• Analytical Science and Technology
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• v.25 no.6
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• pp.435-440
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• 2012

A liquid chromatography-electrospray ionization-tandem mass spectrometry method (LC-ESI-MS/MS) was used for determining perchlorate in the Gum-River surface water. Sample was directly injected into LC-ESI-MS/MS after the filtrations using PTFE filter paper. The coefficient of variation of perchlorate was less than 3% and the limit of quantification was 0.17 ${\mu}g/L$. Water samples were collected from thirty-five basins of Gum-River on February, April and June 2012, respectively. As a result, perchlorate was detected in the concentration range of 0.23-3.73 ${\mu}g/L$ (mean 0.20 ${\mu}g/L$) in the frequency of 15% in general surface water and in the concentration range of 0.36-25.10 ${\mu}g/L$ (mean 1.69 ${\mu}g/L$) in the frequency of 36% in surface water samples near industry area.

• KOGO NEWS
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• v.5 no.4
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• pp.4-5
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• 2005

• Analytical Science and Technology
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• v.16 no.2
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• pp.125-133
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• 2003

In order to determine the contents of trans-resveratrol in red wine, which was mainly consumed in Korea, both LC/MS-ESI and LC/MS-APCI methods were used after solid-phase (Sep-Pak $C_{18}$-cartridges) extraction. The contents of trans-resveratrol obtained by LC/MS-ESI were detected in the range of $0.06-4.31{\mu}g/mL$. The recoveries were ranged from 88.4 to 97.9%. The values of relative standard deviation were ranged from 0.6 to 4.6% and the detection limit was $0.001{\mu}g/mL$. The contents of trans-resveratrol obtained by LC/MS-APCI were detected in the range of $0.09-4.02{\mu}g/mL$ and the detection limit was $0.005{\mu}g/mL$.

• Korean Journal of Pharmacognosy
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• v.50 no.1
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• pp.65-71
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• 2019

One of the oriental medicine prescriptions, Sagunja-tang consists of four herbal medicines (Ginseng Radix, Poria Sclerotium, Atractylodis Rhizoma Alba, and Glycyrrhiziae Radix et Rhizoma) and has been used as a medicine to enhance tonify the function of spleen and stomach in Korea. In this study, we conducted simultaneous analysis of the 9 marker components, liquiritin apioside, liquiritin, ginsenoside Rg1, liquiritigenin, ginsenoside Rb1, glycyrrhizin, atractylenolide III, atractylenolide II, and atractylenolide I in Sagunja-tang using a liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS/MS). Marker compounds were separated on a Waters Acquity UPLC BEH $C_{18}$ analytical column ($2.1{\times}100mm$, 1.7 mm) and the column was maintained at $45^{\circ}C$. The mobile phase consists of 0.1% (v/v) aqueous formic acid and acetonitrile with gradient condition. The LC-MS analysis was performed using a Waters ACQUITY TQD LC-MS/MS system with multiple reaction monitoring (MRM) method in the positive and negative modes. The calibration curves of the nine marker components showed good linearity with coefficient of determination ${\geq}0.9984$ within tested range. The limits of detection and limits of quantification values were 0.27-2.42 ng/mL and 0.81-7.27 ng/mL, respectively. The concentrations of tested 9 analytes in the lyophilized Sagunja-tang sample using the established LC-ESI-MS/MS MRM method were detected up to 16.593 mg/g. These results can be useful as a basic data for the quality control of an oriental medicine prescriptions.

• Journal of Food Hygiene and Safety
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• v.37 no.2
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• pp.46-54
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• 2022

Known for its effectiveness in weight loss and diabetes prevention, Gymnema sylvestre products can be found in the US, Japanese, and Indian markets. However, the recommended dosage or safety of these products has not yet been proven. Therefore, development of an analytical method for detecting the content of Gymnema sylvestre in food products is required. Accordingly, this study proposes an analysis method that can examine Gymnema sylvestre in food using LC-ESI-MS/MS and KASP (Kompetitive Allele-Specific PCR) markers. In LC-ESI-MS/MS, a simultaneous analysis method for gymnemic acid and deacylgymnemic acid was optimized using negative ionization mode, and its validation test was completed for solid and liquid samples. In addition, KASP markers were prepared by finding the specific SNP of G. sylvestre in ITS2 and matK through DNA barcodes. The two KASP markers returned positive FAM fluorescence result when combined with G. sylvestre, and this aspect was confirmed in raw G. sylvestre as well. The applicability of the method was tested on 21 different food and healthy functional products containing G. sylvestre purchased on the internet. As a result, although there was a difference in the ratios of gymnemic acid and deacylgymnemic acid in LC-ESI-MS/MS, the index component was detected in all 21 products samples. In the KASP analysis, 9 products returned positive FAM result, and the rest of the products were found to be containing G. sylvestre extract. This study is the first study to use the dual system of LC-ESI-MS/MS and KASP for the analysis of G. sylvestre. The study has confirmed that these two methods are applicable to the examine G. sylvestre content in food products.

