Equipment qualification and its application to conductivity measuring systems

It is only possible to obtain analytical results that are suitable for their intended purpose if the equipment used is capable of producing measurements of the required quality. To ensure that this requirement is met, analysts should define the performance criteria required from the instruments, ensure that only suitable instruments are selected for analytical measurements, and confirm that these instruments continue to meet these criteria for their entire operational life. This process should be conducted on a formal, documented basis, known as equipment qualification. In addition to describing the key elements of equipment qualification for all analytical instruments, this paper gives specific guidance on its application to conductivity systems that has never previously appeared in the literature. The benefits of performing equipment qualification are highlighted and guidance is given on the selection of control standards and why the equipment vendor performing stages of equipment qualification can be of benefit to the user. The relationship between equipment qualification and method validation is discussed, including how these activities play a major role in determining the quality control measures that should be applied to routine analysis.     

实验室信息管理系统中仪器设备管理模块的设计与实现

根据资质认定、实验室认可要求,从仪器设备管理的要求和仪器设备管理工作实际出发,归纳了实验室仪器设备管理、计量溯源方面的要求以及管理环节中容易出现的问题,采用用户界面(user interface,UI)插件技术和Gojs技术开发了信息管理系统仪器设备管理模块,降低了系统维护的难度,满足了系统使用的个性化需求,实现了仪器...     

A new concept for stress relaxation measurements of rubbers in compression

Current relaxation measurements and associated equipment are not reliable enough to carry out prolonged tests, especially at high temperatures and in liquid environments; the difficulties encountered in such measurements are discussed. The objectives of the present sponsored programme were to examine the best available equipment and experimental techniques and to develop a reliable and reproducible method for measuring stress relaxation in compression which could form a basis for a standard test procedure. In the course of this work, a method of evaluating the available equipment was developed and this is described.     

High resolution scanning of DNA autoradiographs.

The sizes of DNA fragments (alleles) on autoradiographs are measured by means of a computerised video scanner developed in this laboratory. This report investigates the advantages of using higher resolution equipment for this purpose. High resolution is simulated by using existing equipment and moving the video camera closer to the autoradiograph. Test autoradiographs, used to validate the original scanner, have been rescanned to determine the degree of improvement that could be obtained using expensive high resolution equipment.     

A micro-computer system for potentiometric stripping analysis

In potentiometric stripping analysis, trace metals are first amalgamated into a mercury film electrode and then oxidized back into solution by an oxidant. The potential vs. time curve is recorded. Microcomputer-controlled equipment for automation of the potentiometric stripping analysis is described. The higher resolution of time compared to manual equipment increases the sensitivity of the method. A resident, 3-kB BASIC interpreter with routines for handling the hardware makes the programming simple and the instrumentation flexible for changes in the analytical scheme. Printer and keyboard are incorporated in the equipment which makes the whole analyser compact.     

Food processors requirements met by radiation processing

Processing food using irradiation provides significant advantages to food producers by destroying harmful pathogens and extending shelf life without any detectable physical or chemical changes. It is expected that through increased public education, food irradiation will emerge as a viable commercial industry. Food production in most countries involves state of the art manufacturing, packaging, labeling, and shipping techniques that provides maximum efficiency and profit. In the United States, food sales are extremely competitive and profit margins small. Most food producers have heavily invested in equipment and are hesitant to modify their equipment. Meat and poultry producers in particular utilize sophisticated production machinery that processes enormous volumes of product on a continuous basis. It is incumbent on the food irradiation equipment suppliers to develop equipment that can easily merge with existing processes without requiring major changes to either the final food product or the process utilized to produce that product. Before a food producer can include irradiation as part of their food production process, they must be certain the available equipment meets their needs. This paper will examine several major requirements of food processors that will most likely have to be provided by the supplier of the irradiation equipment.     

