measure chemical amount in other materials.Its characteristic is high main contents,reliable to use.Our country stipulates that main content are from 100(+-)0.02%to 100(+-)0.05%for titration analysis.domestic standard reagents are listed in 1.4(1)(see table 1)（1）标准试剂（1）标准试剂标准试剂是用于衡量其它（欲测）物质化学量的标准物质，习惯称之为基准试剂，其特点是主体含量高，使用可靠。我国规定滴定分析第一基准和滴定分析工作基准的其主体含量分别为1000.02%和1000.05%。主要国产标准试剂的种类及用途见表1.4(1)。Table 1.4(1)Chinastandard reagent specifications&usageClass UseTitration analysis First Primary Standard;for setting value ofworking standard reagentsTitration analysis working standard reagent;for fixing value of titration analysis standard solutionTitration analysis standard solution;for determination of material content with titration method standard solution for Impurities analysis;for trace impurities analysis in instrumental and chemical analysisLevel 1 pH benchmark reagent;for setting value of pH benchmark reagents,and calibration of pH meter;PH benchmark reagent,for calibration of pH meter;表表1.4(1)主要国产标准主要国产标准试剂的规格与用途试剂的规格与用途类别主要用途类别主要用途滴定分析第一基准试剂工作基准试剂的定值滴定分析工作基准试剂滴定分析标准溶液的定值滴定分析标准溶液滴定分析法测定物质的含量杂质分析标准溶液仪器及化学分析中作为微量杂质分析的标准一级滴定分析第一基准试剂工作基准试剂的定值滴定分析工作基准试剂滴定分析标准溶液的定值滴定分析标准溶液滴定分析法测定物质的含量杂质分析标准溶液仪器及化学分析中作为微量杂质分析的标准一级pH基准试剂基准试剂pH基准试剂的定值和高精密度基准试剂的定值和高精密度pH计的校准计的校准pH基准试剂基准试剂pH计的校准（定位）热值分析试剂热值分析仪的标定气相色谱分析标准试剂气相色谱法进行定性和定量分析的标准临床分析标准溶液临床化验农药分析标准试剂农药分析有机元素分析标准试剂有机物元素分析计的校准（定位）热值分析试剂热值分析仪的标定气相色谱分析标准试剂气相色谱法进行定性和定量分析的标准临床分析标准溶液临床化验农药分析标准试剂农药分析有机元素分析标准试剂有机物元素分析Class/UseCalorific value analysis reagent;for calibration of calorific value analyzer;Standard reagent of Gas chromatographic analysis;standard in the analysis of gas chromatography(quantitative and qualitative);Clinical analysis standard solution;for clinical laboratory testing;Pesticide analysis standard reagent;for pesticide analysisOrganic element analysis standard:for organic materials analysis;级别/使用热值分析试剂;对校准热量分析仪;气相色谱分析标准试剂;气相色谱法(定量和定性的)标准;临床分析标准溶液;临床实验室测试;农药分析标准试剂;农药和农药残留分析；有机元素分析标准；有机材料分析;(2)General reagentsThe most common reagents in lab,On their impurity differences,classified as grade one,two,three,four and biochemical reagents etc.The details are listed in table 1.4.(2).（2）一般试剂一般试剂是实验室最普遍使用的试剂，其规格是以其中所含杂质的多少来划分，包括通用的一、二、三、四级试剂和生化试剂等。一般试剂的分级、标志、标签颜色和主要用途列于表1.4.（2）。Table 1.4.(2)generalchemical reagents _level specification symbol scope labeling color_1 grade pure(guarantee reagent)G R precision analysisgreen 2 analysis pure(analysis reagent)AR general analysis red3 chemical pure C P general experiment blue4 experimental reagent L R general experiment auxiliary reagent brown or other colorsBiochem reagents bio&biomedi B R biochem and medicinalcolorings experiment brown or rose _ 表表1.4.（2）一 般化学试剂的规格及选用一 般化学试剂的规格及选用_级别中文名称英文符号适用范围标签颜级别中文名称英文符号适用范围标签颜_一级优级纯（保证试剂）G R 精密分析实验绿色二级分析纯（分析试剂）A R 一般分析实验红色三级化学纯C P 一般化学实验蓝色四级实验试剂L R 一般化学实验辅助试剂棕色或其它颜色生化试剂 生化试剂 生物染色剂B R 生物化学及医用化学实验咖啡色玫瑰色一级优级纯（保证试剂）G R 精密分析实验绿色二级分析纯（分析试剂）A R 一般分析实验红色三级化学纯C P 一般化学实验蓝色四级实验试剂L R 一般化学实验辅助试剂棕色或其它颜色生化试剂 生化试剂 生物染色剂B R 生物化学及医用化学实验咖啡色玫瑰色_(3)High pure reagentsImpurity content:less than GR;use in trace analysis;minimize the interference fr.blank,improve the reliability of anal results.In the technical indexes,its main ingredient is quite same as GR,but marked impurity items are more than 1 2 times.