柠檬酸含量测量不确定度的评定

分析了测定柠檬酸含量测量不确定度的来源,评定了柠檬酸含量测定过程中测量重复性、天平、滴定管、标准溶液浓度等因素对柠檬酸含量测量不确定度的影响,计算得柠檬酸含量测定结果的扩展不确定度为0．36％。在柠檬酸含量的测定过程中,滴定管的准确度是影响柠檬酸含量测量不确定度的主要因素。     

水中高锰酸盐指数测量不确定度的评定

对GB 11892 - 1989《水质　高锰酸盐指数的测定》中酸性高锰酸钾氧化法测定水中高锰酸盐指数的测量不确定度进行了评定。通过对测量重复性、滴定管、移液管、标准溶液浓度等影响测量结果的不确定度分量的分析和量化 ,求得水中高锰酸盐指数测定结果的相对合成标准不确定度为 1.10× 10 -2 。     

生活饮用水总硬度测量结果的不确定度评定

对乙二胺四乙酸二钠滴定法测定生活饮用水总硬度的测量不确定度进行评定。分析了测量重复性、标准溶液的浓度、滴定管、取样等因素对总硬度测量不确定度的影响,求得生活饮用水总硬度测定结果的相对合成标准不确定度为2.74×10-3。     

复混肥料中氯离子含量测量不确定度的评定

对硫氰酸铵滴定法测定复混肥料中氯离子含量的测量不确定度进行了评定。分析了测量重复性、滴定管、标准溶液浓度等因素对氯离子含量测量不确定度的影响。计算得复混肥料中氯离子含量测定结果的扩展不确定度为0．049％。     

硫氰酸铵容量法测定水泥中氯离子含量的不确定度评定

依据测量不确定度的评定原理和方法,分析了测量重复性、称样、滴定管等因素对硫氰酸铵容量法测定水泥中氯离子含量的不确定度的影响,并对水泥中氯离子含量测定结果的不确定度进行了评定。     

离子色谱法测定饮用水中硝酸根离子的不确定度分析

对离子色谱法测定饮用水中硝酸根离子的不确定度进行了评定。结果表明,饮用水中硝酸根离子浓度为3.09mg/L,扩展不确定度为0.058mg/L,不确定度的主要来源包括拟合标准工作曲线产生的不确定度、标准储备溶液的制备过程带来的不确定度和仪器重复测量以及移液管使用带来的不确定度。     

水中氯化物含量测量不确定度的评定

对硝酸银滴定法测定水中氯化物含量的测量不确定度进行评定。分析了测量重复性、滴定管、标准溶液浓度等因素对氯化物含量测量不确定度的影响。计算得水中氯化物含量测定结果的相对合成标准不确定度为3.4 9× 10 -3 。     

卷烟主流烟气中NNK测量不确定度评定

对气相色谱-热能分析联用法测定卷烟主流烟气总粒相物中NNK含量的测量不确定度进行评定,分析了NNK含量检测的影响因素,计算了不确定度分量及合成不确定度,当NNK含量测定结果为27．4ng／支时,扩展不确定度为2．0ng／支。     

火焰原子吸收光谱法测定土壤中锌含量的测量不确定度评定

火焰原子吸收光谱法测定土壤中锌含量的不确定度主要来源于测量样品消解液中锌的浓度、测量过程中使用的玻璃量具及样品称量产生的不确定度,对这些分量进行了量化计算,求得合成标准不确定度和扩展不确定度分别为1．29、2．6mg／kg。影响锌含量测量不确定度的主要因素是测量样品消解液中锌的浓度引起的不确定度。     

多元素混合标准溶液中铜的不确定度评定

评定了多元素混合标准溶液中铜的不确定度。分析了混合标准溶液制备过程中不确定度的来源——所用铜片纯度、称量用电子天平、定容用移液管及容量瓶,并对各因素的影响进行了量化。计算结果表明影响合成不确定度的主要因素为制备过程中所用的玻璃量器。合成扩展不确定度为0.16%(k=2)。     

Evaluation of measurement uncertainty components associated with the results of complexometric determination of calcium in ceramic raw materials using EDTA

Calcium is an important constituent of mineral like calcite, dolomite, gypsum and bio-ceramic raw material like hydroxyapatite. Those are frequently used for the manufacture of cement, mortar, glass, synthetic ceramic bone supplement, dental enamel, etc. Determination of exact quantity of calcium in those materials is therefore very essential. The calcium content has been determined complexometrically in a ceramic raw material at pH 12, using di-sodium salt of EDTA. The major sources of uncertainty of the results of measurement are contributions from repeatability, standardization of EDTA, volume measurement by volumetric flask, burette, pipette and end point detection. Sources of uncertainty have been identified and combined by following the EURACHEM guidelines. The results show that the major sources of uncertainty arise from standardization, repeatability of the experiment and end point detection by burette. Cause–effect diagram has been drawn to explain the uncertainty budget.     

