• Journal of Food Hygiene and Safety
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• v.30 no.3
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• pp.272-280
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• 2015

A simultaneous official method was developed for the determination of phorate and its metabolites (phorate sulfoxide, phorate sulfone, phorate oxon, phorate oxon sulfoxide, phorate oxon sulfone) in livestock samples. The analytes were quantified and confirmed via liquid chromatograph-tandem mass spectrometer (LC-MS/MS) in positive ion mode using multiple reaction monitoring (MRM). Phorate and its metabolites were extracted from beef and milk samples with acidified acetonitrile (containing 1% acetic acid) and partitioned with anhydrous magnesium sulfate. Then, the extract was purified through primary secondary amine (PSA) and C18 dispersive sorbent. Matrix matched calibration curves were linear over the calibration ranges (0.005-0.5 mg/L) for all the analytes into blank extract with $r^2$ > 0.996. For validation purposes, recovery studies were carried out at three different concentration levels (beef 0.004, 0.04 and 0.2 mg/kg; milk 0.008, 0.04 and 0.2 mg/kg, n = 5). The recoveries were within 79.2-113.9% with relative standard deviations (RSDs) less than 19.2% for all analytes. All values were consistent with the criteria ranges requested in the Codex guidelines. The limit of quantification was quite lower than the maximum residue limit (MRL) set by the Ministry of Food and Drug Safety (0.05 mg/kg). The proposed analytical method was accurate, effective and sensitive for phorate and its metabolites determination and it will be used to as an official analytical method in Korea.

• Journal of the Korean Society for Nondestructive Testing
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• v.34 no.4
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• pp.311-317
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• 2014

The Pressurized water reactor owners group (PWROG) developed and applied a risk-informed in-service inspection (RI-ISI) program, as an alternative to the existing ASME Section XI' sampling inspection method. The RI-ISI programs enhance overall safety by focusing inspections of piping at high safety significance (HSS) locations where failure mechanisms are likely to be present. Additionally, the RI-ISI program can reduce nondestructive evaluation (NDE) exams, man-rem exposure for inspectors, and inspection time, among other benefits. The RI-ISI method of in-service piping inspection was applied to 3 units (KSNPs: Korea standard nuclear power plants) and is being deployed to the other units. In this paper, the results of RI-ISI for a Framatome type (France CPI) nuclear power plant are presented. It was concluded that application of RI-ISI to the plant could enhance and maintain plant safety, as well as provide the benefits of greater reliability.

• ALGAE
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• v.38 no.2
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• pp.127-139
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• 2023

Cryptic stages of diverse macroalgae present in natural substrata, "the bank of microscopic forms", were isolated into clonal cultures and identified based on both morphological characteristics and DNA barcoding. Approximately 120 clonal isolates from 308 natural substratum samples were collected from the entire coastline of Kuwait. Amongst these isolates, 77 (64%) were identified through DNA barcoding using the nuclear ribosomal small subunit, RuBisCO spacer (ITS2, tufa, rbcL, psaA, and psbA) and sequencing. Twenty-six isolates (34%) were identified in the division Chlorophyta, 18 (23%) as Phaeophyceae, and 33 (43%) as Rhodophyta. For all DNA sequences in this study, species-level cut off applied was ≥98% homology which depend entirely on the markers used. Three putative new records of Chlorophyta new for the Arabian Gulf were made: Cladophora laetevirens (Dillwyn) Kützing, Ulva torta (Mertens) Trevisan and Ulvella leptochaete (Huber) R. Nielsen, C. J. O'Kelly & B. Wysor in Nielsen, while Cladophora gracilis Kützing and Ulva ohnoi M. Hiraoka & S. Shimada are new records for Kuwait. For Phaeophyceae, Ectocarpus subulatus Kützing and Elachista stellaris Areschoug were new records for the Gulf and Kuwait. In the Rhodophyta, Acrochaetium secundatum (Lyngbye) Nägeli in Nägeli & Cramer, Ceramium affine Setchell & N. L. Gardner, Gelidium pusillum var. pakistanicum Afaq-Husain & Shameel and Dasya caraibica Børgesen are new records for the Gulf and Kuwait, while the red alga Stylonema alsidii (Zanardini) K. Drew is a new record for Kuwait. Several isolates identified corresponded to genera not previously reported in Kuwait and / or the Arabian Gulf, such as Porphyrostromium Trevisan, a new genus from the Bangiales, and two unidentified species for the Planophilaceae Škaloud & Leliaert. The isolates cultivated from substrata enhance understanding of the marine macroalgal diversity in the region and confirmed that the Germling Emergence Method is suitable for determining the actual diversity of a given study area through isolation from cryptic life-history phases.

