• Title/Summary/Keyword: liquid-liquid extraction (LLE)

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Determination of finasteride in human serum by LC-MS/MS (LC-MS/MS를 이용한 혈청 중 finasteride 분석)

  • Nam, Hye-Seon;Nam, Kyong-Hee;Jung, Su-Hee;Lee, Jang-Woo;Kang, Jin-Yeong;Hong, Soon-Keun;Kim, Tae-Sung;Kang, Tae-Seok;Yoon, Hae-Jung;Lee, Kwang-Ho;Rhee, Gyu-Seek
    • Analytical Science and Technology
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    • v.24 no.5
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    • pp.345-351
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    • 2011
  • A liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI/MS/MS) method was developed and validated for the determination of finasteride in human serum. Beclomethasone was used as internal standard (IS) and liquid-liquid extraction (LLE) using methyl tert-butyl ether (MTBE) was carried out to isolate analyte. The mass transitions monitored in multiple reaction monitoring (MRM) in positive ion mode were m/z 373.2${\rightarrow}$305.2 for finasteride and m/z 409.3${\rightarrow}$391.2 for IS. Retention times of finasteride and IS were 5.81 and 5.46 min, respectively. The limit of quantitation (LOQ) was 0.1 ng/mL and the calibration curve showed good linearity in the range of 0.1~20.0 ng/mL ($R^2$=0.9997). The intra-day assay precision and accuracy were in the range 6.3~10.6% and 97.3~103.6%, respectively, and the inter-day assay precision and accuracy were in the range 0.8~5.2% and 99.8~102.5%, respectively. The sample extract recovery of the method was 80~83%.

Analysis of dutasteride in human serum by LC-MS/MS (LC-MS/MS를 이용한 혈청 중 dutasteride 분석)

  • Nam, Hye-Seon;Nam, Kyong-Hee;Jung, Su-Hee;Lee, Jang-Woo;Kang, Jin-Yeong;Hong, Soon-Keun;Kim, Tae-Sung;Jung, Ki-Kyung;Kang, Tae-Seok;Yoon, Hae-Jung;Lee, Kwang-Ho;Rhee, Gyu-Seek
    • Analytical Science and Technology
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    • v.25 no.1
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    • pp.76-82
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    • 2012
  • The determination and confirmation of dutasteride in human serum was performed by a liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI/MS/MS). Beclomethasone as an internal standard (I.S.) was added to the serum and the mixed sample was pretreated by liquid-liquid extraction (LLE) with methyl tert-butyl ether (MTBE). The mass transitions of dutasteride and I.S. monitored in multiple reaction monitoring (MRM) were m/z 529.6${\rightarrow}$461.5 and m/z 409.3${\rightarrow}$391.2, respectively, and the retention times were 6.45 and 5.46 min, respectively. The calibration curve was linear in the concentration range of 0.5~30.0 ng/mL ($R^2$= 0.9999) and the limit of quantitation (LOQ) was found to be 0.5 ng/mL. The recovery of dutasteride was shown to be 66~72%. The intra-day assay precision and accuracy were in the range 3.5~5.5% and 85.7~89.9%, respectively, and the interday assay precision and accuracy were in the range 4.2~5.8% and 90.8~95.8%, respectively.

Determinations of Toltrazuril and Toltrazuril Sulfone Levels in Olive Flounder Paralichthys olivaceus Samples Using Liquid Chromatography-Electrospray Ionization Tandem Mass Spectrometry (LC-MS/MS를 이용한 넙치(Paralichthys olivaceus)시료의 톨트라주릴 및 톨트라주릴 설폰 분석)

  • Hong, Do Hee;Kim, Ah Hyun;Lee, Ka Jeong;Yoon, Minchul;Son, Kwang Tae;Kim, Myoung Sug;Kim, Na Young;Jung, Sung Hee;Jo, Mi Ra
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.52 no.5
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    • pp.461-467
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    • 2019
  • Several studies investigating the prevention and treatment of external parasites in farmed olive flounder Paralichthys olivaceus have found that the anticoccidial agent toltrazuril sulfone is an effective antiparasitic. Prior to undertaking a full-scale study, we developed analytical methods to detect the levels of toltrazuril and toltrazuril sulfone in farmed flounder samples using liquid chromatography-electrospray ionization tandem mass spectrometry (LC-MS/MS). This analysis showed that LC-MS/MS changed the mobile phase and collision energy of toltrazuril and toltrazuril sulfone. This was validated using established conditions. Sample pre-treatment for this process involved extraction with dichloromethane and purification by liquid-liquid extraction in formic acid, acetonitrile, and h-hexane, followed by determination of all compounds by LC-MS/MS. Separation was achieved within 10 min by gradient elution using a Capcell Pak C18 ($3.0{\mu}m$, $100{\times}2.0mm$) analytical column (Shiseido UG 120V) with a mixture of 0.1% (v/v) formic acid and acetonitrile. Multiple reaction monitoring was used for selective detection of toltrazuril and toltrazuril sulfone. This method yields satisfactory results for linearity, precision, and limits of quantification. Therefore, the method established in our study will serve as a basis for further research on parasite control by toltrazuril and toltrazuril sulfone.