（3）高纯试剂高纯试剂其最大的特点是其杂质含量比优级或基准试剂都低，用于微量或痕量分析中试样的分解和试液的制备，可最大限度地减少空白值带来的干扰，提高测定结果的可靠性。同时，高纯试剂的技术指标中，其主体成分与优级或基准试剂相当，但标明杂质含量的项目则多12倍。(4)special reagentsIt is refers to the special purpose reagents,for example,chromatographic pure reagent for chromatography&thin layer analysis as carrier,fillers&fixatives.Spectrum pure one for optical analysis;ext.It is important that the impuritiy do not generate obvious interferences in specific application.（4）专用试剂专用试剂顾名思义是指专门For CODFor COD用途的试剂。例如在色谱分析法中用的色谱纯试剂、色谱分析专用载体、填料、固定液和薄层分析试剂；光学分析法中使用的光谱纯试剂和其它分析法中的专用试剂。专用试剂除了符合高纯试剂的要求外，更重要的是在特定的用途中、其干扰的杂质成分不产生明显干扰的限度之下。1.4.2 Attention items(1)Cap(plug)in time to prevent reagent hygroscopic,stains and metamorphism after opening.(2)Put cap(plug)in right place avoiding contamination.(3)Do not reverse the reagent back after taking from original bottles.1.4.2 使用试剂注意事项1.4.2 使用试剂注意事项（1）打开瓶盖（塞）取出试剂后，应立即将瓶（塞）盖好，以免试剂吸潮、沾污和变质。（2）瓶盖（塞）不许随意放置，以免被其它物质沾污，影响原瓶试剂质量。（3）试剂应直接从原试剂瓶取用，多取试剂不允许倒回原试剂瓶。(4)Use clean dry small spoon to get solid reagents.Wash spoon immediately to lest corrosion after access strong alkaline reagents.(5)Never allow same straws for transferring two liquid reagents.(6)Certify marked label,reagent name,specifications and the date on tags before use.Do not use illegible reagent.（4）固体试剂应用洁净干燥的小勺取用。取用强碱性试剂后的小勺应立即洗净，以免腐蚀。（5）用吸管取用液态试剂时，决不许用同一吸管同时吸取二种试剂。（6）盛装试剂的瓶上，应贴有标明试剂名称、规格及出厂日期的标签，没有标签或标签字迹难以辨认的试剂，在未确定其成份前，不能随便用。1.4.3 Reagent preservationUndeserved place may cause quality and component change.Reagents should be kept in ventilation&clean house,avoid moisture&contamination of dust and other substances,and select corresponding preservation methods according to the reagent nature.1.4.3 试剂的保存1.4.3 试剂的保存试剂放置不当可能引起质量和组分的变化，因此，正确保存试剂非常重要。一般化学试剂应保存在通风良好、干净的房子里，避免水分，灰尘及其它物质的沾污，并根据试剂的性质采取相应的保存方法和措施。(1)Reagent with corrosion to glass shall be kept on plastic bottle.Such as:HF,fluoride(NaF,KF,(NH4)F),KOH,NaOH,etc.(2)Reagent with character decomposed by light,or oxidized by air,such as H2O2,HNO3,AgNO3,Gallic acid,KMnO4,H2CO4,Na2BiO4,SnCl2,FeSO4,Na2SO3,etc;and volatile Br,NH4OH and volatile organic solvents,should be kept in brown glass bottle,stored in the cold&dark place.（1）容易腐蚀玻璃影响试剂纯度的试剂，应保存在塑料瓶中。如：氢氟酸、氟化物（氟化钠、氟化钾、氟化铵）、苛性碱（氢氧化钾、氢氧化钠等。（2）见光易分解，遇空气易被氧化和易挥发的试剂应保存在棕色瓶里，放置在冷暗处。如过氧化氢（双氧水）、硝酸银、焦性没食子酸、高锰酸钾、草酸、铋酸钠等属见光易分解物质；氯化亚锡，硫酸亚铁，亚硫酸钠等属易被空气逐渐氧化的物质；溴、氨水及大多有机溶剂属易挥发的物质。(3)Reagents with feature of water imbibition(Na2CO3,NaOH,etc)should be strictly sealed&stored.(4)Regents:acid&ammonia,oxidant&reductant,could easy interact;organic solvent are inflammable;HClO4,H2O2,nitro-compound are explosive;should be separately stored in a cool ventilated place.（3）吸水性强的试剂应严格密封保存。如：无水碳酸钠，苛性钠，过氧化物等。