1
|
Jin HF, Shi Y, Jiao YH, Fei TH, Cao J, Ye LH. Two-step pressure injection-assisted online enrichment of herbicides from foods with affinity micelle sweeping by micellar electrokinetic chromatography. J Chromatogr A 2023; 1706:464258. [PMID: 37544236 DOI: 10.1016/j.chroma.2023.464258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2023] [Revised: 07/09/2023] [Accepted: 07/28/2023] [Indexed: 08/08/2023]
Abstract
A novel online two-step pressure injection-assisted stacking preconcentration method, which involves sweeping and affinity micelles in micellar electrokinetic chromatography was developed to simultaneously measure various organic anions. The micellar solution was a mixed solution that contained 0.3 mM didodecyldimethylammonium bromide and 20 mM borax. After the micellar solution was injected for 60 s, the tested analytes prepared in 20 mM borax were introduced into the capillary for 150 s. The key experimental factors that influenced the separation and sensitivity were investigated and optimized, including the concentration and injection time of the micellar solution, the concentration of borax in the sample solution, the concentration of sodium dodecyl sulfate and borax in the background electrolyte (BGE), the content of acetonitrile in the BGE and the injection time of the sample solution. Compared with typical injection methods, this method achieved sensitivity enhancement factors ranging from 85 to 97 under optimized conditions. Good linearity for matrix-matched calibration was established for all analytes with R2 values of 0.9986-0.9996. The intraday (n = 6) and interday (n = 6) precisions of the method were less than 2.85% when expressed as relative standard deviations. When the method was applied to analyze rice and dried ginger samples, analyte recoveries ranged from 85.81% to 106.59%. Through sweeping and affinity micelles, stacking preconcentration method was successfully employed to analyze trace amounts of fenoprop and 2,4-dichlorophenoxyacetic acid in rice and dried ginger samples.
Collapse
Affiliation(s)
- Huang-Fei Jin
- College of Material Chemistry and Chemical Engineering, Hangzhou Normal University, Hangzhou 311121, China
| | - Ying Shi
- College of Material Chemistry and Chemical Engineering, Hangzhou Normal University, Hangzhou 311121, China
| | - Yan-Hua Jiao
- College of Material Chemistry and Chemical Engineering, Hangzhou Normal University, Hangzhou 311121, China
| | - Ting-Hong Fei
- College of Material Chemistry and Chemical Engineering, Hangzhou Normal University, Hangzhou 311121, China
| | - Jun Cao
- College of Material Chemistry and Chemical Engineering, Hangzhou Normal University, Hangzhou 311121, China.
| | - Li-Hong Ye
- Department of Traditional Chinese Medicine, Hangzhou Red Cross Hospital, Hangzhou 310003, PR China.
| |
Collapse
|
2
|
Pseudophase microextraction for in-line sample concentration in micellar electrokinetic chromatography. Anal Chim Acta 2022; 1189:339219. [PMID: 34815031 DOI: 10.1016/j.aca.2021.339219] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 09/15/2021] [Accepted: 10/23/2021] [Indexed: 12/31/2022]
Abstract
Pseudophase microextraction (PPME) as a simple in-line sample concentration technique in micellar electrokinetic chromatography (MEKC) is presented. In contrast to popular electric-field driven stacking techniques in MEKC such as sweeping, PPME is pressure-driven. The technique afforded up to 403-2968x improvements in peak heights for fenoprop, dichlorprop, 1- and 2-naphthol compared to typical injection. Under the same MEKC conditions, the improvements in PPME were up to 23-59x better compared to sweeping. Briefly in PPME, the entire capillary was loaded (up to 20 capillary volumes) with the sample prepared in a dilute solution of cetyltrimethylammonium bromide ([CTAB] > critical surface aggregation concentration). The CTAB formed aggregates at the inner capillary walls and these aggregates acted as a stationary chromatographic pseudophase. After clean-up via flushing the capillary with purified water, the MEKC background solution (BGS) with sodium dodecyl sulfate was then introduced by pressure from the outlet end to elute the retained analytes. The analytes concentrate at front of the BGS and the front was moved to the inlet end of the capillary prior to MEKC. Optimization strategies and current limitations in PPME-MEKC are described. The linear ranges using a 4 capillary volume sample load obtained for fenoprop, dichlorprop, 1- and 2-naphthol were between 1 and 160 ng/mL (r2s ≥ 0.996), LOQs = 1-2.5 ng/mL and repeatability %RSDs (n = 6) were ≤5% (intra-day) and ≤7% (inter-day) (using low analyte concentrations 1-5x LOQ). PPME-MEKC with simple dilution of fortified real samples (no off-line sample concentration) was also able to detect low levels of dichlorprop (10 ng/mL, limit set in Australia) and 1- and 2-naphthol (7.5-15 ng/mL) in a drinking water and natural water sample, respectively (% recovery = 84-108%). The concept of PPME may find use in other modes of capillary electrophoresis and other nano-microscale separations.
