Modern analytical chemistry education in Europe at university level

Stimulated by the rapid growth of analytical chemistry in research and development, a discussion on the past, present and future role of analytical chemistry as part of the chemistry curricula at European universities is presented in this article. The present status of analytical chemistry curricula is described, based on a recent investigation of the Working Party on Analytical Chemistry (WPAC) of the Federation of European Chemical Societies (FECS) at 229 European universities. The evaluation of the questionnaires has been done for all institutions together, as well as for the 119 institutions with a separate chair or department of analytical chemistry and the 110 institutions without such a separate chair. The distribution of teaching hours between the classical and modern fields is generally significantly better and more flexible to new developments (like chemometrics, environmental and material sciences) at institutions with an own chair of analytical chemistry. This survey is also a key to earlier reviews on education in analytical chemistry stimulated and published by WPAC-members.     

Multivariate data analysis of quality parameters in drinking water

The quality of water destined for human consumption has been treated as a multivariate property. Since most of the quality parameters are obtained by applying analytical methods, the routine analytical laboratory (responsible for the accuracy of analytical data) has been treated as a process system for water quality estimation. Multivariate tools, based on principal component analysis (PCA) and partial least squares (PLS) regression, are used in the present paper to: (i) study the main factors of the latent data structure and (ii) characterize the water samples and the analytical methods in terms of multivariate quality control (MQC). Such tools could warn of both possible health risks related to anomalous sample composition and failures in the analytical methods.     

High performance liquid chromatography coupled to an optical fiber detector coated with laccase for screening catecholamines in plasma and urine

An analytical method based on separation by high performance liquid chromatography (HPLC) and detection by optical fiber (OF) coated with an enzyme (laccase), has been developed for separation and quantification of catecholamines, namely epinephrine, dopamine and norepinephrine. The application of OF as a detector in this analytical system relies on the variation of the reflected optical power detected when the catecholamines eluted from the HPLC column act as the substrate of the laccase immobilized on a tip of a single-mode OF. The developed method shows a high linearity in a range between 5 and 125 pg/mL and detection limits of 3.5, 2.9 and 3.3 pg/mL for epinephrine, dopamine and norepinephrine, respectively. The analytical performance of the proposed method was compared with a classical analytical method, namely high performance liquid chromatography-electrochemical detector (HPLC-ED) regarding catecholamines detection, showing great analytical advantages such as low cost of equipment. Additionally, the proposed method was applied to catecholamines determination in actual samples of plasma and human urine.     

Field-flow fractionation: Analytical and micropreparative methodology

Since the introduction of the general concept, field-flow fractionation (FFF) was developed to a complex of separation methods that differ by the fundamental processes underlying and accompanying the separation. In this review, the basic principles on which this separation methodology lies are presented, the most important methods and techniques applicable for analytical and preparative fractionations are described, the first approximation theoretical treatment of the separation processes is outlined, and typical applications for analytical and micropreparative purposes are demonstrated. The main goal is to show that FFF represents an interesting and competitive option of the separation methods applicable in analytical chemistry. The existence of some conflicting opinions concerning the theory as well as the experiments does not prohibit the analytical and preparative use of FFF. If not regarded only as a routine analytical tool, it should stimulate the research and development efforts. On the other hand, when used as an analytical tool, even if the approximate theoretical models are not fully supported by the experiments, the correct analytical result can be obtained from FFF (as well as from any other analytical separation method) by using a calibration procedure and an appropriate treatment and interpretation of the raw experimental data.     

Assuring trueness of analytical results

Summary A true analytical result presumes an analytical procedure without systematic errors. They can be detected by comparing the analytical results with the true value or with an accepted reference. Systematic errors are always superimposed by the random error, therefore such a comparison must include statistical tests. The paper describes suitable test-models for typical analytical problems, as e.g. the validation of an analytical procedure or the (current) control of analytical work. Furthermore, explanations will be given for the interpretation of the test results due to the trueness of analytical data and for the consequences concerning analytical work.     

