化学检测实验室内部质量控制方式探讨及结果评价

质量控制是指实验室利用现代科学管理的方法和技术控制与分析有关的各个环节,目的是把分析测试的误差控制在允许的范围内,保证分析的准确度和精密度,它贯穿于实验室全部质量活动的始终,包括分析前质量保证、分析中质量控制和分析后质量评估三个阶段。其中分析中质量控制又称检测结果的质量保证,实验室的其它质量活动对其提供保证或促进作用。本文从质量控制图、标准物质、回收试验、实验     

火焰原子吸收法连续测定镉镍浸渍液中镁钾钙铁

火焰原子吸收光谱法连续测定镉镍浸渍液中镁、钾、钙和铁是一种非常有效的仪器分析方法 ,该方法灵敏度高 ,分析精度好 ,分析速度快。以往采用的比色法和容量法 ,不仅操作繁杂 ,分析要求也极为严格 ,稍有不慎便会带来误差。本文用火焰原子吸收光谱法对镉镍浸渍液中镁、钾、钙和铁连续测定 ,并对测定条件、干扰因素进行了综合试验。各元素测定的相对标准偏差小于 1 .0 % ( n=1 0 ) ,标准加入回收率在 97%～ 1 0 3%内。方法简便、快速 ,适用于多元素镉镍浸渍液生产控制分析和样品系统分析。1　试验部分1 .1　仪器与试剂AA- 670型 ( Shimadzu)…     

用质量控制图监控饮用水高锰酸盐指数检测质量

为确保饮用水中高锰酸盐指数检测结果准确可靠,以GB/T 11892–1989方法《水质高锰酸盐指数的测定》为试验方法,每日对同一质量浓度质控样品平行测定2~3次,统计30组有效数据,通过计算平均值、标准偏差得出上下控制限、警告限和辅助线,绘制出现有实验室人员测试技术水平、试剂、设备、分析方法和环境因素条件下的质量控制图。该质量控制图不仅用于实际检测过程中对检测结果进行监控,还可为实验室的人员分析技能考核、比对监测等分析质量控制行为提供结果判定的依据。     

《分析测试统计方法和质量控制》书讯

<正>曹宏燕等编著。《分析测试统计方法和质量控制》全书分十三章,七十三万余字,介绍了分析测试及其试验研究中常用的数理统计方法,包括误差和误差的分布、统计检验、方差分析、正交设计、回归分析等统计方法的理论与实践。本书紧密结合国际标准(ISO)、国家标准(GB)及中国合格评定国家认可委员会(CNAS)等有关实验室管理规范、标准和认可要求,阐述了实验室协同试验和管理中测量结果精密度试验和应用、能力验证及其稳健统计、测量不确定度评定、标准物质研制及应用、分析方法的评价及分析结果的表     

电感耦合等离子体质谱法测定钨矿石、钼矿石中铼的方法确认

本文在修订国家标准 GB/T 14352.18－2010《钨矿石、钼矿石化学分析方法第18部分：铼量测定》研究工作中,不再使用原先的有机试剂萃取-比色法测定的方法,建立了用氧化镁烧结分解-水提取,ICP-MS法测定钨矿石、钼矿石中铼的分析方法。测定范围为0.05 μg/g～300 μg/g,检出限为0.005μg/g。根据规范要求开展了8 个实验室协同参加的准确度试验,统计参数显示,大量测试结果的算术平均值与标准值之间有较好的一致性,测量方法对铼在限定水平的检测偏倚不显著,分析方法精密度满足《地质矿产实验室测试质量管理规范》的要求。     

TMB法测定水中游离余氯的改进

介绍了一种改进试剂后测定水中游离余氯的TMB比色法。结果表明，其检测过程快速、便捷；精密度和准确度均能达到分析要求。     

车间空气中酚浓度测定方法改进

对于车间空气中酚浓度的测定,目前采用DB14/35-41-1999《工业劳动卫生监测监护规范》的方法,此方法采用串联吸收管采样,操作繁琐,且在分析过程中对样品溶液的pH值控制不严,溶液的pH值对测定影响很大,当pH<7.4时,两个分子的4-氨基安替比林缩合成红色安替比林染料,使空白值增加,在pH 9~10.7时,酚与4-氨基安替比林生成物的颜色最深,所以测定时应严格控制pH 10±0.2,本文对原方法进行了改进,经过多次试验证明,改进后的方法准确度、精密度及线性均较好。1试验部分[1]1.1主要仪器与试剂KC-6D型大气采样器721型分光光度计气泡吸收管吸收液:pH …     

浅谈食品理化检测实验室质量控制

实验室质量控制是指实验室利用现代科学管理的方法和技术,控制与分析有关的各个环节,目的是把分析测试的误差控制在允许的范围内,保证分析的准确度和精密度,使分析数据在给定的置信水平内能达到要求的质量。质量控制又有广义和狭义之分,广义的质量控制贯穿于实验室全部质量活动的     

纳氏试剂分光光度法测定氨氮中常见问题与解决办法

纳氏试剂比色法是测定水中氨氮的国家标准方法[1],本文在了解其他纳氏试剂比色法测定氨氮的方法研究的基础上,根据实际工作经验,对纳氏试剂比色法测定水体中氨氮常见问题进行了总结,以便更好的指导实际工作.     