Collapse
|
3
|
Ranasinghe M, Karunaratne H, Quirino JP. Sweeping-micellar electrokinetic chromatography versus reversed phase liquid chromatography for the determination of coumarin in curry. J Chromatogr A 2021; 1657:462586. [PMID: 34689906 DOI: 10.1016/j.chroma.2021.462586] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2021] [Revised: 09/13/2021] [Accepted: 09/26/2021] [Indexed: 11/18/2022]
Abstract
Coumarin is a phytotoxin found in the popular spice cinnamon, which is used to flavor many Asian curry dishes. In this work, we developed and compared the analytical performance of reversed-phase liquid chromatography (RP-LC) and sweeping-micellar electrokinetic chromatography (MEKC) methods for the determination of coumarin in complex curry (gravy) samples. Using a matrix matched sample (curry after solvent extraction with methanol and diluted with 100 mM phosphoric acid), the intra-day and inter-day repeatability of retention/migration time and (corrected) peak area for both methods were acceptable (%RSD (n=6) ≤ 5%). The linear range and limit of quantitation (LOQ) were an order of magnitude better in RP-LC (RP-LC linear range = 0.11-108 mg/kg, LOQ = 0.11 mg/kg) (Sweeping-MEKC linear range = 2.16-216 mg/kg, LOQ = 2.16 mg/kg). However, the limit of detection (S/N=3) and LOQ in sweeping-MEKC was 0.65 mg/kg and 2.16 mg/kg, which were sufficient to report the levels of coumarin ≥ the European limit of 2 mg/kg in foods. During the analysis of 25 curry samples, relatively similar results for sweeping-MEKC and RP-LC were obtained for 6 samples that contained coumarin >LOQ of sweeping-MEKC. Interferences in RP-LC lead to significant overestimation of coumarin levels in 3 samples. Coumarin levels above the EU limit was found in 6 curry samples using the more selective sweeping-MEKC. This work should also raise public awareness on the presence of potentially high levels of coumarin in some foods.
Collapse
Affiliation(s)
- Muhandiramge Ranasinghe
- Australian Centre for Research on Separation Science, School of Natural Sciences-Chemistry, University of Tasmania, Hobart, Tasmania 7001, Australia
| | - Hiranya Karunaratne
- Australian Centre for Research on Separation Science, School of Natural Sciences-Chemistry, University of Tasmania, Hobart, Tasmania 7001, Australia
| | - Joselito P Quirino
- Australian Centre for Research on Separation Science, School of Natural Sciences-Chemistry, University of Tasmania, Hobart, Tasmania 7001, Australia.
| |
Collapse
|
4
|
Dang HNP, Quirino JP. Analytical Separation of Carcinogenic and Genotoxic Alkenylbenzenes in Foods and Related Products (2010-2020). Toxins (Basel) 2021; 13:toxins13060387. [PMID: 34071244 PMCID: PMC8228529 DOI: 10.3390/toxins13060387] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 05/21/2021] [Accepted: 05/21/2021] [Indexed: 11/16/2022] Open
Abstract
Alkenylbenzenes are potentially toxic (genotoxic and carcinogenic) compounds present in plants such as basil, tarragon, anise star and lemongrass. These plants are found in various edible consumer products, e.g., popularly used to flavour food. Thus, there are concerns about the possible health consequences upon increased exposure to alkenylbenzenes especially due to food intake. It is therefore important to constantly monitor the amounts of alkenylbenzenes in our food chain. A major challenge in the determination of alkenylbenzenes in foods is the complexity of the sample matrices and the typically low amounts of alkenylbenzenes present. This review will therefore discuss the background and importance of analytical separation methods from papers reported from 2010 to 2020 for the determination of alkenylbenzenes in foods and related products. The separation techniques commonly used were gas and liquid chromatography (LC). The sample preparation techniques used in conjunction with the separation techniques were various variants of extraction (solvent extraction, liquid-liquid extraction, liquid-phase microextraction, solid phase extraction) and distillation (steam and hydro-). Detection was by flame ionisation and mass spectrometry (MS) in gas chromatography (GC) while in liquid chromatography was mainly by spectrophotometry.