理化分析测试实验室仪器设备的管理

仪器设备是实验室的重要资产,仪器设备管理是实验室正常运行的重要组成部分。从仪器设备的管理架构以及仪器设备的采购、验收、量值溯源、维护维修、报废等方面讨论了理化分析测试实验室仪器设备管理工作的重点和注意事项。     

Cleaning validation using thermogravimetry

The health authorities require that equipment used in the pharmaceutical industry is clean prior to use. The main raison is to prevent any contamination of the drug products. This article demonstrates that thermogravimetry (TG) can be used for the determination of the residual impurities during the cleaning validation of the equipment of pharmaceutical production plants. The accuracy and the recovery rate of this method are comparable with those of the classical analysis method (determination of the distillation residue using a rotary evaporator). The fully automation of the testing equipment even allows its utilization around the clock by plants operators, leading to a significant reduction of the time necessary for the cleaning validation and to an increase of the plant capacity.     

Selecting parameters and limits for equipment operational qualification

While operational qualification (OQ) is a well-established term within equipment qualification, users of equipment often become unsure when it comes to implementation. The biggest problem is how to select procedures and acceptance criteria. Should these be the vendor's specifications or should the users define their own limits, and, if so, how? Should all instruments of the same type have the same values or should these be optimized for each individual instrument? This article will provide an overall strategy and specific examples for HPLC on how to select procedures and acceptance limits that are based on efficient use of resources, on practicality and on the intended use of the equipment.     

开放式大型仪器平台管理探索与实践

大型仪器设备是高校的重要资源,是教育教学与科学研究的重要支撑,探索高效便捷的大型仪器管理方式,提高仪器的使用率和使用价值是管理者的共同追求. 结合浙江大学高分子科学与工程学系实验中心平台的管理实践,探索了利用社交软件辅助开放式实验平台管理的方式,同时结合社交平台的辅助功能实现了实验平台优质、高效、便捷的管理,大大提升了仪器的使用率,提高了平台管理人员的工作效率.     

Theoretical aspects of a preparative continuous chromatograph

Summary Equipment which has been used or suggested for preparative scale chromatography is reviewed. Particular attention is paid to one form of equipment for continuous counter-current chromatography which employs a moving mechanical seal. The theoretical effects of practical operating conditions and the mode of operation of this equipment are discussed. The influence of these effects on polymer fractionation is also considered. A theoretical model, based on the equilibrium stage concept, is proposed for the simulation of continuous gel permeation chromatography of a binary feed on such an apparatus. Examples of the results obtained from the computer simulation are given.     

Heavy element chemistry facilities at Texas A&M University

A new program to study the chemistry of the homologs of the transactinide elements is under development, and is centered at the Texas A&M University Cyclotron Institute. New facilities have been designed and/or implemented to enable this research. These include equipment for the production of lanthanide and other targets, a rotating target wheel, an improved recoil transfer chamber, and a customized on-line radiochemical laboratory. Additional target development is being performed at Argonne National Laboratory. The new facilities and equipment are discussed.     

The elimination of the getter effect in the determination of gases in metals by the vacuum fusion method

A furnace for determinations of gases in metals is described in detail. The essential part of the equipment is the stopper, which acts as a non-gettering baffle as well as a splash shield. The stopper is constructed of two conical halves of graphite; the movement follows by means of a rotatable shaft, passing through the tube and sealed by rubber o-rings. The entire analytical equipment is outlined, and some results of analysis with and without the stopper are given.     

Excess volumes of propanol-water mixtures at 5, 15, and 25°C

This paper reports on equipment for the automatic measurement of the density of binary mixtures as a function of concentration. The equipment is applied to mixtures of 1-propanol and water at 5, 15, and 25°C. An equilibrium mixture model, in which an alcohol-water solution is regarded as an ideal associated mixture, is fitted to the experimental data. Thermodynamic parameters characterizing the association of water to nonpolar alkyl groups (hydrophobic solvation) and to polar hydroxyl groups (hydrophilic solvation) are estimated.     

Performance testing activities for analytical assessment of supercritical fluid extractors

Systematic performance testing activities for supercritical fluid extractors consistent with the implementation of quality systems in analytical laboratories are proposed. In this context, supercritical fluid extraction (SFE) is used for the automatic processing of complex samples. Ensuring reproducible operation of SFE equipment is crucial with a view to obtaining traceable results. To this end, an assessment protocol including recommended preventive and corrective actions, and complementary internal quality control activities, was developed with a view to facilitating the use of SFE equipment by routine analytical laboratories.     

