• Bulletin of the Korean Chemical Society
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• v.33 no.10
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• pp.3485-3488
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• 2012

• Analytical Science and Technology
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• v.26 no.1
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• pp.91-98
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• 2013

Interested in NOA (Naturally Occurring Asbestos), Korea as well as the USA has been making geologic maps of asbestos distributed mines and surrounding areas, restoring mines, evaluating hazard, and so on. The result can be used to improve the reliability of analysts and analysis institutions by judging the amount of asbestos and set up PLM(Polarizing Light Microscope) information by analyzing in soil. The certification value of 2 kinds of CRM(Certified Reference Material) was performed by counting total 400 points with EPA 600-R-93-116 method using by PLM. The following is the result of homogeneity and stability of 2 kinds of manufactured CRM analyzed by ANOVA (Analysis of variance) and Regression Analysis. Based on the analyzation, the results are satisfied with homogeneity and long-term stability. The analyzed certification value of CRM includes the range of minimum and maximum value of point counting result for chrysotile; low concentration-1% (range, 0.25~3.00), high concentration-4% (range, 2.25~5.50).

• Analytical Science and Technology
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• v.24 no.6
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• pp.503-509
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• 2011

Specific surface area is becoming a very important factor when newly developed advanced nano-materials are evaluated. But there have been many differences in results when measuring specific surface areas, depending on the measuring equipments and analysis method. To verify the reliability of the specific surface area measurement device supplied within the country, Round Robin Test (RRT) has been done at 21 affiliated research institutes. As a result, it was found that several institute had problems in measuring of gas adsorption amount in measuring equipment, and this proved the need for certified reference material (CRM). Furthermore, it was also found that the results from BET analysis is easily swayed by the analyst's subjectivism, and the calculated results may differ up to 16% in case of CRM I depending on the selection range of BET analysis. So this showed that a standard guideline for BET constant C value and fitting correlation coefficient R is needed, to properly select range in BET analysis. The experience in RRT, distribution of CRM, and standardized procedure would result in improved reliability in industrial processes, and thus, would contribute to the quality management, the productivity improvement, the safety evaluation, and the new material development.

• Mass Spectrometry Letters
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• v.14 no.4
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• pp.166-172
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• 2023

The utilization of methyl 2-aminobenzoate as a biocide and pesticide has raised concerns regarding its potential toxicity. To assess its safety, it is crucial to determine its quantity and related toxicity using reference materials (RMs) or certified reference materials (CRMs). As an RM and CRM containing methyl 2-aminobenzoate within a biocidal product matrix is currently unavailable, this study aimed to produce a high-quality RM containing methyl 2-aminobenzoate, ensuring its homogeneity and stability, following the ISO Guide 35 and ISO 17034. The study determined that the produced RM exhibited homogeneity, as indicated by a calculated F-value (1.91) smaller than the critical F-value (3.02). In the assessment of isochronous short-term stability, the slope of the linear regression for the RM showed no statistically significant difference from zero when stored at temperatures of 4, 18, and 60 ℃ for 4 weeks. Regarding classical long-term stability, the RM demonstrated sustained stability over the course of one year when stored at 4 ℃. This study has successfully developed an RM for monitoring methyl 2-aminobenzoate in biocides and pesticides. Its quality underwent rigorous evaluation, confirming both homogeneity and stability.

• Analytical Science and Technology
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• v.23 no.5
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• pp.485-491
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• 2010

A certified reference material (CRM) of KRISS 109-03-SSD was developed for the analysis of hazardous elements in soil. The target elements were As, Cd, Cr, Cu, Hg, Ni, Pb, Zn being regulated by the Soil Environment Conservation Act. Starting material was collected from tailing dump of an unworked tungsten mine at Sangdong (Gangwon-do, Korea). The starting material under-went through a series of fabricating process steps of screening, drying, grinding, sieving, blending, bottling, sterilization and was certified according to the ISO Guide 35. Isotope dilution-inductively coupled mass spectrometry (ID-ICP/MS) and instrumental neutron activation analysis (INAA) were used for the measurement. Homogeneity was tested according to ISO 13528 annex B. The certified values were determined using the results from two different methods or from two independent measurements using a method. Finally, certified values of seven elements of arsenic, cadmium, chromium, copper, lead, nickel and zinc were determined. Mercury did not satisfied the criteria of homogeneity and the result would be provided for information only, together with iron and tungsten. It was also studied, the extractable fraction of elements by aqua regia according to the ISO 11466 protocol being frequently studied for the purpose of environmental monitoring. It was performed as a inter-laboratory study by 6 laboratories of a public institute and universities. Standard deviation among the laboratories was much bigger than the uncertainty of the certified value. The result of inter-laboratory study on the extractable fraction will be provided for information, only.

