Chemical Testing Laboratories Research Articles

Research on the Application of Information Management System in the Laboratory of Power Generation Enterprises

Information management systems have achieved many application results in the management of metrological calibration and chemical testing laboratories facing society, but there are few research and application cases that combine the two information systems. The power generation enterprise is equipped with both a metrological calibration laboratory and a chemical testing laboratory. Huadian Laizhou Power Generation Co., Ltd. and Huadian Electric Power Research Institute Co., Ltd. have jointly developed an information system that can manage both laboratory businesses simultaneously. Starting from practical cases, this article discusses the development feasibility of this information system, its differences from conventional laboratory information systems, and the innovation points implemented in the project from the perspectives of information technology and software function settings.

Matrix Reference Materials Development for Food Safety Application in Philippine Products

<p>The development of RMs was pioneered in the Philippines by the Industrial Technology Development Institute (ITDI) - DOST as part of its vision to establish metrological traceability and support the RMs needs of chemical testing laboratories in the country. Food safety issues for chemical testing of Philippine products were prioritized in this activity as these could affect the health of consumers and trade issues. Reference methods used for the provision of reference value was developed and validated for contaminants like histamine and benzoic acid in canned tuna and mango juice respectively. The materials were prepared and characterized and found to be homogeneous and stable for at least six (6) months. The reference value assigned to these RMs was done using a higher order method like isotope dilution technique coupled with Liquid Chromatography-Triple Quadrupole Mass Spectrometry (LCMSMS). Results were also cross-checked using gravimetric technique for High Performance Liquid Chromatography (HPLC) analysis. Certified RMs purchased from Metrology Institutes were also used to further support traceability of measurements. Philippine product RMs were developed for histamine and benzoic acid. The measurement traceability was disseminated by ITDI to local testing laboratories through the Proficiency Test schemes organized and conducted for the said analytes. </p>

Design and Development of Arsenic and Iron Removal Unit for Drinking Water: A Sustainable Approach in Environment

This study elucidated and attempted to design and development of arsenic and iron removal unit for drinking water. The process of reducing iron and arsenic from water has been experimented by developing a unit in the Department of Farm Structure at Bangladesh Agriculture University, Mymensingh. In order to test the performance of the developed unit, arsenic contaminated water with four different concentrations like 0.05, 0.10, 0.15 and 0.20 mg/l were prepared in the laboratory and passed into the developed unit and the respective output concentrations were found to be 0.00, 0.01, 0.025 and 0.05 mg/l. The input and output concentrations of arsenic were tested in the chemical testing laboratory under the Bangladesh Institute of Nuclear Agriculture, Mymensingh. Iron contaminated water were collected from four selected tube wells of local Mymensingh and were also passed into the developed unit with four input concentrations like 0.18, 0.1532, 0.179 and 0.133 mg/l and the respective output concentrations were found to be 0.10, 0.1021, 0.11 and 0.09 mg/l. The concentrations of Iron were tested in the chemical testing laboratory under the Soil Resource Development Institute, Dhaka. The results have revealed that iron and arsenic content brings to allowable limit. The developed unit has the capacity to remove Arsenic and Iron and help to eradicates hazardous problem of people.

Development of melamine certified reference material in milk using two different isotope dilution mass spectrometry techniques