《分析测试统计方法和质量控制》书讯

正曹宏燕等编著。《分析测试统计方法和质量控制》全书分十三章,七十三万余字,介绍了分析测试及其试验研究中常用的数理统计方法,包括误差和误差的分布、统计检验、方差分析、正交设计、回归分析等统计方法的理论与实践。本书紧密结合国际标准(ISO)、国家标准(GB)及中国合格评定国家认可委员会(CNAS)等有关实验室管理规范、标准和认可要求,阐述了实验室协同试验和管理中测量结果精密度试验和应用、能力验     

HEPT类化合物的QSAR研究

为定量结构／活性相关性研究提取了量子化学参数,拓扑指数Am,分子连接性指数^mxt及疏水性常数,同时应用正交变换和最佳变量子集算法（Leaps-and-Bonds)进行了变量压缩和选择,进而实施了多元回归分析,并由此结果进行了HEPT类化合物（1－[(2-hydroxyethoxy)methyl]-6-(phenylthio)-thymine derivatives)的结构／活性关系的理论解释,进行了人工神经网络法对于该类化合物的活性预测,其结构明显好于多元回归法。     

Effect of the pH of the medium on the chemical shifts in the PMR spectra and on the distribution of the π-electron density

The dependence of the chemical shifts of the ring protons on the pH of the medium for a number of 4-hydroxyquinoline derivatives was studied by means of PMR spectroscopy. The dipolar and uncharged hydroxy forms exist in equilibrium in aqueous solutions. The effect of intramolecular hydrogen bonding on the character of the dependence of the chemical shift on the pH of the medium in the case of 3-piperidinomethyl-4-hydroxyisoquinoline was investigated. The possibility of the separate protonation of the ring nitrogen and the side-chain nitrogen in 3-piperidinomethyl-4-hydroxyisoquinoline was established. The distribution of the -electron density in 4-hydroxyisoquinoline is in good agreement with its chemical behavior.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1546–1549, November, 1971     

Effect of the pH of the medium on the chemical shifts in the PMR spectra and on the distribution of the π-electron density

The dependence of the chemical shift of the ring protons on the pH of the medium for a number of 3-hydroxyquinoline derivatives was studied by PMR spectroscopy. The regions of ionization of the molecules, which correspond to the ranges of acidic, neutral, and alkaline media, were found. In D₂O, 3-hydroxyquinoline is present only in the uncharged hydroxy form. The presence of intramolecular hydrogen bonding in 4-dimethylaminomethyl-3-hydroxyquinoline has a substantial effect on the character of the dependence of the chemical shift on the pH of the medium; the existence of separate protonation of the nitrogen atoms of the ring and the side chain of 4-dimethylaminomethyl-3-hydroxyquinoline was established. The distribution of the -electron density in the 3-hydroxyquinoline molecule is in good agreement with its chemical behavior during electrophilic substitution.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1540–1545, November, 1971.     

液滴荧光传感与计算机联用技术在微量分析中的应用

通过在LS55型荧光-磷光-发光分光光度计上加装液滴产生及调节附件,采用计算机采集与分析处理数据,成功地研制了双通道液滴光化学传感装置.利用葡聚糖凝胶对复合维生素B中不同组分的选择性吸附来达到分离与同时检测的目的,并将其用于复合维生素B药片的分析,取得了满意的结果.     

On the theory underlying the Car-Parrinello method and the role of the fictitious mass parameter

The theory underlying the Car-Parrinello extended-Lagrangian approach to ab initio molecular dynamics (CPMD) is reviewed and reexamined using "heavy" ice as a test system. It is emphasized that the adiabatic decoupling in CPMD is not a decoupling of electronic orbitals from the ions but only a decoupling of a subset of the orbital vibrational modes from the rest of the necessarily coupled system of orbitals and ions. Recent work [J. Chem. Phys. 116, 14 (2002)] has pointed out that, due to the orbital-ion coupling that remains once adiabatic decoupling has been achieved, a large value of the fictitious mass mu can lead to systematic errors in the computed forces in CPMD. These errors are further investigated in the present work with a focus on those parts of these errors that are not corrected simply by rescaling the masses of the ions. It is suggested that any comparison of the efficiencies of Born-Oppenheimer molecular dynamics (BOMD) and CPMD should be performed at a similar level of accuracy. If accuracy is judged according to the average magnitude of the systematic errors in the computed forces, the efficiency of BOMD compares more favorably to that of CPMD than previous comparisons have suggested.     

From the Micro- to the Macro-: Managing the Conservation of the Warship,Vasa

Sweden's famous warship, Vasa, sank on her maiden voyage in August 1628, and remained on the bottom of Stockholm harbour for 333 years. Raised in 1961, she became the first large-scale wooden object to be treated with polyethylene glycol (PEG). In the summer of 2000 a number of acidic salt precipitations were noticed on the surface of the ship and on wooden artefacts in the storerooms. An international research project has been established to look into the causes of this problem and suggest possible re-treatments. Meanwhile projects are underway to monitor movements in the ship, to build a better support system, and to replace the thousands of iron bolts holding the structure together, while a sophisticated new climate system has recently been installed in the museum.