• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.30 no.1
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• pp.58-66
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• 2020

Objectives: The objective of this study was to develop formaldehyde samples for quality control (QC) and to test the applicability of proficiency analytical testing in Korea. Methods: We made formaldehyde samples with certified standard solutions (formaldehyde in water or acetonitrile) and 2,4-dinitrophenylhydrazine (2,4-DNPH)-coated silicagel tubes. Four levels of formaldehyde concentration were tested for storage stability at room temperature and at 4℃ over three months. Analytical proficiency testing was performed with four or 36 institutes. Results: Formaldehyde sample tubes were easily made through the injection of standard solutions and the average efficiencies of recovery were 95-101%. The coefficients of variation (CV) of the formaldehyde samples were 1.39-2.55%. The recovery efficiencies fell between 90% and 110% at the concentration range of 1-10 ㎍/sample over three months storage at refrigerated and room temperature. The CVs were less than 5% in the proficiency analytical testing. By adjusted proficient ranges, 64% of the results of the second proficiency analytical testing were acceptable. Conclusions: The formaldehyde samples made by injection on 2,4-DNPH-coated silicagel tubes were stable and applicable for quality control.

• Analytical Science and Technology
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• v.13 no.2
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• pp.229-233
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• 2000

The study was carried out to confirm the reliability of standard samples, low concentration $0.74mgN(NO_3)/l$, $0.58mgF^-/l$, high concentration $2.14mgN(NO_3)/l$, $1.25mgF^-/l$, on the base of quality control chart. The analytical results had the precise reliability with standard deviation of 0.010, 0.017, 0.056 and 0.019, respectively. When three persons A, B and C, who had different analytical experiences, analyzed the standard samples six times repeatedly, C person, who had more academic career and analytical experience, produced far better reliability for analytical results. Therefore, these standard samples were very suitable for external quality control test, because all persons' average values for analytical results were close to the values of prepared standard samples.

• Analytical Science and Technology
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• v.22 no.1
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• pp.35-43
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• 2009

The goal of PAT (Process Analytical Technology) is to build quality into products through better understanding and control of manufacturing processes, rather than merely testing the quality of the end product. Pharmaceutical manufacturers are trying to develop and implement new technologies in pharmaceutical production and quality control for real-time measurements of critical product and process parameters. Characterization of manufacturing process through experimental design, for evaluation of the effect of product and process variables, represents an integral part of the PAT framework. However, the publications regarding real PAT application to pharmaceutical process are very limited and the technologies are confidential as well. In this review, the case studies related to PAT are shown with real applications from a pharmaceutical company. Additionally, various applications of PAT on the developing stage are introduced with high analytical technologies for the improvement of quality control on manufacturing process.

• Journal of Physiology & Pathology in Korean Medicine
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• v.30 no.6
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• pp.397-401
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• 2016

The quality control is a fundamental procedure for the standardization of herbal medicine to guarantee the consistency of efficacy and safety. For a long time, the quality analysis of herbal medicine has been largely dependent on the routine sensory evaluation, such as taste, smell, color, and shape. However, with the recent development of analytical instruments, various scientific approaches have been introduced in this field. On the basis of the theory that the biological activities of herbal medicine are mainly contributed by its chemical compositions, several types of chemical markers have been suggested for the quality evaluation. In addition to the analytical methods for the specific marker compound(s), including analytical marker and active marker, recently, chemical fingerprinting, a method comparing the chromatographic pattern of the whole chemical components, has been developed and widely accepted as a reliable approach for the quality control of herbal medicine. Moreover, in order to exactly understand the relationship between complex compounds and their holistic biological activities in herbal medicine, unique strategies, such as "BECCs (bioactive equivalent combinatorial components)" and "PhytomicsQC" have been established. In this article, we give an overview of the several categories of chemical markers and the recent research trends for the quality evaluation of herbal medicine.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.3 no.2
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• pp.194-203
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• 1993

Quality Control programs for industrial hygiene laboratory have successfully been operated since the 1st round was initiated in April 1992. Three rounds have been completed. Overall analytical performance of participants was improved through a subsquent round. The first round had a large variation among analytical results of all participants, 26.34%~504.22% of coefficient of variation. But the variation of analytical performance in the 2nd and 3rd rounds decreased to 40.42%~52.55% and 10.74%~20.98%, respectively. The difference of analytical performance among participants was decreased by operation of subsquent round. By distribution of Running Performance Index (RPI), over 50% of participants belongs to Category 3 in the first round. The average percentage of participants assigned to Category 3 in the 2nd and 3rd round was decreased to 37.2%. A definite analytical performance improvement of participants seems to be obtained. "A" and "B" group have more participants assigned to Category 3 than those of "C" group through the distribution of RPI by group divided to similar participant. By the distribution of RPI all participants, the percent of participant being over 200 RPI in the 1st round was 43%~52%, but decreased to 9%~29% and 9%~27%, in the 2nd and 3rd round, respectively. These results mentioned above indicate that the analytical performance of all participants have been improved by subsquent Quality Control Program although newcomers joined and a few participants droped out. But, there are some participants with poor analytical performance. Industrial Health Research Institute (IHRI) will offer service such as education, communication and visitation to them, and improve quality of their analytical performance in the future.