• Analytical Science and Technology
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• v.21 no.6
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• pp.535-542
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• 2008

A liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI/MS/MS) method was developed for the determination and confirmation of clenbuterol in bovine muscle and milk. Clenbuterol and clenbuterol-D9 using as an internal standard in samples were extracted with ethyl acetate after hydrolysis and evaporated to dryness. The extracts were dissolved in 20% methanol and cleaned using HLB solid-phase extraction cartridge. The analytes were detected by LC-ESI/MS/MS on a $C_{18}$ column. Mass spectral acquisition was done in selected reaction monitoring (SRM) in positive ion mode to provide a high degree of sensitivity. Using MS/MS with SRM mode, the transitions (precursor to product) monitored were m/z 277${\rightarrow}$203 for clenbuterol, and m/z 286${\rightarrow}$204 for internal standard. The limits of quantitation (LOQ) and mean recoveries of clenbuterol in bovine muscle were $0.2{\mu}g/kg$ and 84.3~91.1%, respectively. The LOQ and mean recoveries in milk were $0.05{\mu}g/kg$ and 87.7~98.3%, respectively.

• Journal of Korean Society on Water Environment
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• v.29 no.3
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• pp.409-419
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• 2013

In this study, the analytical method for 27 residual pharmaceuticals in raw water was developed. Online sample preconcentration/extraction and analysis with high resolution Orbitrap mass spectrometry (LC-ESI/Orbitrap MS) were performed. The calibration curves showed good linearities (above $r^2$ = 0.998) in the range of 5 ~ 1,000 ng/L. The method detection limit and the limit of quantification were 1.1 ~ 10.0 ng/L and 3.4 ~ 31.7 ng/L, respectively. Recoveries of the target compounds were between 70.1% and 115.8% (except cefadroxil, cefradine, vancomycin, and iopromide (50.2 ~ 67.0%)). The optimized analytical method can be useful to determine the residual pharmaceuticals in raw water.

• Analytical Science and Technology
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• v.17 no.2
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• pp.117-129
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• 2004

Amitrole in environment, difficult to be analyzed by GC or GC/MS due to high polarity and low volatility, was analyzed by LC/ESI/MS in the study. Maximum peak intensity of amitrole in LC/MS/ESI mass spectrum is m/z 85 of protonated molecular ion $(M+H)^+$ with 30V of cone voltage at SIR mode. It was confirmed that ratios between main ion of amitrole, 85 of protonated molecular ion, and m/z 58 fragmented ion of amitrole, had increased corresponding with the increment of cone voltage from 20V to 70V. The isotope molecular weight of amitrole was $86([M+H])^+$ at LC/MS analysis and the mass spectrum ratio between 85 mass and 86 mass was not different by the change of concentration but similar to theoretical ratio(less than 10% standard deviation).The linearity of standard calibration curve under same condition with sample treatment method had $y=1.09354e^6X+26947.2$ and $r^2=0.99$. Recovery rates in water and soil samples were 77.64~83.44% and 71.11~79.44%, respectively. Reliability of the analysis was performed with 5 repeated measurements at each level of standard concentration and the result showed that relative standard deviation was less than 10%; therefore, the extraction and analysis method in the study suggested that it would be reliable to measure amitrole in water and soil media.

• Journal of the Korean Chemical Society
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• v.55 no.4
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• pp.626-632
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• 2011

Phoxim, which is one of veterinary drugs, is a well-known antiparasitic agent in wide use. In this paper, phoxim was extracted from cattle and pig tissue using solid-phase extraction (SPE) employing a silica cartridge with acetonitrile. Liquid chromatography/electrospray ionization-tandem mass spectrometry (LC/ESI-MS/MS) for the analysis of phoxim from animal tissue was presented. Phoxim was detected on a $C_{18}$ column ($2.1{\times}100\;mm$, $3.5\;{\mu}m$) using a mobile phase of 0.1% formic acid in water and acetonitrile. A linear correlation observed in the calibration curves for cattle (0.0048~2.0 mg/kg) and pig (0.0055~2.0 mg/kg) showed above $r^2$=0.995. Accuracy measured at concentrations ranging from 0.0048 to 0.2 mg/kg was the range of 68.2~106.9%. Limit of detection (LOD) and limit of quantitation (LOQ) were the range of 0.0014~0.0017 mg/kg and 0.0048~0.0055 mg/kg, respectively. The precision (RSD%) was below 11.2%.

• Analytical Science and Technology
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• v.28 no.4
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• pp.299-307
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• 2015

In May 2012, a safety hazard issue arose because some kiwifruit growers in New Zealand had sprayed streptomycin to prevent kiwifruit canker. Therefore, for food safety management, analytical methods to determine streptomycin residues in kiwifruits are required. We developed an analytical method to determine streptomycin residues in kiwifruit samples using liquid chromatograph tandem mass spectrometer (LC-ESI-MS/MS). Streptomycin residues in samples were extracted using 1% formic acid in methanol, centrifugation for 10 min, and subsequent supernatant filtration. Purified samples were subjected to LC-ESI-MS/MS to confirm presence of and quantify streptomycin residues. Average streptomycin recoveries (6 replicates each sample) were in the range of 94.8%-110.6% with relative standard deviations of <10%. The linearity of the concentration range of 0.01-5.0 mg/kg using a matrix-matched calibration gave R² = 0.9995. The limit of quantification (LOQ) was 0.01 mg/kg. Results showed that our analytical method is rapid, simple, and sensitive, with easy sample preparation.