High NIR-purity index single-walled carbon nanotubes for electrochemical sensing in microfluidic chips

Single-walled carbon nanotubes (SWCNTs) should constitute an important natural step towards the improvement of the analytical performance of microfluidic electrochemical sensing. SWCNTs inherently offer lower detection potentials, higher surfaces and better stability than the existing carbon electrodes. However, pristine SWCNTs contain some carbonaceous and metallic impurities that influence their electrochemical performance. Thus, an appropriate processing method is important for obtaining high purity SWCNTs for analytical applications. In this work, a set of 0.1 mg mL(-1) SWCNT dispersions with different degrees of purity and different dispersants (SDBS; pluronic F68 and DMF) was carefully characterized by near infrared (NIR) spectroscopy giving a Purity Index (NIR-PI) ranging from 0.039 to 0.310. The highest purity was obtained when air oxidized SWCNTs were dispersed in SDBS, followed by centrifugation. The SWCNT dispersions were utilized to modify microfluidic chip electrodes for the electrochemical sensing of dopamine and catechol. In comparison with non-SWCNT-based electrodes, the sample with the highest NIR-PI (0.310) exhibited the best analytical performance in terms of improved sensitivity (3-folds higher), very good signal-to-noise ratio, high resistance-to-fouling in terms of relative standard deviation (RSD 7%; n = 15), and enhanced resolution (2-folds higher). In addition, very well-defined concentration dependence was also obtained with excellent correlation coefficients (r ≥ 0.990). Likewise, a good analytical sensitivity, suitable detection limits (LODs) and a very good precision with independence of the concentration assayed (RSDs ≤ 5%) was achieved. These valuable features indicate the suitability of this material for quantitative analysis. NIR-PI and further TEM and XRD characterization demonstrated that the analytical response was driven and controlled by the high NIR-PI of the SWCNTs used. The significance of this work is the demonstration for the first time of the sensitivity-purity relationship in SWCNT microfluidic chips. A novel and valuable analytical tool for electrochemical sensing has been developed: SWCNTs with high purity and a rich surface chemistry with functional groups, both essential for analytical purposes. Also, this work helps to better understand the analytical potency of SWCNTs coupled to microfluidic chips and it opens new gates for using these unique dispersions in real-world applications.     

Analytical Method Development for 19 Alkyl Halides as Potential Genotoxic Impurities by Analytical Quality by Design

Major issues in the pharmaceutical industry involve efficient risk management and control strategies of potential genotoxic impurities (PGIs). As a result, the development of an appropriate method to control these impurities is required. An optimally sensitive and simultaneous analytical method using gas chromatography with a mass spectrometry detector (GC–MS) was developed for 19 alkyl halides determined to be PGIs. These 19 alkyl halides were selected from 144 alkyl halides through an in silico study utilizing quantitative structure–activity relationship (Q-SAR) approaches via expert knowledge rule-based software and statistical-based software. The analytical quality by design (QbD) approach was adopted for the development of a sensitive and robust analytical method for PGIs. A limited number of literature studies have reviewed the analytical QbD approach in the PGI method development using GC–MS as the analytical instrument. A GC equipped with a single quadrupole mass spectrometry detector (MSD) and VF-624 ms capillary column was used. The developed method was validated in terms of specificity, the limit of detection, quantitation, linearity, accuracy, and precision, according to the ICH Q2 guideline.     

微流控细胞芯片LED诱导荧光检测微系统

基于微流控细胞芯片分析技术和微机电系统(MEMS)加工技术, 设计制作了阵列式微流控细胞检测芯片, 采用自组装的顶窗型光电倍增管(PMT)和信号采集电路采集芯片微管道内流动细胞的荧光信号, 构建了一种针对低浓度细胞悬浮液的微流控细胞芯片发光二极管(LED)诱导荧光的快速检测微系统, 实现了对低浓度(≤40 Cell/mL)荧光标记的HepG2肝癌细胞悬浮液样本的定量计数和测试, 而且在血液细胞共存的条件下, 仍可以有效地对血液中少量HepG2肝癌细胞进行荧光计数和测试. 整个系统结构简单, 操作方便且检测灵敏度较高.     

