• Natural Product Sciences
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• v.18 no.3
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• pp.158-165
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• 2012

A UPLC method for the simultaneous determination of seven compounds was established for the quality control in H. cordata. The UPLC was performed on a $C_{18}$ HSS T3 $2.1{\times}100$ mm, 1.8 ${\mu}m$ column during a 13 minute gradient elution of 0.2% aqueous acetic acid and acetonitrile with the flow rate of 0.2 mL/min at $30^{\circ}C$. The UPLC method was validated according to the ICH guideline of analytical procedures with respect to precision, accuracy, and linearity. The limit of determination and quantitation for the seven compounds were 0.01-0.09 and 0.03-0.28 ${\mu}g/mL$, respectively. The calibration curves of all seven compounds showed good linearity ($r^2$ > 0.999). The intra-day and inter-day the RSD values used to evaluate the precision of analysis were less than 0.9%. The recoveries of quantified compounds ranged from 98.63 to 103.85%. The developed UPLC method was found to be effective, convenient and sensitivity for quantitative analysis of seven compounds in H. cordata. This work could be provided a baseline source for quality control of H. cordata.

• Korean Journal of Environmental Agriculture
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• v.40 no.2
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• pp.142-147
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• 2021

BACKGROUND: Agricultural use and pest control purposes of pesticides may lead to livestock products contamination. Thiodicarb and its degraded product, methomyl, are carbamate insecticides that protect soya bean, maize, fruit, and vegetables and control flies in animal and poultry farms. For maximum residue limit enforcement and monitoring, the JMPR residue definition of thiodicarb in animal products is the sum of thiodicarb and methomyl, expressed as methomyl. This residue definition was set to consider the fact that thiodicarb was readily degraded to methomyl in animal commodities. And therefore the simultaneous analytical method of thiodicarb and methomyl is required for monitoring in livestock products. METHODS AND RESULTS: The study was conducted using a quick, easy, cheap, effective, rugged, and safe (QuEChERS) method and HPLC-MS/MS to determine the thiodicarb and methomyl in livestock products. The limit of quantitation (LOQ) was 0.01 mg/kg for livestock products, including beef, pork, chicken, milk, and egg. The coefficient of determinations (r²) for the calibration curve were > 0.99, which was acceptable values for linearity. Average recoveries at spiked levels (LOQ, 10LOQ, and 50LOQ, n=5) in triplicate ranged from 73.2% to 102.1% and relative standard deviations (RSDs) were less than 10% in all matrices. CONCLUSION: The analytical method was validated for the performance parameters (specificity, linearity, accuracy, and precision) in livestock products to be acceptable by the CODEX guidelines.

• Korean Journal of Environmental Agriculture
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• v.42 no.3
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• pp.220-230
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• 2023

Imidacloprid is a neonicotinoid insecticide widely used for insect control in a variety of crops. The evaluation of imidacloprid total residues in animal feeds derived from crop by-products is required to ensure the safety of livestock products. We performed simultaneous LC/MS/MS analyses of imidacloprid and its metabolites in five different livestock products including beef, pork, chicken, milk and egg from domestic markets. The methods for sample preparation and instrumental analysis were established by modifying QuEChERS method to meet the Codex guidelines. The methods generated 0.0035 mg/kg of the limit of determination (LOD), 0.01 mg/kg of the limit of quantitation (LOQ) and standard calibration linearity with >0.983 of the coefficients of determination (R²). The methods exhibited the recovery values of imidacloprid and its metabolites ranging from 65.66 to 119.27% without any interference between matrices. Imidacloprid total residues in the livestock products were found as values lower than the LOQ and maximum residue limits (MRLs). This study suggests that the methods are successfully applicable for the safety evaluation of imidacloprid total residues in livestock products from domestic markets.