• Analytical Science and Technology
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• v.12 no.4
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• pp.346-353
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• 1999

For the non-destructive multi-elemental analysis of environmental and biological materials, instrumental neutron activation analysis (INAA) was applied for the determination of toxic and trace elements in a set of three Algae samples provided by the International Atomic Energy Agency (IAEA). The analytical quality control was evaluated by comparing the analytical results of two standard reference materials of the National Institute of Standards and Technology (NIST); Oyster Tissue (SRM 1566a) and Citrus Leaves (SRM 1572). According to given analytical procedure, the concentration of 15-25 elements including spiked elements such as As, Cd, Cr and Hg in Algae samples were determined. To identify and validate these results, a data intercomparison program using more than 35 analytical methods in 150 laboratories was carried out and the estimated statistical data are summarized. Result of INAA is favorable, therefore, it is illustrated that can be applied for routine analysis of essential and toxic elements in algae samples as well as analytical quality assurance.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.19 no.2
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• pp.81-87
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• 2009

Final purpose of this study was designed to develop the quality control(QC) sample for proficiency analytical testing of asbestos. This study consisted of two parts; first, development of manufacturing apparatus and sample preparing procedure for asbestos quality control(QC) sample: second, validation of the QC samples made by our developed method as asbestos proficiency analytical testing sample. The main results of the first part research are as followed We developed the apparatus for manufacturing the asbestos QC sample, consisted of filter hold, filter holder manifolder, vacuum system, and vacuum pump. The most proper filter of making the QC samples was a cellulose ester membrane filter with 25 mm diameter, pore size 0.8 um. And we presented the optimal procedure for preparing the asbestos QC sample by using the developed apparatus. We will verify the manufactured asbestos QC samples by this method, and present the validation results to confirm the reliability as a asbestos QC sample in next paper.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.23 no.3
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• pp.243-249
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• 2013

Objectives: This study assessed the status of domestic industrial hygiene laboratories using data from on-site investigation for revision of quality control systems in 2012-2013. Methods: The target laboratories were 60 industrial hygiene laboratories chosen by random selection and nationwide distribution which had participated in on-site investigations for revision of quality control systems from March 2012 to August 2013. The investigation was performed on-site following standard quality control procedures. The score between each group was compared using Mann-Whitney and Kruskal-Wallis tests, and the correlation between analytical career, sex, academic major of analyst and score of analytical performance was expressed as Spearman's rank correlation coefficient. Results: The assessment revealed that the items to be improved, in sequence, were effort at staff training (score 65.5), ability to calculate data (score 73.4), establishment of internal quality control guidelines (score 75.7), laboratory facilities (score 77.1), degree of understanding and skill at gas chromatography (score 77.1). Analysis performance showed a positive correlation with career of analyst (r=0.56, p<0.01). Conclusions: The practice of on-site investigation for quality control systems showed the current status of industrial hygiene laboratories in the first trial. There were many laboratories which needed improvement and development of analytical systems. This assessment can provide information for the systematic operation and improvement of facilities at each laboratory. Further practice of this investigation will lead to a proficiency testing and accreditation system for autonomous quality control as is the practice in many countries, rather than mandatory practice by legal regulation.

• Analytical Science and Technology
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• v.8 no.4
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• pp.1079-1087
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• 1995

The quality of human life is directly related to the quality of the environment. To assess environmental quality we must first determine the MCLG(Maximum Contaminant Level Goal), MCL(Maximum Contaminant Level), environmental impact and so on. The MCLG is the concentration at which no known adverse health effects occur. The MCLG is determined by risk assessment identifying which process is hazardous assessing, dose-response, human exposure, and characteristics of risk. With consideration of analytical methods, treatment technology, cost and regulatory impact, the MCL is set as close to the MCLG as possible. In this way, determination of the concentration and national distribution of contaminants is important for assessment of environmental quality The analytical sciences pose potential problems in assessing environmental quality. Continuing improvement in the performance of analytical instruments and operating technique has been lowering the limits of detectability. Contaminant concentration below the detection limit has usually been reported as ND(Not-Detected) and this has often been misunderstood as equivalent to zero. Because of this, more the contaminant concentration in the past was below the detection limit, whereas contaminants can be quantified now even though the contaminant concentration might remain the same or may even have decreased. In addition, environmental sampling has various components due to heterogeneous matrices. These samples are used to overestimate the concentration of the contaminant due to large variability, resulting in excess readings for MCL. In this paper, the significance of the analytical sciences is emphasized in both a conceptual and a technical approach to environmental assessment.

• Analytical Science and Technology
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• v.9 no.4
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• pp.1110-1124
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• 1996