Recognizing heterogeneous distribution of platinum group elements (PGE) in geological materials by means of the Re-Os isotope system

The identification of uncertainties caused by sample inhomogeneity, as distinct from those caused by sample preparation and measurement, is a challenging task. Use of chemometric methods to separate and estimate these contributions to the combined standard uncertainty of a measurement (uc) of an analytical result requires complex experiments. The difficulty of platinum group element measurement makes this task even more complex. But unless it can be demonstrated that sample inhomogeneity is the major contributor to the high variability of an analytical result one should be careful not to mistakenly attribute this to a nugget effect. In this contribution we are able to demonstrate in two special cases that irreproducible results (up to 90% RSD) for analysis of Os and Re in the pg g(-1) to ng g(-1) range are truly caused by a nugget effect and not by inadequacies of the analytical method.     

Are there two decks on the analytical chemistry boat?

 This paper examines some problems of implementation of quality assurance (QA) principles in chemical measurement in the university academic environment. Being developed and introduced in practice by industrial and independent commercial laboratories, the 'quality lifestyle' has been largely ignored by the academic analytical community. The academic community is now faced with the fact that teaching, education and training of analytical QA and analytical quality management are no longer a matter of choice.     

Accurate determination and certification of bromine in plastic by isotope dilution inductively coupled plasma mass spectrometry

The accurate analytical method of bromine (Br) in plastic was developed by an isotope dilution inductively coupled plasma mass spectrometry (ID-ICPMS). The figures of merit of microwave acid digestion procedures using polytetrafluoroethylene (PTFE) or quartz vessels were studied and the latter one was suitable for Br analysis since its material was free from Br contamination. The sample dilution procedures using Milli-Q water or ammonium (NH₃) solution were also studied to remove memory effect for ICPMS measurement. Although severe memory effect was observed on Milli-Q water dilution, NH₃ solution could remove it successfully. The accuracy of the ID-ICPMS was validated by a certified reference material (CRM) as well as the comparison with the analytical result obtained by an instrumental neutron activation analysis (INAA) as different analytical method. From these results, the ID-ICPMS developed in the present study could be evaluated as accurate analytical method of Br in plastic materials and it could apply to certification of Br in candidate plastic CRM with respect to such regulations related to RoHS (restriction of the use of hazardous substances in electrical and electronics equipment) directive.     

两种轻烃分析方法(“PTV切割反吹”和“顶空”)的对比研究

 建立了“程序升温蒸发进样器 (PTV)切割反吹”和“顶空”两种有关原油中轻烃的分析方法 ,色谱柱的使用寿命长、分析周期短 ,原油中 < ,将原油直接注入汽化室所得的分析数据较可靠 ,并对引起误差的原因进行了探讨。指出用这两种方法所获得的数据是不能合在一起作地化研究的 ) % 5 2 1%～ ( 19个地化参数的相对误差范围约为± 10个油样用两种分析方法所得 6个油区的 ,还报道了采自我国 ,并有良好的重复性。。     

Strategies to set global analytical quality specifications in laboratory medicine: 10 years on from the Stockholm consensus conference

The setting of analytical quality specifications in laboratory medicine has attracted attention for many years. Over time, many strategies were advocated and all had advantages and disadvantages. In the final decade of the last millennium, considerable confusion existed on how to define analytical quality specifications correctly and how to apply them in everyday practice. This led to wide professional interest. In 1999, a consensus conference sponsored by IUPAC, IFCC and WHO was held in Stockholm on “Strategies to Set Global Analytical Quality Specifications in Laboratory Medicine”. The consensus set useful and well-documented strategies for the setting of analytical quality specifications into a hierarchy with the best strategy at the highest level, namely, (1) Evaluation of the effect of analytical performance on clinical outcomes in specific clinical situations, (2) Evaluation of the effect of analytical performance on clinical decisions in general, (3) Published professional recommendations, (4) Performance goals set by regulatory bodies and EQAS organisers, and (5) Goals based on the current state of the art. Much success has been achieved since the promulgation of the statement with the approach being adopted by many in laboratory medicine for a very wide variety of purposes, particularly in quality management. However, there is a requirement for additional investigation of, inter alia, quality specifications for examinations done on measurements performed on ordinal and nominal scales, pre-analytical factors and matrix effects, examinations done as POCT, target values of control materials, and ways in which analytical quality specifications can be used both to set what is the optimum performance and as a tool for assessment of everyday practice.     