Rapid and Simple Analytical Method for Removing Patulin from Apple Juice Using Solid Phase Extraction (고체상 추출법(SPE: Solid Phase Extraction)을 이용한 국내 사과주스 중 Patulin 간편.신속 분석방법)

  • Yim, Jong-Gab;Jang, Hae-Won;Lee, Kwang-Geun
    • Korean Journal of Food Science and Technology
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    • v.42 no.3
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    • pp.257-262
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    • 2010
  • Patulin, a secondary metabolite of mold, is commonly found in rotten apples. Many countries regulate patulin at levels ranging from 30 to $50\;{\mu}g/L$. Most analytical methods for removing patulin from apple juice include liquid-liquid extraction (LLE), which is time and labor intensive. To replace the LLE method, a solid-phase extraction (SPE) method has been developed for apple juice and unfiltered apple juice. A portion of the test sample was applied to a macroporous copolymer cartridge and washed with 5 mL of 1% sodium bicarbonate, followed by 5 mL of 1% acetic acid. Patulin was eluted with 5 mL of 2% acetonitrile in anhydrous ethyl ether. The mobile phase was tetrahydrofuran in water (0.8:99.2) and was detected with a UV detector at 276 nm. Recoveries ranged from 95 to 101% in test samples, and the minimum detectable level was 30 ppb. Because this SPE method is fast, easy, reliable, and inexpensive, it could be applicable for companies or analytical agencies to analyze patulin concentrations in apple juice.

Determination of ibuprofen and its metabolites in human urine by GC-MS (GC-MS에 의한 소변 중 Ibuprofen의 대사체 규명 및 대사 연구)

  • Yu, Dae-Hyung;Cho, Jung-Hum;Hong, Jong-Ki
    • Analytical Science and Technology
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    • v.23 no.2
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    • pp.179-186
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    • 2010
  • The oxidative metabolism of ibuprofen in healthy male urine collected at 3, 6, 9, 12 and 15 h after oral administration of ibuprofen was studied by GC/MS assay. To detect conjugated metabolites of ibuprofen, urine sample was acid-hydrolyzed with 6 M HCl at $100^{\circ}C$ for 30 min. To effectively extract ibuprofen and its metabolites, liquid-liquid extraction (LLE) was conducted at pH 3, 5, and 7, respectively. As a result, LLE at pH 3 was shown to be the best extraction condition. For the determination of trace amounts of ibuprofen and its metabolites in extract, trimethylsilylation (TMS) with BSTFA was applied and followed by GC/MS analysis. In this study, main 5 metabolites including parent drug were detected and these metabolites were assigned as three hydroxylated forms and one carboxylated form. Each metabolite was tentatively identified by both interpretation of mass spectrum and comparison with previously reported results. In addition, time profile of urinary excretion rate for parent drugs and metabolites was studied. Finally, the metabolic pathways of ibuprofen were suggested on the basis of the structural elucidation of its metabolites and excretion profiles.

Development of an analytical method of organochlorine pesticides in human bloods using head space-solid phase microextraction coupled with gas chromatography/mass spectrometry (HS SPME-GC/MS를 이용한 혈액 중 유기염소계 농약의 분석법 개발)

  • Kang, Tae-Woo;Pyo, Hee-Soo;Hong, Jong-Ki
    • Analytical Science and Technology
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    • v.21 no.4
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    • pp.259-271
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    • 2008
  • The analytical method of extracting compounds from human blood to examine accumulated organochlorine pesticides (OCPs) has been widely used the traditional liquid-liquid extraction (LLE) method and solid-phase extraction (SPE) method, yet these methods have certain limitations in purification and usafe of a large amount of sample. In order to overcome the se problems reside in these, solid-phase microextraction (SPME), known as a highly efficient extration method with less samples and relatively simple, was employed to collect 18 different kinds of OCPs in blood as extraction method in this study. To optimize extraction method, we examine various experimental SPME-parameters such as adsorption (fiber type, adsorption time, adsorption temperature, salting out effect), and desorption (desorption time, desorption temperature etc.). From the experimental results, the optimal conditions are as follows: fiber was polyacrylate with $85{\mu}m$, adsorption time was for 5 min, adsorption optimum temperature was at $280^{\circ}C$, and salting out effect was NaCl with 0.1 g. MDL, precision and accuracy was in the ranges of 0.05~0.20 ng/mL, 5.59~13.39%, respedively, and accuracy was -0.5% ~24.5% for all OCPs.

