• Analytical Science and Technology
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• v.23 no.1
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• pp.1-14
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• 2010

It is of importance that all countries in worldwide, including EU and China, have adopted the Restrictions on the use of certain Hazardous Substances (RoHS) for all electronics. IEC62321 document, which was published by the International Electronics Committee (IEC) can have conflicts with the standards in the market. On the contrary Publicly Accessible Specification (PAS) for sampling published by IEC TC111 can be adopted for complementary application. In this work, we tried to find a route to disassemble and disjoint cellular phone sample, based on PAS and compare the screening methods available in the market. For this work, the cellular phone produced in 2001, before the regulation was born, was chosen for better detection. Although X-ray Fluorescence (XRF) showed excellent performance for screening, fast and easy handling, it can give information on the surface, not the bulk, and have some limitations due to significant matrix interference and lack of variety of standards for quantification. It means that screening with XRF sometimes requires supplementary tool. There are several techniques available in the market of analytical instruments. Laser ablation (LA) ICP-MS, energy dispersive (ED) XRF and scanning electron microscope (SEM)-energy dispersive X-ray (EDX) were demonstrated for screening a cellular phone. For quantitative determination, graphite furnace atomic absorption spectrometry (GF-AAS) was employed. Experimental results for Pb in a battery showed large difference in analytical results in between XRF and GF-AAS, i.e., 0.92% and 5.67%, respectively. In addition, the standard deviation of XRF was extremely large in the range of 23-168%, compared with that in the range of 1.9-92.3% for LA-ICP-MS. In conclusion, GF-AAS was required for quantitative analysis although EDX was used for screening. In this work, it was proved that LA-ICP-MS can be used as a screening method for fast analysis to determine hazardous elements in electrical products.

• Journal of Sericultural and Entomological Science
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• v.46 no.2
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• pp.47-53
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• 2004

To reveal the possibility as a source of functional food and to increase the usability of mulberry fruits, amino acid analysis with mulberry fruits was carried out with L-8800 Amino acid auto analyzer. We analyzed 16 amino acid components including 6 essential amino acids. According to the results, the mean content of total amino acid was 4,640.8 mg/100 g DW. 'Sabangso(II)' showed the highest total amino acid content (6,919.3 mg/100 g DW) among the fifty accessions tested, whereas 'Gukkwang' showed the lowest content (3,389.1 mg/100 g DW). The distribution rate of amino acid components decreased in the order of Glu ($20.1\%$) > Gly ($12.7\%$) > Asp ($12.5\%$) > Thr ($8.2\%$) > Ala ($7.9\%$) > Arg ($7.5\%$) > Pro ($6.1\%$) > Ser ($6.1\%$) > Val ($5.7\%$) > Leu ($5.3\%$) > Ile ($2.7\%$) > His ($2.5\%$) > Met ($0.9\%$) > Tyr ($0.8\%$) > Lys ($0.7\%$) > Cys ($0.3\%$). 'Sabangso(II)' showed the highest content in 11 amino acid components, which were Glu (1,293.2 mg/100 g), Ser (390.2 mg/100 g), Thr (564.4 mg/100 g), His (175.3 mg/100 g), Arg (590.4 mg/100 g), Lys (53.5 mg/100 g), Gly (589.4 mg/100 g), Ala (499.3 mg/100 g), Leu (481.9 mg/100 g), Ile (240.9 mg/100 g), and Val (407.6 mg/100 g). Tyr and Cys were the highest in 'Jangsosang' (70.8 mg/100 g, 19.3 mg/100 g, respectively), and Asp, Pro, and Met were the highest in 'Jasan(I)', 'Hwansipchosaeng' and 'Palcheongsipyung(I)' (1,098.8 mg/100 g, 364.4 mg/100 g, 68.8 mg/100 g, respectively).

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.2
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• pp.210-219
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• 2017