全自动在线固相萃取-高效液相色谱法测定水体中痕量微囊藻毒素

建立了全自动化在线固相萃取-高效液相色谱法快速、准确测定水体中3种痕量微囊藻毒素的新方法.样品用自动进样器连续注入固相萃取小柱完成富集后,通过双梯度高效液相系统中的一个泵(上样泵)实现净化,再通过阀切换将固相萃取小柱切换至分析流路中,用另一个泵(分析泵)将待测物冲洗至分析柱进行测定.方法使用Acclaim PA柱芯(1...     

分析型色谱饼对人血清白蛋白的快速纯化

采用分析型色谱饼对标准蛋白混合物进行了分离,结果表明装填有小颗粒填料的色谱饼在高流速条件下仍然具有良好的分离能力。在较大流速(5 mL/min)条件下,在10 min内对人血清白蛋白样品进行了快速纯化,其纯化后的人血清白蛋白的纯度大于85%,回收率为65%,说明分析型色谱饼可以用于快速分离纯化生物大分子。     

Informationsgewinn bei analytisch-chemischen Messungen

Summary The aim of every analytical experiment is to gain information about a particular chemical system. In order to design and carry out such an experiment it is necessary to take into consideration the chemical properties of the matter as well as the metrological rules inherent in the analytical method applied. In this aim (to obtain information) and in the manner of working (to regard chemical properties and metrological rules) analytical chemistry can be seen as being a uniform and independent scientific discipline. The different analytical methods and the numerous analytical problems can then be described in uniform manner. The different measuring parameters and steps in analytical work can all be reduced to uniform terms and processes. The treatment and evaluation of the signal produced in the analytical experiment is always at the centre of all discussions. The uniform theoretical interpretation of seemingly different methodological terms makes a standardized nomenclature possible. The aim of effectively obtained information explains the preference of certain analytical methods for trace analysis, structure analysis, multicomponent analysis or other analytical problems. Furthermore, it is possible to derive useful strategies for applying an analytical method or managing an analytical problem. Finally, tendencies can be shown for the development of analytical methods, which are particularly effective in obtaining information.     

A new strategy of solution calibration in laser ablation inductively coupled plasma mass spectrometry for multielement trace analysis of geological samples

Because multielement trace analysis by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) is often limited by the lack of suitable reference materials with a similar matrix composition, a novel quantification strategy using solution calibration was developed. For mass spectrometric multielement determination in geological samples a quadrupole-based LA-ICP-MS is coupled with an ultrasonic nebulizer (USN). In order to arrange matrix matching the standard solutions are nebulized with a USN during solution calibration and simultaneously a blank target (e.g. lithium borate) is ablated with a focused laser beam. The homogeneous geological samples were measured using the same experimental arrangement where a 2% nitric acid is simultaneously nebulized with the USN. Homogeneous targets were prepared from inhomogeneous geological samples by powdering, homogenizing and fusing with a lithium borate mixture in a muffle furnace at 1050 degrees C. Furthermore, a homogeneous geological glass was also investigated. The quantification of analytical results was performed by external calibration using calibration curves measured on standard solutions. In order to compare two different approaches for the quantification of analytical results in LA-ICP-MS, measured concentrations in homogeneous geological targets were also corrected with relative sensitivity coefficients (RSCs) determined using one standard solution only. The analytical results of LA-ICP-MS on various geological samples are in good agreement with the reference values and the results of other trace analytical methods. The relative standard deviation (RSD) for trace element determination (N = 6) is between 2 and 10%.