An extraction method and residues of benzimidazole fungicides in soybean sprouts (콩나물중 benzimidazole계 농약의 추출방법과 잔류성)

  • Park, Jun-Jo;Yong, Kum-Chan;Jeung, Jin-A
    • The Korean Journal of Pesticide Science
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    • v.4 no.1
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    • pp.26-31
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    • 2000
  • An analytical method was approached to determine the residues of benzimidazole fungicides in soybean sprouts and was compared with traditional solvent-based method of extraction, solid phase extraction(SPE) and matrix solid phase dispersion(MSPD). The recoveries of carbendazim for liquid-liquid extraction (LLE), SPE and MSPD in soybean sprouts were $69.25{\sim}79.16$, $79.99{\sim}90.42$ and $92.40{\sim}98.48%$, respectively. The recoveries of thiabendazole for LLE, SPE and MSPD in soybean sprouts were $64.86{\sim}83.26$, $79.12{\sim}94.04$ and $65.44{\sim}73.92%$, respectively. The residues of carbendazim by elapsed time under our cultivated soybean sprouts program found $0.10{\sim}0.25$ mg/kg after 5 days and trace concentration of carbendazim was detected after 7 days. Of the 448 samples analyzed, less than 1.5% had residues of carbendazim ranged from 0.05 to 0.37 mg/kg.

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Determination of Residue Levels of Ethyl Carbamate in Alcoholic Beverages by Gas Chromatography/Tandem Mass Spectrometry (GC/MS/MS) (가스크로마토그래피/질량분석기(GC/MS/MS)를 이용한 주류 중 에틸카바메이트 잔류량 조사)

  • Kim, Dong-Ho;Jang, Han-Sub;Choi, Gu-Il;Kim, Hyun-Jung;Kim, Ho-Jin;Kim, Hyo-Lin;Kim, Keun-Sung
    • Journal of Food Hygiene and Safety
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    • v.28 no.1
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    • pp.63-68
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    • 2013
  • Ethyl carbamate (EC) is a contaminant generated in the fermentation processes of various fermented foods. In this study, residue levels of EC in 95 alcoholic beverage samples were determined by using Gas Chromatography/Tandem Mass Spectrometry (GC/MS/MS). All the samples were purified by a liquid-liquid extraction (LLE) method using dichloromethane. The LLE method enables an improvement in time and cost to detection and specificity over the conventional extraction methods. The limits of detection and quantification (LOD and LOQ) to analyze EC were 1.3 and 4.0 ng/mL, respectively. The recovery rates of EC were ranged from 90.0 to 97.5% at the levels of 50, 100, and 500 ug/L. Among traditional grain-based alcoholic beverage samples (n = 34), the average residue levels of EC in takju, yakju, and cheongju were 0.63, 7.01, and 14.11 ug/L, respectively. Among fruit-based alcoholic beverage samples (n = 48), those of EC in japanese apricot spirits, bokbunjaju, grape wines, and other fruit wines were 79.18, 1.66, 2.64, and 2.39 ug/L, respectively. Among distilled or diluted alcoholic beverage samples (n = 13), those of EC in soju (distilled or diluted), general distillates, liquors, and brandies were 0, 3.30, 8.20, and 8.52 ug/L, respectively. Therefore, this study reports that the residue levels of EC in the alcoholic beverages, distributed in the current domestic markets, did not reach its maximum allowed levels of 30 and 400 ug/L established for grape and fruit wines in Canada, respectively.