This study aimed to establish an optimal extraction process and high-performance liquid chromatography (HPLC)-photodiode array (PDA) analytical method for determination of marker compounds, dihydrokaempferol (DHK) and 3-O-methylquercetin (3-MeQ), as a part of materials standardization for the development of health functional foods from stems of Opuntia ficus-indica var. saboten (OFS). The quantitative determination method of marker compounds was optimized by HPLC analysis, and the correlation coefficient for the calibration curve showed very good linearity. The HPLC-PDA method was applied successfully to quantification of marker compounds in OFS after validation of the method in terms of linearity, accuracy, and precision. Ethanolic extracts from stems of O. ficus-indica var. saboten (OFSEs) were evaluated by reflux extraction at 70 and $80^{\circ}C$ with 50, 70, and 80% ethanol for 3, 4, 5, and 6 h. Among OFSEs, OFS70E at $80^{\circ}C$ showed the highest contents of DHK and 3-MeQ of $26.42{\pm}0.65$ and $3.88{\pm}0.29mg/OFS100g$, respectively. Furthermore, OFSEs were determined for their antioxidant activities by measuring 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging and lipid peroxidation (LPO) inhibitory activities in rat liver homogenate. OFS70E at $70^{\circ}C$ showed the most potent antioxidant activities with $IC_{50}$ values of $1.19{\pm}0.11$ and $0.89{\pm}0.09mg/mL$ in the DPPH radical scavenging and LPO inhibitory assays, respectively. To identify active components of OFS, various chromatographic separation of OFS70E led to isolation of 11 flavonoids: dihydrokaempferol, dihydroquercetin, 3-O-methylquercetin, quercetin, isorhamnetin 3-O-glucoside, isorhamnetin 3-O-galactoside, narcissin, kaempferol 7-O-glucoside, quercetin 3-O-galactoside, isorhamnetin, and kaempferol 3-O-rutinoside. The results suggest that standardization of DHK in OFSEs using HPLC-PDA analysis would be an acceptable method for the development of health functional foods.

• Journal of Food Hygiene and Safety
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• v.26 no.2
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• pp.142-149
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• 2011

An isocratic high performance liquid chromatography (HPLC) method for routine analysis of deoxynivalenol in noodles was validated and estimated the measurement uncertainty. Noodles (dried noodle and ramyeon) were analyzed by HPLC-ultraviolet detection using immunoaffinity column for clean-up. The limits of detection (LOD) and quantification (LOQ) were 7.5 ${\mu}g$/kg and 18.8 ${\mu}g$/kg, respectively. The calibration curve showed a good linearity, with correlation coefficients $r^2$ of 0.9999 in the concentration range from 20 to 500 ${\mu}g$/kg. Recoveries and Repeatabilities expressed as coefficients of variation (CV) spiked with 200 and 500 ${\mu}g$/kg were $82{\pm}2.7%$ and $87{\pm}1.3%$% in dried noodle, and $97{\pm}1.6%$ and $91{\pm}12.0%$ in ramyeon, respectively. The uncertainty sources in measurement process were identified as sample weight, final volume, and sample concentration in extraction volume as well as components such as standard stock solution, working standard solution, 5 standard solutions, calibration curve, matrix, and instrument. Deoxynivalenol concentration and expanded uncertainty in two matrixes spiked with 200 ${\mu}g$/kg and 500 ${\mu}g$/kg were estimated to be $163.8{\pm}52.1$ and $435.2{\pm}91.6\;{\mu}g$/kg for dried noodle, and $194.3{\pm}33.0$ and $453.2{\pm}91.1\;{\mu}g$/kg for ramyeon using a coverage factor of two which gives a level of statistical confidence with approximately 95%. The most influential component among uncertainty sources was the recovery of matrix, followed by calibration curve.

• Journal of Animal Science and Technology
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• v.52 no.5
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• pp.367-374
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• 2010

Telomeres at the end of chromosomes consist of tandem repeats of (TTAGGG)n DNA sequence and associated proteins. Telomeres have the essential functions in chromosome stability and genome integrity and are hence related to cell senescence and cancer. This study was carried out to quantify the amount of telomeric DNA and establish age prediction equations by using the quantity of telomeric DNA for cattle. Analysis of the telomere quantity of the lymphocytes was performed at different age, across breeds and between different sexes of cattle. We quantified the amount of telomeric DNA by the Q-FISH technique using the telomeric DNA probe in 460 cattle at age of 1~166 months in Korean Cattle and Holstein breeds. In results, we found that the amount of telomeric DNA decreased gradually with age. The amount of telomeric DNA of Korean Cattle was significantly higher than that of Holstein breed (P<0.01). In addition, the amount of telomeric DNA in male was significantly higher than that in female (P<0.01). Using the relationship between age and the amount of telomeric DNA in cattle, age predicting equations were established as a result of regression analysis. Because sex and breeds influenced telomeric DNA quantity, the age prediction equations were estimated separately in Korean Cattle females and Holstein females. The regression equations were $\hat{Y}$=$38.102X^2$-220.103X + 318.309 (P<0.0001, $R^2$=0.8019) in Korean Cattle females and $\hat{Y}$ = $42.799X^2$ - 199.682X + 242.106 (P<0.0001, $R^2$ = 0.8379) in Holstein females, where the X was quantity of telomeric DNA and Y was predicted age in months. These equations predicted the age of cattle with high significance and accuracy and have high R square values. Thus, it could be possible to scientifically predict the age using the above equations for Korean Cattle and Holstein females.