（4）易相互作用、易燃、易爆炸的试剂，应分开贮存在阴凉通风的地方。如：酸与氨水、氧化剂与还原剂属易相互作用物质；有机溶剂属易燃试剂；氯酸、过氧化氢、硝基化合物属易爆炸试剂等。Tea break.Dangerous liquid reagent should be placed in lab low position to preventrupturing from shaking.Larger amount of flammable or poisonous liquid should be store in safe underground chemical warehouse with high duct ventilation.Std of high hiradioactive sources should be stored in a special underground hole.危险液体样品应该放在较低的安全位置，要考虑到因为震动导致破裂所带来的危害。特别对易燃的有机液体，易挥发的有毒无机液体，如数量较大，应储存在安全的有高位的通风管道地下化学品仓库。放射源标准样品要存放在专门的地下井里。(5)Reagents,such as cyanide(KCN,NaCN),HF,HgCl2,As2O3(arsenic)should specially safekeeping,strictly carry out use formality to avoid poisoning accidents.（5）剧毒试剂应专门保管，严格取用手续，以免发生中毒事故。如：氰化物（氰化钾、氰化钠氰化钾、氰化钠）、氢氟酸、二氯化汞、三氧化二砷（砒霜）氢氟酸、二氯化汞、三氧化二砷（砒霜）等属剧毒试剂。1.5 laboratory securityIt includes“water,electricity,door,window,gas,waste and reagent”.The seven words covers issues of laboratory work.They are discussed as following:1.5 实验室安全常识1.5 实验室安全常识实验室工作安全包括：“水、电、门、窗、气、废、药”。它涵盖了实验室工作中使用水、电、气体、试剂、实验过程产生的废物处理和安全防范的基本问题。1.5.1 Lab water safetyTap shall be timely closed after using,especially in case of“water stopping”.Before leaving lab,please check whether the taps are fully closed(it is easily to forget closing condenser cooling water).1.5.1.实验室用水安全1.5.1.实验室用水安全使用自来水后要及时关闭阀门，尤其遇突然停水时，要立即关闭阀门，以防来水后跑水。离开实验室之前应再检查自来水阀门是否完全关闭（使用冷凝器时较容易忘记关闭冷却水）。1.5.2 lab electricity safetyVery strict requirements are as following:(1)electric set must be professionally installed.(2)No wiring electricity at random.(3)Carefully read the instructions at first,and be in accordance with the rule to use instrument.1.5.2 实验室用电安全1.5.2 实验室用电安全实验室用电有十分严格的要求，不能随意。必须注意以下几点：（1）所有电器必须由专业人员安装；（2）不得任意另拉、另接电线用电；（3）在使用电器时，先详细阅读有关的说明书及资料，并按照要求去做；(4)Power matching should be qualified between power supply volumes and consumptions.Never overload running to reduce accident.Remember:immediately turn off the power in accident!(5)Emergency treatment in electric shock accidents:turn the power off,or with insulating objectsto pull down the power cord,or unplug(note:never unarmed to pull electrocuted person,avoid more shock accidents).Then carry the electrocuted to fresh air ASAP,（4）所有电器的用电量应与实验室的供电及用电端口匹配，决不可超负荷运行，以免发生事故。谨记：任何情况下发现用电问题（事故）时，首先先谨记：任何情况下发现用电问题（事故）时，首先先关电源！关电源！（5）发生触电事故的应急处理：如若遇触电事故，应立即使触电者脱离电源拉下电源或用绝缘物将电源线拔开（注意千万不可徒手去拉触电者，以免抢救者也被电流击倒）。注意千万不可徒手去拉触电者，以免抢救者也被电流击倒）。同时，应立即将触电者抬至空气新鲜处，Light electric shock can regain consciousness within short time.To serious electrocuted without breathing,get the electrocuted unbutton and timely perform artificial respiration and oxygen.The rescue must have patience(sometimes hours).No injection of strong heart stimulant!如电击伤害较轻则触电者短时间内可恢复知觉；若电击伤害严重或已停止呼吸，则应立即为触电者解开上衣并及时做人工呼吸和给氧。对触电者的抢救必须要有耐心（有时要连续数小时），同时忌注射强心兴奋剂忌注射强心兴奋剂。1.5.3 lab fire(heat)securityHeat source:electricity or gas.No matter what form to use,worker must pay great attention to fire(heat)rules and requirements:(1)For gas source device,should often detect pipe(gas)leak,avoid fire accident.