• Analytical Science and Technology
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• v.25 no.2
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• pp.146-151
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• 2012

An analytical method was developed for the measurement of uranium isotope in ground water using the liquid scintillation counting technique. A LKB Wallac Quantulus 1220 liquid scintillation counter (LSC) equipped with pulse shape analyzer (PSA) and a solvent extraction method were used for the measurement of uranium isotope in ground water samples. The effect of solution volume on the extraction efficiency was evaluated for 100 to 1000 mL solutions using a NIST standard reference material (NIST SRM 4321C). The effect of groundwater pH on the extraction efficiency was also investigated for pH ranging from 0.5 to 10. It was found that the extraction efficiency had a strong dependence on pH showing a maximum at pH 2. In contrast, the effect of groundwater volume on the extraction efficiency was negligible in the range investigated. According to the method, the extraction efficiency of uranium isotopes was near 96% and the lower detection limit for uranium was 0.018 Bq/L with the counting time of 300 min. The result of this study was also verified by the conventional ICP-MS measurement. It is demonstrated that the suggested method is valuable to the determination of the optimum extraction and measurement conditions for uranium in ground water. The method was successfully applied to the ground water at four locations near the Daejeon province. It was found that the uranium content and the isotopic ratio of $^{234}U/^{238}U$ at the locations ranged 0.59~6.69 Bq/L and 0.72~1.40, respectively.

• Journal of Food Hygiene and Safety
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• v.33 no.2
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• pp.110-117
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• 2018

The aim of this study was to develop an analytical method for the quantification of diazepam residues in fishery products, using liquid and gas chromatography-tandem mass spectrometry (LC-MS/MS and GC-MS/MS). The sample utilized in the study was extracted from the fish sample (crucian carp) using 0.1% formic acid in acetonitrile. For the utilization of the purification process, the dispersive solid phase extraction (dSPE) was used for LC-MS/MS, dSPE and SPE was used for GC-MS/MS, respectively. To be sure, the standard calibration curves showed a good linearity as the noted correlation coefficients, $r^2$ was > 0.99. The average recoveries for accuracy ranged in 99.8~124% for the samples which were fortified at three different levels (0.001, 0.002 and 0.010 mg/kg). The correlation coefficient for the precision effect was measured at a range of 4.01~11.8%. The limit of detection (LOD) for the diazepam analysis was 0.0004 mg/kg, and the limit of the quantification (LOQ) was 0.001 mg/kg. The proposed analytical method was characterized with a high accuracy and acceptable sensitivity to meet the established Codex Alimentarius Commission (CAC/GL71-2009) guideline requirements. We therefore established the optimal analysis method for the determination of diazepam in the fishery products using LC-MS/MS and GC-MS/MS. It would be applicable to analyze the diazepam residues in fishery products in further studies on this subject.

• Korean Journal of Environmental Agriculture
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• v.42 no.3
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• pp.203-210
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• 2023

Ferimzone Z is a fungicide for effectively controlling rice blast. Under light irradiation conditions, it undergoes a rapid conversion to its E-stereoisomer. Given the importance of isomers in risk assessments of residues in crops, an analytical method was developed for individual isomer quantification. A comparative analysis performed using two columns in HPLC-MS/MS demonstrated that the isomers were successfully separated using the Cadenza column. For the brown rice sample preparation, 5 g of the homogenized sample was saturated with 7 mL of water. The sample was then extracted with a 10 mL mixed solvent of acetonitrile and ethyl acetate (1:1, v/v) that contained 0.1% formic acid, and it was subsequently partitioned with magnesium sulfate and sodium chloride. The upper layer was purified using dSPE containing C₁₈ and PSA sorbents. The established method was subjected to method validation, and it showed recovery rates of 90.6-98.8% (RSD ≤ 3.9%) at concentrations of 0.01, 0.1, 2 mg/kg, with a soft matrix effect (%ME) ranging from -3.1% to +6.5%. This method can be employed in monitoring studies of brown rice to determine the conversion ratio from the Z isomers to the E isomers.

• Journal of Adhesion and Interface
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• v.10 no.3
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• pp.148-153
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• 2009

An atmospheric plasma pre-treatment method was applied to PU foam, Leather (Action), Rubber to improve its adhesion using solvent and water soluble type pressure sensitive adhesion in atmospheric plate type reactor. In order to investigate the optimum reaction condition of plasma treatment, type of reaction gas (nitrogen), rate of gas flow (30~100 mL/min), and reaction time (0~30 s) were examined in a plate plasma reactor. The result of the surface modification with respect to the treatment procedure was characterized by using SEM. Due to a de-crease of the contact angle of various materials, the greatest adhesion strength was achieved at optimum condition such as flow rate of 100 mL/min, reaction time of 10 second for an atmospheric plasma treatment of the PU foam, EVA foam, Leather (Action) and Rubber also resulted in the improvement of the adhesion.