• The Korean Journal of Nuclear Medicine Technology
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• v.15 no.1
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• pp.10-16
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• 2011

Purpose: The partial volume effect occurs because of limit of the spatial resolution. It makes partial loss of intensity and causes SUV to be lower than it should actually be. So the purpose of this study is to calculate recovery coefficient for correcting PVE from phantom study and to compare before and after SUV correction applying to PET/CT examination. Materials and Methods: The flangeless Esser PET phantom consisting of four hot cylinders was used for this study. All of the hot cylinders were filled with FDG solution of 20.72 MBq per 1000 ml, and the phantom background was filled with FDG solution of different concentrations (33.30, 22.20, 16.65 MBq per 6440 ml) to yield H/B ratios of around 4:1, 6:1 and 8:1. Using the Biograph Truepoint 40(SIEMENS, Germany), we applied recovery coefficient method to 30 patients who were diagnosed with lung cancer after PET/CT exam. And then we analyzed and compared SUV before and after correcting partial volume effect. Results: The smaller the diameter of hot cylinder becomes, the more recovery coefficient decreased. When we applied recovery coefficient to clinical patients and compared SUV before and after correcting PVE, before the correction all lesions gave an average max SUV of 7.83. And after the correction, the average max SUV increases to 10.31. The differences in the max SUV between before and after correction were analyzed by paired t test. As a result, there were statistically significant differences (t=7.21, p=0.000). Conclusion: The SUV for quantification should be measured precisely to give consistent information of tumor uptake. But PVE is one of factors that causes SUV to be lower and to be underestimated. We can correct this PVE and calculate corrected SUV using the recovery coefficient from phantom study. And if we apply this correction method to clinical patients, we can finally assess and provide quantitative analysis more accurately.

• Journal of Food Hygiene and Safety
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• v.30 no.2
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• pp.143-149
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• 2015

This study was conducted to simultaneous analysis methods for water soluble vitamins B group (vitamin $B_1$, vitamin $B_2$, nicotinic acid, nicotinamide, vitamin $B_6$) which is used as health functional foods etc. Analytical methods of water-soluble vitamins B group by HPLC were established through instrumental analytical conditions, and the examination of data such as domestic and foreign reliable methods, and papers of journal. HPLC method analyzing water soluble vitamins B group was established using Capcell Pak C18 UG 120 column in 270 nm through test of columns. The validation has been performed on the method to determine linearity, accuracy, limits of quantification (LOQ) and repeatability for water soluble vitamins B group. An excellent linearity ($r^2=0.999$) was observed for vitamin $B_1$, vitamin $B_2$, nicotinic acid, nicotinamide, vitamin $B_6$ in the concentration range ($0.1{\sim}2{\mu}g/mL$). Observed recovery of vitamin $B_1$ was found to be between 100 and 103%, vitamin $B^2$ was found to be between 104 and 112%, nicotinic acid was found to be between 82 and 85%, nicotinamide was found to be between 121 and 124% and vitamin $B_6$ was found to be between 95 and 104%. LOQ of vitamin $B_1$ was found to be $0.04{\mu}g/mL$, vitamin $B_2$ was found to be $0.05{\mu}g/mL$, nicotinic acid was found to be $0.15{\mu}g/mL$, nicotinamide was found to be $0.08{\mu}g/mL$ and vitamin $B_6$ was found to be $0.63{\mu}g/mL$. Repeatability precision for vitamin $B_1$ was found to be 0.4%, vitamin $B_2$ was found to be 0.4%, nicotinic acid was found to be 0.5%, nicotinamide was found to be 0.7% and vitamin $B_6$ was found to be 0.4% relative standard deviation (RSD). Also, verify the accuracy of the simultaneous analysis methods, we monitored the labeled contents of the health functional foods and children's preferred foods.