• Analytical Science and Technology
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• v.33 no.6
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• pp.233-239
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• 2020

This study was performed to develop an analytical method using Carrez reagents as the precipitant to effectively and easily remove proteins and lipids while pretreating samples for the simultaneous determination of preservatives, including dehydroacetic acid (DHA), sorbic acid (SA), benzoic acid (BA), methyl ρ-hydroxybenzoate (MP), ethyl ρ-hydroxybenzoate (EP), propyl ρ-hydroxybenzoate (PP), isopropyl ρ-hydroxybenzoate (IPP), butyl ρ-hydroxybenzoate (BP), and isobutyl ρ-hydroxybenzoate (IBP). The effective selectivity was determined by HPLC separation analysis for nine preservatives in the test solution, after removing interfering materials such as lipids and proteins. The method developed in this study showed excellent linearity at 0.999 or higher. The limit of detection (LOD) ranged from 0.09 to ~0.12 mg/L and the limit of quantitation (LOQ) was ~0.280.37 mg/L. The results of the recovery test on processed foods, including pickles, cheeses, processed meat products, beverages, sauces, and emulsified foods showed DHA, SA, BA, MP, EP, IPP, PP, IBP, and BP at 90.9~107.7 %, 85.4~113.7 %, 90.7~111.6 %, 84.5~111.2 %, 81.3~110.9 %, 82.5~102.2 %, 81.1~110.0 %, 80.9~109.0 %, and 82.4~110.3 %, respectively. The probability of the simultaneous analytical method developed in this study as a quantitative method was confirmed for various processed foods.

• Bulletin of the Korean Chemical Society
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• v.31 no.5
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• pp.1192-1198
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• 2010

Pharmaceuticals and personal care products (PPCPs) are emerging contaminants in the aquatic environment. Many pharmaceuticals are not completely removed during wastewater treatment, leading to their presence in wastewater treatment effluents, rivers, lakes, and ground water. Here, we developed analytical methods for monitoring ten pharmaceuticals from surface water by LC/ESI-MS/MS. For sample clean-up and extraction, MCX (mixed cation exchange) and HLB (hydrophilic-lipophilic balance) solid-phase extraction (SPE) cartridges were used. The limits of detection (LOD) in distilled water and the blank surface water were in the range of 0.006 - 0.65 and 1.66 - 45.05 pg/mL, respectively. The limits of quantitation (LOQ) for the distilled water and the blank surface water were in the range of 0.02 - 2.17 and 5.52 - 150.15 pg/mL, respectively. The absolute recoveries for fortified water samples were between 62.1% and 125.4%. Intra-day precision and accuracy for the blank surface water were 2.9% - 24.1% (R.S.D.) and -16.3% - 16.3% (bias), respectively. In surface wastewater near rivers, chlortetracycline and acetylsalicylic acid were detected frequently in the range of 0.017 - 5.404 and 0.029 - 0.269 ng/mL, respectively. Surface water near rivers had higher levels than surface water of domestic treatment plants.

• Analytical Science and Technology
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• v.32 no.6
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• pp.217-224
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• 2019

In this study, to evaluate the effectiveness and safety of oral therapy using Gastrodiae Rhizoma, a new HPLC-PDA analysis method was developed for the simultaneous quantitation of the three major components: (1) gastrodin, (2) gastrodigenin, and (3) p-hydroxybenzaldehyde, in steam processed and unprocessed tubers of Gastrodia elata Blume. The clear separation of the three components was achieved on a C18 column (250 × 4.6 mm, 5 ㎛) by gradient elution using water (including 0.1 % formic acid) and acetonitrile as the mobile phase. The flow rate was 1.0 mL/min, and the UV detector wavelength was set at 270 nm. The results demonstrate satisfactory linearity, recovery, precision, accuracy, stability, and robustness. The established HPLC-PDA method was applied to quantify three major compounds in 59 samples of G. elata Blume tubers. Finally, the steam processed and unprocessed tubers of G. elata Blume were successfully distinguished by pattern recognition analysis.

• Environmental Engineering Research
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• v.13 no.4
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• pp.216-223
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• 2008

