In the recent years, attention for fast separation of all kind of samples in combination with automated systems has increased. On that account we designed and constructed a miniaturized capillary electrophoresis system which can achieve fast separations due to short capillary length and high electric field strength. An integrated and exchangeable autosampler unit which can be loaded with 19 samples at once allowed high-throughput measurements with small sample volumes down to 30 mm3. The design of the device enables the implementation of various detectors. The aim of this work was the analytical characterization of this device in combination with mass spectrometry, amperometric and capacitively coupled contactless conductivity detection. Hydrodynamic and electrokinetic injections were carried out with different injection parameters. Different model systems for each detection technique were used to test the performance of the device, concerning speed of separation, precision, resolution, and sample throughput.

In this report, a versatile experimental concept for electrochemical deposition and subsequent surface characterization studies is presented. This concept can be utilized to perform semiconductor plating processes at laboratory scale followed by scanning electrochemical microscopy (SECM). The same sample holder used for electroplating experiments could be integrated into the SECM instrument. Conductive thin-film barrier materials were deposited on planar silicon wafers. The substrate samples were fixed in the multipurpose sample holder ensuring a large electrical contact area to minimize ohmic drop across the sample surface with a small circular area of the substrate material of 16 mm2 exposed to electrolyte solution. In order to investigate the capabilities of the electrochemical cell configuration, a potentiostatic copper deposition on ruthenium was carried out. Thus, information on film coalescences, grain size, and growth mode could be derived. SECM was used to study the effect of biasing during probe approach curves on a titanium surface. Furthermore, microstructured copper layers were imaged using ferrocenemethanol (FcMeOH) as mediator. The results show that biasing the substrate is essential for non-destructive and interaction-free measurements of semiprecious thin-film materials and copper structures, if FcMeOH is used as electrochemical mediator.Schematic diagram of multipurpose electrodeposition cell configuration.

In today’s industry, quick and reliable analytical methods play an important role for quality control. On that account, two emerging techniques, namely direct inlet probe-atmospheric pressure chemical ionization (DIP-APCI) and direct analysis in real time (DART) mass spectrometry, are particularly promising. In case of a DIP-APCI source, small amounts of solid or liquid samples can be studied without sample pre-treatment. A similar system is the DART ion source. In addition to the analysis of solid and liquid samples without pre-separation, this ion source offers the possibility to scan the surface of a sample. A method for industrial sample analysis focusing on the study of delamination of coatings from a panel was developed using DIP-APCI-Q-TOF-MS and DART-Q-TOF-MS, respectively. Comparative studies based on the conventional pyrolysis–GC–MS were carried out.

This review discusses advances in the field of high resolution scanning electrochemical microscopy (HR-SECM) and scanning ion conductance microscopy (SICM) to study living cells. Relevant references from the advent of this technique in the late 1980s to most recent contributions in 2012 are presented with special discussion on high resolution images. A clear progress especially within the last 5 years can be seen in the field of HR-SECM. Furthermore, we also concentrate on the intrinsic properties of SECM imaging techniques e.g. different modes of image acquisition, their advantages and disadvantages in imaging living cells and strategies for further enhancement of image resolution, etc. Some of the recent advances of SECM in nanoimaging have also been discussed which may have potential applications in high resolution imaging of cellular processes.Graphical abstractHigh resolution scanning electrochemical microscopy (SECM) is a rapidly developing tool for studies of living cells. Various methodical approaches of SECM imaging can be used to gain detailed information concerning the morphology and function of single cell and cell assemblies.Highlights► We discuss recent advances in high resolution SECM of living cells. ► Advantages and disadvantages of the various imaging techniques are compared. ► New horizons in high resolution SECM studies of cellular processes are discussed.