The fluoride content of an anion exchange resin in the fluoride form. Determinations using18F as a tracer

The fluoride content of an anion exchange resin in the F⁻-form depends on the material of the equipment used for the preparation. If a glass equipment is used too much fluorine is introduced, but in a teflon equipment the fluoride content is exactly as expected. The experimental results are explained by taking into account a competition of F⁻ and SiF ₆ ⁻² for the hydroxyl positions of the resin(OH⁻).     

Application of ICP-MS radionuclide analysis to “Real World” samples of department of Energy radioactive waste

Germanium spectrometers must be operated at liquid nitrogen temperatures. Other detectors operate better when cooled. Many applications, because of hostile environments, inaccessibility, remote location, long duration, etc., are compromised, or totally precluded, by the requirement for liquid nitrogen. A Stirling cycle refrigerator based on a linear motor design, which is acoustically and vibrationally quiet, does not require secondary cooling, and operates unattended for years, is under development. System design and specifications are presented. Applications to cooled laser monitoring equipment. SQUID-based detection systems, environmental cleanup and monitoring, medical diagnostics, non-destructive testing systems, communication equipment, computer electronics, and imaging systems are discussed.     

Multielement standards for instrumental neutron activation analysis of biological materials

Standards for instrumental neutron activation analysis (INAA) of biological materials are proposed. The standards are multielement solid solutions in phenol-formaldehyde resole resin (PFR) moulded as pellets weighing 30 to 50 mg. The concentrations of trace elements in the standards are selected so that, firstly, they are commensurable with their concentrations in the biological materials and, secondly, that the analytical lines of each of the elements incorporated in PFR are resolved with the aid of modern equipment. The principal standard contains 21 trace elements from among those of greatest interest for INAA of biological materials. This standard is recommended for work on high-resolution equipment. At the same time, standards of simpler trace element composition have been prepared and studied which can be used in work on simpler equipment or in solving particular problems in determination of certain groups of chemical elements.     

Comparison of Overpressured-Layer Chromatography and High-Performance/High-Pressure Layer Electrochromatography Using the New Prototype Equipment in Various Operational Modes

In our previous paper we have presented the new prototype equipment and introduced a new analytical technique—high-performance/high-pressure layer electrochromatography (HPLEC), a combination of overpressured-layer chromatography (OPLC) and pressurized planar electrochromatography (PPEC). In this paper, the work of the equipment in various operational modes is investigated. Some difficulties and challenges related to various aspects of separation are discussed. The OPLC and HPLEC techniques are compared in terms of selectivity and performance. The results show that our equipment can be successfully used for singe- and multichannel OPLC and HPLEC separations in various sample application and detection modes. It includes the high-throughput, multichannel, and fully automated online separation of multiple samples simultaneously. The equipment allows for the independent optimization of various operational parameters. HPLEC combines the advantages of column/capillary and planar separation techniques while overcoming their limitations. It also combines the advantages and overcomes the drawbacks of OPLC and PPEC. It provides hydrodynamic flow of the mobile phase, irrespective of the voltage used and/or the mobile phase composition. Thus, any optimization of the composition and the voltage can be used independently. Both can be used to obtain the required selectivity of separation. The voltage can be used to facilitate the mobile phase flow and accelerate the analysis.     

Automated instrumentation for miniaturized displacement electrophoresis with on-column photometric detection

This paper describes an automated equipment for capillary displacement electrophoresis (isotachophoresis). The equipment employs the advantages of a separation channel with a nonuniform cross-section. The system works in a closed mode, the analytes are determined as anions in the examined arrangement. The pH gradient is within the range 4.4–11.0, the total voltage over the separation channel is from 150 V to 900 V at a constant current of 20 μA or 10 μA, respectively. Cetyltrimethylammoniumbromide and either hydroxypropylcellulose or hydroxypropylmethylcellulose are used in the leading electrolyte to control the electroosmotic flow.

The reproducibility and the minimum detectable concentrations are determined and calibration curves are measured using a model mixture of p1 markers and myoglobin as analytes and either low-molecular-mass ampholytec buffers or synthetic carrier ampholytes as spacers. Both Gaussian peaks and the square-wave zones were evaluated.