An efficient method for the simultaneous determination of eleven phenolic endocrine-disrupting chemicals (EDCs) present in wastewater influent samples was described. The 11 phenolic EDCs including alkylphenols, chlorophenols, and bisphenol A were determined by gas chromatography/mass spectrometry-selected ion monitoring (GC/MS-SIM) following two work-up methods for comparison; isobutoxycarbonyl (isoBOC) derivatization and tert-butyldimethylsilyl (TBDMS) derivatization. The wastewater influent samples containing the 11 EDCs were adjusted to pH 2 with $H_2SO_4$ and then cleaned up with n-hexane. Next, they were subjected to solid-phase extraction (SPE) with XAD-4 resin and subsequently converted to isoBOC or TBDMS derivatives for sensitivity analysis with gas chromatography/mass spectrometry-selected ion monitoring (GC/MSSIM). Following isoBOC derivatization and TBDMS derivatization, the recoveries were 86.6-105.2% and 97.6-142.7%, the limits of quantitation (LOQ) for the 11 phenolic EDCs for SIM was 0.001-0.050 ng/mL and 0.003-0.050 ng/mL, and the SIM responses were linear with the correlation coefficient varying by 0.9717-0.9995 and 0.9842-0.9980, respectively. When these methods were applied to five selected wastewater influent samples, for isoBOC derivatization and TBDMS derivatization the ranges of concentration detected were 0.2-99.6 ng/mL and 0.4-147.4 ng/mL, respectively.

• Korean Journal of Pharmacognosy
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• v.49 no.1
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• pp.70-75
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• 2018

Acer tegmentosum Maxim (ATM) has been used to treat hepatic disorders in traditional oriental medicine. However, there is little information about phytochemical constituents for quality control of ATM. In this study, we developed and established a simultaneous analytical method of the 10 marker compounds (three coumarins, 3 flavonoids, 1 lignan, 3 phenolics) in ATM using ultra-performance liquid chromatography-mass spectrometry (UPLC-MS/MS). Chromatographic separation of ten target analytes was achieved with a Waters Acquity UPLC BEH $C_{18}$ analytical column ($2.1{\times}100mm$, $1.7{\mu}m$), using a mobile phase of 0.1% (v/v) formic acid in water and acetonitrile with gradient elution. Identifications and quantitation of all analytes were performed using a Q-Exactive UPLC-MS/MS system. Correlation coefficients of the calibration curve for all analytes were ${\geq}0.9986$. The values of limits of detection and quantification of all analytes were 0.5-10.0 and 5.0-50.0 ng/mL, respectively. The established UPLC-MS/MS method successfully identified all target analytes in ATM, and the phytochemicals were 0.01-67.98 mg/g in its lyophilized water extract.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.04a
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• pp.102-102
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• 2019

This study developed a HPLC analysis method for the determination of avicularin (AL) and quercitrin (QT) in Astilbe chinensis by HPLC. HPLC was performed on a Capcell Pak C18 MGII column ($4.6{\times}250mm$, $5{\mu}m$) with a gradient elution of 0.05% (v/v) trifluoroacetic acid (TFA) and acetonitrile at a flow rate of 1.0 mL/min at $30^{\circ}C$ and a UV detection wavelength of 254 nm. The analytical method was validated for its specificity, precision, accuracy, and linearity. The limits of detection and quantitation were AL 0.09 and 0.28 mg/mL, QT 0.03 and 0.09 mg/mL respectively. Calibration curves showed good linearity (AL r2 > 0.99990 and QT r2 > 0.99994), and the precision of analysis was satisfied (less than AL 0.59%, QT 0.63%). Recoveries of quantified compounds ranged from AL 100.57 to 102.08%, QT 99.94 to 100.64%. These results indicate that the developed HPLC method was applied successfully to the detection of AL and QT in A. chinensis.

• Korean Journal of Pharmacognosy
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• v.50 no.2
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• pp.133-140
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• 2019

In our previous study, we found uracil, adenosine, protocatechuic acid, syringin (eleutheroside B) and scoparone (6, 7-dimethoxycoumarin) in the Oplopanax elatus Nakai Stem. High-performance liquid chromatography (HPLC) -UV was used to quality and quantify the internal marker compounds in the O. elatus extract after validation of method with linearity, limit of detection (LOD), limit of quantitation (LOQ), accuracy and precision. The specificity assessment visually confirmed that the substance was detected without the introduction of other substances. The established method showed high linearity of the calibration curve and coefficient of correlation ($R^2$) of over the 0.999. HPLC was reported as five standard compounds equivalent using the following linear equation based on the calibration curve. The accuracy of measurement was 84.34 ~ 119.74% and the relative standard deviation (RSD) value was 0.28 ~ 1.60%. In addition, our established method showed high repeatability. The RSD value was 1.10 ~ 6.81%. So, we found the amount of the internal marker compounds in the O. elatus extract. These results demonstrated that can be used to quality evaluation of the O. elatus.