• Analytical Science and Technology
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• v.35 no.6
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• pp.249-255
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• 2022

In this study, a new method for the analysis of high-purity nitrogen was developed. A gas chromatography-flame ionization detector (GC-FID) was used for purity analysis. Certified reference materials (CRMs) at a level of 3 µmol/mol of carbon monoxide (CO), carbon dioxide (CO₂), and methane (CH₄), which may exist in high-purity nitrogen, were prepared using the gravimetric method, and these CRMs were used for purity analysis. In this new method, ultra-high-purity and high-purity nitrogen were used as carrier gases. The impurities in high-purity nitrogen were quantitatively analyzed by comparing the differences in the area values of the GC chromatograms of the prepared CRMs. We purchased liquid nitrogen and three bottles of nitrogen gas, which were produced by three different manufacturers, using high-purity nitrogen. Furthermore, to validate the developed purity analysis method, the fraction of impurities in high-purity nitrogen was compared with the results of the typical purity analysis method. The comparison results were consistent within the expanded uncertainties (k = 2).

• Analytical Science and Technology
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• v.18 no.1
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• pp.74-84
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• 2005

Understandings of adsorption characteristic of interface are very important in several advanced materials processes, related to NT and BT technology. Volumetric gas adsorption method, suitable for absolute measurements, is regarded as the standardized measurement technique for specific surface area. In order to verify the reliability of commercial equipments, certified reference materials (called CRM) of specific surface area are developed and evaluated its uncertainty factors by standard equipment which has traceability to SI units. Specific surface areas of developed materials are $10.72{\pm}0.46m^2g^{-1}$ for silicon nitride powders and $149.50{\pm}3.44m^2g^{-1}$ for alumina. These disseminations of CRMs would result in improved reliability chains in industrial processes, and lead eventually to contribution to productivity improvement, quality management, safety evaluation, and possibly to new material development.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.21 no.2
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• pp.78-90
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• 2016

This report is to introduce detail processes during the restoration/revision project for the Korean Standard Methods for Marine Environment. The processes are composed of 3 steps: questionaries, QA/QC confirming step by CRM(Certified Reference Materials), and advisory council by specialists. The questionaries required four main topics to be included to the restoration/revision protocol: 1. the guidelines to sampling, transportation, storage, and pre-analytical procedures for the marine specimens, 2. the unified analytical method, especially for the organic compounds, 3. the QA/QC test requirement for CRM, 4. introduction of diverse analytical instruments, 5. the customer- friendly express of the protocol. Based on these new protocol, we expect two most important effects: 1, increased insurance of international credibility and equivalence by the QA/QC procedures, 2. increased conformability and representatively from wide-spread use of the protocol. Finally we suggested several residual topics remained to the inter-government cooperation.

• Analytical Science and Technology
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• v.26 no.5
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• pp.307-314
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• 2013

Selenium exists in various forms of chemical species. The activity and bioavailability is strongly dependent on its chemical form and concentration. Consequently the information on each selenium species and its concentration must be exactly determined for the food we take in. In this study, selenium species in seafood were separated and quantified by RP (reversed phase) HPLC (high performance liquid chromatography) coupled with ICP-MS (inductively coupled plasma mass spectrometry) using post-column isotope dilution. $^{79}Br$, which interferes on $^{80}Se$, has mostly been removed by solid phase extraction and then mathematical correction has been applied for the more accurate correction. The experimental result for CRM (certified reference material) DOLT-4 agreed well with the certified value but each selenium species could not be compared. SeCys (selenocysteine) and SeMet (selenomethionine) were the major species detected in seafood such as belt fish, spanish mackerel, and squid that have been serving as Korean diet. The concentrations found in Korean sea food for SeCys and SeMet were in the range of 0-661.6 mg/kg and 137.3-462.7 mg/kg, respectively.

• Korean Journal of Food Science and Technology
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• v.36 no.2
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• pp.189-195
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• 2004

Rapid and simple method was developed for simultaneous determination of vitamins A and E contents in infant formula. Vitamins A and E were extracted by PDA-HPLC with reversed phase column using organic solvent, and their contents in Certified Reference Material (CRM) and infant formula were determined and compared with results of Food Standards Codex and AOAC method for evaluation of developed method, Vitamins A and E contents in CRM determined by developed method were within certified range of standard values. Developed method has great advantages of simple and rapid sample preparation and simultaneous determination of vitamins A and E by PDA-HPLC using reversed phase column.