高效液相色谱法测定马来酸氯苯那敏含量的测量不确定度

分析了高效液相色谱法测定马来酸氯苯那敏含量测量不确定度的来源,评定了马来酸氯苯那敏含量测量过程中测量的重复性、天平、吸管、容量瓶、马来酸氯苯那敏对照品的纯度、对照品色谱峰面积和供试品色谱峰面积等因素对马来酸氯苯那敏含量测定不确定度的影响,计算得测定结果的相对扩展不确定度为2．0％。     

同时测定无机离子的改良离子色谱法在河水和废水质量监控中的应用（英文）

In this study,our recent work on advanced ion chromatographic methods for the simultaneous determination of inorganic ionic species such as common anions(SO2-4,Cl-and NO-3) and cations(Na+,NH+4,K+,Mg2+,and Ca2+),nutrients(phosphate and silicate) and hydrogen ion/alkalinity are summarized first.Then,the applications using these methods for monitoring environmental water quality are also presented.For the determination of common anions and cations with nutrients,the separation was successfully performed by a polymethacrylate-based weakly acidic cation-exchange column of TSKgel Super IC-A/C(Tosoh,150 mm×6.0 mm i.d.) and a mixture solution of 100 mmol/L ascorbic acid and 4 mmol/L 18-crown-6 as acidic eluent with dual detection of conductivity and spectrophotometry.For the determination of hydrogen ion/alkalinity,the separation was conducted by TSKgel ODS-100Z column(Tosoh,150 mm×4.5 mm i.d.) modified with lithium dodecylsulfate and an eluent of 40 mmol/L LiCl/0.1 mmol/L lithium dodecylsulfate/0.05 mmol/L H2SO4 with conductivity detector.The differences of ion concentration between untreated and treated wastewater showed the variation of ionic species during biological treatment process in a sewage treatment plant.Occurrence and distribution of water-quality conditions were related to the bioavailability and human activity in watershed.From these results,our advanced ion chromatographic methods have contributed significantly for water quality monitoring of environmental waters.     

火焰原子吸收光谱法测定水中锰的不确定度评定

为建立并运用火焰原子吸收光谱法测定生活饮用水中锰的不确定度评定方法,根据《不确定度评定与表示》,并参考《化学分析测量不确定度的评定指南》,对火焰原子吸收法测定生活饮用水中锰进行了不确定度的分析和评价。结果表明,合成不确定度0.006 7 mg/L,扩展不确定度0.013 mg/L。运用该不确定度评定分析方法对测量过程中的关键环节进行重点质量控制,可有效降低引入的不确定度,保证测定结果准确。     

顶空-气相色谱法测定水中卤代烃不确定度的评定

采用顶空-气相色谱法对水中三氯甲烷、一溴二氯甲烷、二溴一氯甲烷和三溴甲烷4种卤代烃测定结果的不确定度进行了评定,并对测量重复性、标准差、标准溶液浓度等影响测量结果的不确定度分量进行了分析和量化。当水中三氯甲烷、一溴二氯甲烷、二溴一氯甲烷和三溴甲烷测定结果为18.58、12.74、21.00、18.43μg/L时,其扩展不确定度分别为3.32、2.96、3.14、3.00μg/L(k=2)。     

毛细滴管数滴微型滴定法野外快速测定水中溶解氧

用毛细滴管数滴微型滴定法对水中溶解氧进行了现场快速测定。实验结果表明,该法的不确定度Urel(C)约为1.6%,与常量滴定法相当,符合国家标准。该法以自制的液滴体积为0.01~0.02 mL的聚乙烯毛细滴管就地进行滴定,避免了水样长期保存和运输中产生的误差。其主要仪器外形小巧、便于携带,滴定快速、准确,滴定剂用量仅为65~100滴,完全能够满足现场快速水质测定和野外水环境监测的需要。     

碘量法测定水中溶解氧含量测量不确定度的评定

分析碘量法测定水中溶解氧含量测量不确定度的影响因素，对测量不确定度各个分量的评定结果表明，测量重复性的不确定度分量最大，其次是样品溶液的体积、滴定溶液的体积和滴定溶液的浓度等不确定度分量，计算得到水中溶解氧含量测定结果的合成不确定度为0．06mg/L，扩展不确定度为0．12mg/L。     

Estimation of uncertainty in p<Emphasis Type="Italic">K</Emphasis><Subscript>a</Subscript> values determined by potentiometric titration

A procedure is presented for estimation of uncertainty in measurement of the pK(a) of a weak acid by potentiometric titration. The procedure is based on the ISO GUM. The core of the procedure is a mathematical model that involves 40 input parameters. A novel approach is used for taking into account the purity of the acid, the impurities are not treated as inert compounds only, their possible acidic dissociation is also taken into account. Application to an example of practical pK(a) determination is presented. Altogether 67 different sources of uncertainty are identified and quantified within the example. The relative importance of different uncertainty sources is discussed. The most important source of uncertainty (with the experimental set-up of the example) is the uncertainty of pH measurement followed by the accuracy of the burette and the uncertainty of weighing. The procedure gives uncertainty separately for each point of the titration curve. The uncertainty depends on the amount of titrant added, being lowest in the central part of the titration curve. The possibilities of reducing the uncertainty and interpreting the drift of the pK(a) values obtained from the same curve are discussed.