• Journal of Food Hygiene and Safety
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• v.32 no.5
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• pp.381-388
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• 2017

In this study, we investigated the levels of natural preservatives of benzoic acid, sorbic acid, and propionic acid in spices. The quantitative analysis was performed using high performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) for benzoic acid and sorbic acid and gas chromatography-mass spectrometry (GC-MS) for propionic acid. The sample was extracted with ethanol using sonication, then centrifuged and evaporated to dryness and redissolved to 1 mL with ethanol to use for the instrumental analysis. The analytical method was validated based on linearity, recovery, limit of detection (LOD), and limit of quantification (LOQ). This method was suitable to determine low amounts of naturally occurring preservatives (benzoic acid, sorbic acid, and propionic acid) in various spices. Benzoic acid, sorbic acid, and propionic acid were found in 165 samples, 88 samples, and 398 samples, respectively from the total of 493 samples. The concentration of benzoic acid, sorbic acid, and propionic acid were ranged at ND-391.99 mg/L, ND-57.70 mg/L, and ND-188.21 mg/L in spices, respectively. The highest mean levels of benzoic acid, sorbic acid, and propionic acid were found in cinnamon (167.15 mg/L), basil leaves (22.79 mg/L), and white pepper (51.48 mg/L), respectively. The results in this study provide ranges of concentration regarding naturally occurring benzoic acid, sorbic acid, and propionic acid in spices. Moreover, the results may use to the case of consumer complaint or trade friction due to the inspection services of standard criteria for the preservatives of spices.

• Journal of Food Hygiene and Safety
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• v.32 no.5
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• pp.424-433
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• 2017

Antioxidants are used in the manufacturing of commercial food packages made of polyolefin plastic such as polyethylene and polypropylene for the purpose to delay the oxidation reaction of the polymer due to oxygen or traces of ozone in the atmosphere. Additives in plastics may be migrated from the packaging materials into foods, thereby presenting a potential health risk to the consumer. Therefore, it is necessary to determine migration level of antioxidants from food packaging materials to foodstuffs in order to take proactive management. In this study, we have developed a method for the analysis of 10 antioxidants, which are butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), Cyanox 2246, 425 and 1790, Irgafos 168, and Irganox 1010, 1330, 3114 and 1076, migrated from the food packaging materials into four food simulants for aqueous, acidic, alcoholic and fatty foods. The antioxidants were determined by reversed-phase high-performance liquid chromatograph-ultraviolet detector with 276 nm after solid-phase extraction with a hydrophilic-lipophilic balance (HLB) cartridge or dilution with isopropanol. The analytical method showed a good linearity of coefficient ($R^2{\geq}0.99$), limits of detection (0.11~0.41 mg/L), and limits of quantification (0.34~1.24 mg/L). The recoveries of antioxidants spiked to four food simulants ranged from 71.3% to 109.4%. The migrated antioxidants in this study were within the safety levels that resulted from the safety assessment by the estimated daily intake to the tolerable daily intake.

• Journal of Food Hygiene and Safety
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• v.32 no.4
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• pp.329-335
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• 2017

Analysis method was presented for the simultaneous determination of nine bisphenol A related compounds such as bisphenol A (BPA), phenol, p-tert-butylphenol, bisphenol A diglycidyl ether (BADGE), $BADGE{\cdot}2H_2O$, $BADGE{\cdot}2HCl$, bisphenol F diglycidyl ether (BFDGE), $BFDGE{\cdot}2H_2O$ and $BFDGE{\cdot}2HCl$ migrated from inner coatings of metal food cans by high performance liquid chromatography (HPLC) with fluorescence detection. The method was validated by examining the linearity of calibration curve, the limit of detection (LOD), the limit of quantification (LOQ), recovery and uncertainty. The migration tests of nine BPA related compounds were carried out with four food simulants; deionized water (DW), 4% acetic acid, 50% ethanol and n-heptane. There was not any compound detected in DW, 4% acetic acid and 50% ethanol at $60^{\circ}C$ for 30 min and n-heptane at $25^{\circ}C$ for 60 min. BPA and phenol were migrated into 4% acetic acid and 50% ethanol at $95^{\circ}C$ for 30 min. The concentrations were ranged from 0 to $10.77{\mu}g/L$ of BPA and from 0 to $2.35{\mu}g/L$ of phenol. Canned foodstuffs mostly have long-term shelf life. We investigated migration of nine BPA related compounds according to the variation in storage periods (0~90 days) and temperatures (4, 25 and $60^{\circ}C$). All compounds were not founded during 90 days at $4^{\circ}C$ and $25^{\circ}C$, respectively. However BPA and $BADGE{\cdot}2H_2O$ were founded in DW and 4% acetic acid at $60^{\circ}C$. The migration levels of BPA and $BADGE{\cdot}2H_2O$ were close to the value of LOQ, respectively and did not change significantly as storage period. It was founded from results that the migration of BPA related compounds from metal food cans was controlled to a safe level.