•Separation of organotin species with CE-TOF-MS in water samples. Experiments were made with a special laboratory constructed CE instrument.•Detection limits of the CE-TOF-MS method were between 1 and 8×10−7 M, and between 2 and 11×10−9 M when used in conjunction with a solid phase extraction method.•“TOF-MS allowed unambiguous differentiation between analytes and matrix components”.•The short analysis time and high sensitivity make it a useful approach for the analysis of the organotin compounds.A novel approach has been developed for the separation of organotin species with capillary electrophoresis hyphenated to time-of-flight mass spectrometry. It has been applied to the development of a method for the determination and speciation of organotin compounds namely, dibutyltin (DBT), tributyltin (TBT), diphenyltin (DPT) and triphenyltin (TPT) in water samples. Experiments were made with a special laboratory constructed CE instrument. A non-aqueous buffer system compatible with TOF-MS has been developed using ammonium acetate–acetic acid (50 mM and 1 M) in acetonitrile: methanol (80:20). The total analysis time is less than 3 min for these compounds under the conditions developed. The method has been applied successfully to the determination of these compounds in river water samples. Detection limits of the CE-TOF-MS method were between 1 and 8×10−7 M, and between 2 and 11×10−9 M (0.46 to 3.2 µg L−1) when used in conjunction with solid phase extraction. The short analysis time as well as good sensitivity and selectivity make it a useful approach for the fast screening of organotin compounds.A novel approach for the speciation of organotin compounds with capillary electrophoresis hyphenated to time-of-flight mass spectrometry has been developed. It has been applied to the determination of dibutyltin (DBT), tributyltin (TBT), diphenyltin (DPT) and triphenyltin (TPT) in water samples. Experiments were made with a special laboratory-constructed CE instrument enabling fast CE-MS measurements. Detection limits of the CE-TOF-MS method were between 1 and 8×10−7 M, and between 2 and 11×10−9 M when used in conjunction with solid phase extraction. The short analysis time and good sensitivity and selectivity make it a useful approach for the screening of organotin compounds in environmental samples.

Electromigrative techniques such as capillary and microchip electrophoresis (CE and MCE) are inherently associated with various electrochemical phenomena. The electrolytic processes occurring in the buffer reservoirs have to be considered for a proper design of miniaturized electrophoretic systems and a suitable selection of buffer composition. In addition, the control of the electroosmotic flow plays a crucial role for the optimization of CE/MCE separations. Electroanalytical methods have significant importance in the field of detection in conjunction with CE/MCE. At present, amperometric detection and contactless conductivity detection are the predominating electrochemical detection methods for CE/MCE. This paper reviews the most recent trends in the field of electrochemical detection coupled to CE/MCE. The emphasis is on methodical developments and new applications that have been published over the past five years. A rather new way for the implementation of electrochemical methods into CE systems is the concept of electrochemically assisted injection which involves the electrochemical conversions of analytes during the injection step. This approach is particularly attractive in hyphenation to mass spectrometry (MS) as it widens the range of CE–MS applications. An overview of recent developments of electrochemically assisted injection coupled to CE is presented.Highlights► Electromigrative techniques are inherently associated with electrochemical phenomena. ► Amperometric and contactless conductivity detection are most often used. ► Electrochemically assisted injection is as a new electroanalytical concept for CE.

We present an experimental approach to conducting fast capillary electrophoresis–mass spectrometry (CE-MS) measurements of very small samples in the nanoliter range. This is achieved by injecting sample very efficiently into a CE-MS system. Injection efficiency represents the ratio of injected sample to the amount of sample needed for carrying out the injection process (v/v). In order to increase this injection efficiency from typical values of 10–3 to 10−7, the concept of capillary batch injection is used to build an automated, small-footprint injection device for CE-MS. This device is capable of running true multi-sample measurement series, using minimal sample volumes and delivering an injection efficiency of up to 100 %. It is compatible with both aqueous and non-aqueous background electrolytes. As an additional benefit, CE-MS separations of a catecholamine model system in capillaries of 15 cm length under conditions of high electric field strength could be accomplished in 20 s with high separation efficiency. This report details design and specifications of the injection device and shows optimal parameter choices for injections with both high injection efficiency and high separation efficiency. Furthermore, a procedure is presented to coat the tip of a fused silica capillary with a silicone elastomer which acts as a seal between two capillaries.

Capillary electrophoretic separations performed in short capillaries under high field strengths have recently emerged as a promising alternative to chip-based separations. However, the injection and detection approaches have to be adapted appropriately to enable high-throughput determinations. This paper addresses current challenges and trends in this field of research.