• The Korean Journal of Urological Oncology
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• v.16 no.3
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• pp.126-134
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• 2018

Purpose: The purpose of this study is to compare the radiation therapy (RT) and radical prostatectomy (RP) of high-risk or locally advanced prostate cancer (PC) patients after neoadjuvant hormonal therapy (NHT). Materials and Methods: This retrospective study evaluated patients underwent RT (42 patients) or RP (152 patients) after NHT at a single center during 2003-2014. Times to biochemical recurrence (BCR), pelvic local recurrence (PLR), metastasis, clinical painful symptom progression (CPSP), castration-resistant PC (CRPC), and overall survival were compared between the RT and RP groups, after adjustment for TN stage, using the Kaplan-Meier method and log-rank test. Results: Significant inter-group differences were observed for age, Gleason score, initial PSA, and clinical and pathological T stages (all p<0.05). During a median follow-up of 71.7 months, the overall incidences of BCR, PLR, metastasis, CPSP, CRPC, and death were 49.5%, 16.5%, 8.3%, 7.7%, 7.7%, and 17.5%, respectively. The median times to BCR were 100 months for RT and 36.2 months for RP (p=0.004), although the median times were not reached for the other outcomes (all p>0.05). The independent predictor of CPSP was RP (hazard ratio, 0.291; p=0.013). Conclusions: Despite significantly different baseline parameters, RP provided better CPSP-free survival than RT among patients with localized high-risk or locally advanced PC.

• Journal of Animal Reproduction and Biotechnology
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• v.39 no.2
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• pp.88-94
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• 2024

Background: Using cryovial for freezing dog spermatozoa provides a practical method to increase extended sperm volume and shorten the time required for equilibration by using a simple freezing techniques. The purpose of this study was to determine the optimal thawing condition for dog sperm cryopreservation using cryovials. Methods: For sperm freezing, cryovials with 200 × 10⁶ sperm/mL were cooled after the addition of tris egg yolk extender (TEY) at 4℃ for 20 min, then TEY with 4% glycerol was added and equilibrated for another 20 min before being aligned over LN₂ vapor for another 20 min and plunged directly into LN₂. Spermatozoa were thawed in a water bath at 37℃ for varying times (25 sec, 60 sec, 90 sec, and 120 sec) in the first experiment. In the second experiment, spermatozoa were thawed in a water bath at various temperatures and times (37℃ for 1 min, 37℃ for 1 min with gentle stirring, 24℃ for 24 min, and 75℃ for 20 sec). In these experiments, the effect of thawing conditions on motility parameters, viability (SYBR-14/PI), and acrosome integrity (PSA/FITC) of spermatozoa were investigated. Results: The post-thaw sperm motility parameters, viability, and acrosome integrity were not significantly different across the experimental groups. Conclusions: In this study, the characteristics of spermatozoa frozen using cryovials were not significantly affected by various thawing conditions.

• Journal of Food Hygiene and Safety
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• v.34 no.2
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• pp.124-134
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• 2019

An analytical method was developed for the determination of broflanilide and its metabolites in agricultural products. Sample preparation was conducted using the QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) method and LC-MS/MS (liquid chromatograph-tandem mass spectrometer). The analytes were extracted with acetonitrile and cleaned up using d-SPE (dispersive solid phase extraction) sorbents such as anhydrous magnesium sulfate, primary secondary amine (PSA) and octadecyl ($C_{18}$). The limit of detection (LOD) and quantification (LOQ) were 0.004 and 0.01 mg/kg, respectively. The recovery results for broflanilide, DM-8007 and S(PFP-OH)-8007 ranged between 90.7 to 113.7%, 88.2 to 109.7% and 79.8 to 97.8% at different concentration levels (LOQ, 10LOQ, 50LOQ) with relative standard deviation (RSD) less than 8.8%. The inter-laboratory study recovery results for broflanilide and DM-8007 and S (PFP-OH)-8007 ranged between 86.3 to 109.1%, 87.8 to 109.7% and 78.8 to 102.1%, and RSD values were also below 21%. All values were consistent with the criteria ranges requested in the Codex guidelines (CAC/GL 40-1993, 2003) and the Food and Drug Safety Evaluation guidelines (2016). Therefore, the proposed analytical method was accurate, effective and sensitive for broflanilide determination in agricultural commodities.