A new certified reference material (CRM) of melamine in milk GLHK-11-02 was developed aiming to address the great demand from the testing community after the melamine crises. The material was prepared by adding an appropriate quantity of melamine into the skimmed milk samples and the final product was in the form of fine lyophilized powder. Characterization of the material relied on two newly developed gravimetric isotope dilution mass spectrometry (IDMS) methods, one using liquid chromatography–tandem mass spectrometry (LC–MS/MS) and another gas chromatography–mass spectrometry (GC–MS). Experimental parameters with crucial effects on the performance of the two IDMS methods were thoroughly investigated. These included purity of standard used, equilibration time of isotopes, efficiency of extraction methods as well as possible interferences from the matrix and melamine analogues. Precision was found to be excellent with a coefficient of variation of 2.5% for the LC–IDMS/MS ( n = 46) and 1.9% for the GC–IDMS ( n = 30) respectively. Using one-tail Student's t-test at 95% confidence interval, analytical data sets generated from the two methods were found to exhibit no significant difference. Measurement accuracy of the methods was further verified through an Asia Pacific Metrology Program (APMP) pilot study. Analytical results of the present LC–IDMS/MS for the two milk test samples at the concentration level of about 0.45 and 3.5 mg kg −1 were proven to be very good. There were excellent overlaps between our results and the assigned reference values, and the absolute deviation was less than 3.2%. Both the LC–IDMS/MS and GC–IDMS methods were shown to be sufficiently reliable and accurate for certification of the melamine CRM. Certified value of melamine in dry mass fraction in GLHK-11-02 was 1.14 mg kg −1. Expanded uncertainty due to sample inhomogeneity, long term and short term stability and variability in the characterization procedure was at 7.1% or 0.08 mg kg −1. The CRM is primarily used to provide a complete method validation for and to improve the technical competence of melamine analysis to food and chemical testing laboratories.

Initiatives of the Australasian Soil and Plant Analysis Council to Assess the Measurement Quality of Common Methods for Soil and Plant Analysis in Australasia

The Australasian Soil and Plant Analysis Council Inc (ASPAC) commenced its not‐for‐profit interlaboratory proficiency programs (ILPPs) in 1990 and issued its first soil program report in 1993. ILPPs target soil and plant chemical testing laboratories across Australasia. These ILPPs contribute to ASPAC's goals to promote excellence in all aspects of soil and plant analysis and to encourage adoption of preferred methods and protocols used in soil and plant analysis within Australasia. The ASPAC recently re‐engineered its ILPPs to increase both their frequency and the number of samples assessed in a program year, the first of which was completed in 2004–5. This article provides more details on these new ILLPs for soils and plants, including how ASPAC's method‐specific certification now operates. More than 35 laboratories undertake the most popular soil tests but less than half report results for more specialized or less common tests. Also included is an outline of comparative results from a pilot assessment of Mehlich 3 soil‐test parameters using four homogeneous samples (and results) obtained from the North American ILPP. For the most part, results were wider apart than expected, which may be confounded by storage and handling changes in the samples that also had to pass strict quarantine protocols in Australia and New Zealand. The ILPPs of ASPAC are overseen by ASPAC's Laboratory Proficiency Committee, comprised of a convenor and three others. A Technical Advisory Group operates between ASPAC and its proficiency service provider, who is now located in New Zealand.

Practical aspects of the uncertainty and traceability of spectrochemical measurement results by electrothermal atomic absorption spectrometry

The determination of trace elements concentration in water by electrothermal atomic absorption spectrometry (ETAAS) is a common and well established technique in many chemical testing laboratories. However, the evaluation of measurement uncertainty results is not systematically implemented. The paper presents an easy step-by-step example leading to the evaluation of the combined standard uncertainty of copper determination in water using ETAAS. The major contributors to the overall measurement uncertainty are identified due to amount of copper in water sample that mainly depends on the absorbance measurements, due to certified reference material and due to auto-sampler volume measurements. The practical aspects how the traceability of copper concentration in water can be established and demonstrated are also pointed out.

Estimating measurement uncertainty in an afternoon. A case study in the practical application of measurement uncertainty

The ISO/IEC 17025:1999 standard requires chemical testing laboratories to have an estimate of the uncertainty of their measurements. This is a new requirement for many laboratories and there is confusion as to how to estimate uncertainty. Concerns have been raised about the time and effort required to obtain uncertainty estimates.