Simultaneous Determination and Monitoring of Bisphenols in River Water using Gas Chromatography-Mass Spectrometry (GC-MS 를 이용한 하천수 중 Bisphenol계 화합물의 동시분석 및 모니터링)

  • Kim, Jihyun;Choi, Jeong-Heui;Kang, Tae-Woo;Kang, Taegu;Hwang, Soon-Hong;Shim, Jae-Han
    • Korean Journal of Environmental Agriculture
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    • v.36 no.3
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    • pp.154-160
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    • 2017
  • BACKGROUND:This study was carried out to establish an efficient sample preparation for the simultaneous determination of bisphenols (BPs) in river water samples using gas chromatography-mass spectrometry (GC-MS). Sample preparation was examined with conventional extraction methods, such as solid-phase extraction (SPE) and liquid-liquid extraction (LLE), and their efficiency was compared with validation results, including linearity of calibration curve, method detection limit (MDL), limit of quantification (LOQ), accuracy, and precision. METHODS AND RESULTS:The BPs (bisphenol A, BPA; bisphenol B, BPB; bisphenol C, BPC; bisphenol E, BPE; bisphenol F, BPF; bisphenol S, BPS) were analyzed using GC-MS. The range of MDLs by SPE and LLE methods was $0.0005{\sim}0.0234{\mu}g/L$ and $0.0037{\sim}0.2034{\mu}g/L$, and that of LOQs was $0.0015{\sim}0.0744{\mu}g/L$ and $0.0117{\sim}0.6477{\mu}g/L$, respectively. The calibration curve obtained from standard solution of $0.004{\sim}4.0{\mu}g/L$ (SPE) and $0.016{\sim}16{\mu}g/L$ (LLE) showed good linearity with $r^2$ value of 0.9969 over. Accuracy was 93.2~108% and 97.4~120%, and precision was 1.7~4.6% and 0.7~6.5%, respectively. The values of MDL and LOQ resulted from the SPE method were higher than those from the LLE method, particularly those values of BPA were highest among the BPs. Based on the results, the SPE method was applied to determine the BPs in river water samples. Water samples were collected from mainstream, tributary and sewage wastewater treatment plants (SWTPs) in the Yeongsan river basin. The concentration of BPB, BPC, BPE, BPF and BPS were not detected in all sites, whereas BPA was ranged $0.0095{\sim}0.2583{\mu}g/L$, which was $0.0166{\sim}0.0810{\mu}g/L$ for mainstreams, $0.0095{\sim}0.2583{\mu}g/L$ for tributaries, $0.0352{\sim}0.1217{\mu}g/L$ for SWTPs. CONCLUSION: From these results, the SPE method was very effective for the simultaneous determination of BPs in river water samples using GC-MS. We provided that it is a convenient, reliable and sensitive method enough to monitor and understand the fate of the BPs in aquatic ecosystems.

Determination of homogentisic acid in human plasma by GC-MS for diagnosis of alkaptonuria (GC-MS를 이용한 혈장 중 호모겐티식산의 분석;알캅톤뇨증의 진단)

  • Thapa, Maheshwor;Yu, Jundong;Lee, Wonjae;Islam, Fokhrul;Yoon, Hye-Ran
    • Analytical Science and Technology
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    • v.28 no.5
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    • pp.323-330
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    • 2015
  • Alkaptonuria, a rare inherited metabolic disease, is characterized by a lack of homogentisate dioxygenase and accumulation of homogentisic acid (HGA), leading to homogentisic aciduria, arthritis, and ochronosis. In this study, a rapid analytical method, without an expensive and tedious solid phase extraction step, was developed to quantify HGA in plasma using GC-MS. HGA-spiked pooled plasma samples were subjected to liquid-liquid extraction (LLE) with ethyl acetate, followed by trimethylsilyl derivatization (TMS) and GC-MS quantification using selected ion monitoring. The formation of TMS derivative of the 1 carboxylic and 2 hydroxyl functional groups was performed by reacting BSTFA (with 10% TMCS) for 5 min at 80 ℃. For selected ion monitoring, quantification and confirmation ions were determined based on specific ions (m/z 384, m/z 341 and m/z 252) of the TMS derivative of HGA. Calibration curves of pooled normal plasma specimens showed a linear relationship in the range of 1-100 ng/µL. The precision and accuracy were within a relative standard deviation (RSD) of 1 to 15% and a bias of -5 to 25%. Recoveries were obtained in the range of 99-125% and 95-115% for intra-day and inter-day assay, respectively, at 2, 20 and 80 ng/µL. The limit of detection (LOD) and limit of quantification (LOQ) were 0.4 ng/µL and 4 ng/µL, respectively. No homogentisic acid was excreted from normal Korean plasma samples. Collectively, the results from the present study suggest that this method could be useful for routine diagnosis and therapeutic monitoring of alkaptonuria patients with excellent sensitivity and rapidity.