Capacity planning with congestion effects

Important operational performance measures for a successful firm include not only price and quality, but also fast and on time delivery of customer orders. Capacity is a key issue in determining the lead time from customer order to delivery. However, capacity planning models seldom consider the impact of capacity levels on lead time performance. An important characteristic of this paper is the incorporation of congestion effects and their impact on lead time in making capacity acquisition decisions. It is especially important in a make-to-order environment, where customer orders arrive randomly and lead to high variability and congestion. This work was motivated by our observations of such tradeoffs at firms in several industries. We present a model to make equipment choice decisions in a multi-product, multi-machine, and single-stage production environment with congestion effects. The model is a nonlinear integer program. We present a heuristic solution procedure for this problem, which is based on a lower bound for the formulation that can be solved efficiently. The computational study shows that the solution procedure is quite effective in solving industry size problems. We illustrate the application of the model using data from a chemical-testing laboratory. We also discuss various extensions of the model.

Abnormally high fluoride levels in commercial preparations of 40 per cent silver fluoride solution: contraindications for use in children.

Although a 40 per cent solution of silver fluoride would be expected to contain 6 per cent fluoride (60,000 ppm), F-levels of 100,000 ppm and 120,000 ppm were found in 14 commercial samples analysed at The University of Western Australia in 1993 and 1994. To determine whether F-levels in 40 per cent AgF preparations have remained high, the present investigation was aimed at analysing different batches of commercial preparations obtained more recently. Fluoride ion analysis was carried out on 24 AgF samples using the Ion-Selective Electrode technique. Independent analyses of the same samples were carried out by a private chemical testing laboratory (Genalysis). Ten samples supplied by Agson Chemical Export were found to contain between 75,000 and 100,000 ppm F-: Genalysis reported 80,000 to 120,000 ppm. Fourteen samples supplied by Southern Dental Industries were found to contain between 70,000 and 120,000 ppm F-; Genalysis reported 88,000 to 108,000 ppm F-. These results confirm significantly higher than expected F-levels (ANOVA p < 0.05) in commercial preparations of 40 per cent AgF. The solutions tested were found to contain a mixture of ammonium fluoride, sodium or potassium fluoride, and silver fluoride. The additional presence of silver difluoride and hydrofluoric acid resulting from the manufacturing process has been suggested as an explanation for the much higher than expected levels of fluoride ion. In view of possible toxicity of 40 per cent AgF in young children, it is concluded that such a highly concentrated solution should not be used clinically; instead, lower strength AgF solutions should be investigated for their efficacy in caries treatment.

97/04257 Development of the quality assurance system and accreditation of the chemical testing laboratory of the Austrian Draukraftwerke Power Plant Works

97/04257 Development of the quality assurance system and accreditation of the chemical testing laboratory of the Austrian Draukraftwerke Power Plant Works

A production planning and scheduling system at a chemical testing laboratory

There has been much interest recently in production scheduling models, where batching and sequencing issues are considered simultaneously. In this paper, we describe the development of a production planning and scheduling system in a surprisingly complicated production environment, a chemical testing laboratory. The process for testing water and soil samples in this laboratory consists of an instrument analysis stage, wherein both batching and sequencing issues must be addressed. The production control system we developed to help manage it consists of a capacity allocation module, a batching and sequencing module, a detailed sample scheduling module and various databases. We also developed a simple formula to dynamically determine batch sizes using a resource pricing approach and a priority rule to sequence these batches. The batching and sequencing procedure based on these ideas was evaluated against two alternative heuristic procedures on many randomly generated problems and was shown to perform very well. This paper describes the details of the production process, the characteristics of the new production control system, the development of the batching and sequencing heuristic and some directions for future research.

Characteristics and capabilities of U. S. commercial toxicological testing laboratories

About 800 commerical chemical testing laboratories were surveyed by telephone to determine how many provide toxicological testing services and what characteristics the toxicological testing laboratories portrayed. The survey identified 274 laboratories that performed toxicological testing in 1981. These are estimated to account for 94 to 98% of the toxicology laboratory population. The survey data provided a general profile of these laboratories, showed the number of laboratories capable of performing different types of tests, indicated the amount of excess capacity, and identified the most critical constraints to future expansion of testing. There were an estimated 180 laboratories providing mammalian toxicological tests, 150 providing in vitro tests, 150 providing environmental effects tests, and 140 providing chemical fate tests. At the time of the survey, the industry appeared able to do about 20% additional testing before reaching capacity.