Collapse
|
5
|
Yu RB, Quirino JP. Ionic liquids in electrokinetic chromatography. J Chromatogr A 2020; 1637:461801. [PMID: 33385743 DOI: 10.1016/j.chroma.2020.461801] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 12/11/2020] [Accepted: 12/12/2020] [Indexed: 01/22/2023]
Abstract
There is an interest in the application of ionic liquids as additives into the separation media to improve achiral and chiral separations in electrokinetic chromatography (EKC). This review will critically discuss the developments on the use of ionic liquids in the different modes of EKC during the last five years (2015-mid 2020). A healthy number of 48 research articles searched through Scopus were categorised into two: ionic liquids as sole pseudophase (micelles, microemulsions, ligand exchange pseudophase or molecular pseudophase) and ionic liquids with pseudophase (achiral or chiral). More than half of the papers dealt with chiral separations that were mostly facilitated by another additive or pseudophase. The role of ionic liquids for improvement of separations were analysed, and we provided some recommendations for further investigations. Finally, the use of ionic liquids in different on-line sample concentration or stacking methods (i.e., field enhancement and sweeping) was briefly discussed.
Collapse
Affiliation(s)
- Raymond B Yu
- Australian Centre for Research on Separation Science (ACROSS), School of Natural Sciences-Chemistry, University of Tasmania, Hobart, Tasmania 7001, Australia
| | - Joselito P Quirino
- Australian Centre for Research on Separation Science (ACROSS), School of Natural Sciences-Chemistry, University of Tasmania, Hobart, Tasmania 7001, Australia.
| |
Collapse
|
6
|
Open-tubular admicellar electrochromatography of charged analytes. Talanta 2020; 208:120401. [PMID: 31816751 DOI: 10.1016/j.talanta.2019.120401] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 09/26/2019] [Accepted: 09/27/2019] [Indexed: 11/23/2022]
Abstract
Fundamental studies on the separation of cationic and anionic analytes in open-tubular admicellar electrochromatography (OT-AMEC) using cetyltrimethylammonium bromide (CTAB) and fused silica capillaries are presented. OT-AMEC was compared with open-tubular admicellar liquid chromatography (OT-AMLC) by running the two methods using the same mobile phases. The mobile phases were buffered at pH ≥ 6 and contained a low concentration (above the critical surface aggregation concentration and below the critical micelle concentration) of CTAB. The stationary pseudophase of CTAB admicelles were formed at the solid surface and liquid interface inside the capillary by simply conditioning the capillary with the mobile phase. Separations were performed in a 30 cm (21.5 cm to UV detector) long and 50 μm inner diameter capillary, using low pressure (50 mbar) in OT-AMLC and high voltage (15 kV at negative polarity) in OT-AMEC. The appropriate equations for the experimental estimation of retention factor (k) values of analytes were discussed. For anionic analytes, k in OT-AMEC were carefully determined by considering the observed interaction between CTAB monomers and tested analytes. The calculated k for each analyte was found similar in OT-AMLC and OT-AMEC, although the mechanism of retention was not entirely different due to the contribution of electrophoresis in OT-AMEC. Studies on the addition of a typical (i.e., acetonitrile) and atypical modifier (i.e., nonyl-β-glucoside) into the mobile phase, and sample focusing with >10x improvement in peak height under isocratic conditions were also conducted.
Collapse
|
7
|
Debruille K, Smith JA, Quirino JP. Pressurized Hot Water Extraction and Capillary Electrophoresis for Green and Fast Analysis of Useful Metabolites in Plants. Molecules 2019; 24:molecules24132349. [PMID: 31247895 PMCID: PMC6651437 DOI: 10.3390/molecules24132349] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Revised: 06/21/2019] [Accepted: 06/25/2019] [Indexed: 12/02/2022] Open
Abstract
The search for useful compounds from plants is an important research area. Traditional screening that involves isolation and identification/quantitation is tedious, time consuming, and generates a significant amount of chemical waste. Here, we present a simple, fast, and green strategy to assess ≥0.1% wt/wt quantities of useful compounds in plants/spices using pressurized hot water extraction using a household espresso machine followed by chemical analysis using capillary electrophoresis. Three demonstrations with polygodial, cinnamaldehyde, coumarin, and shikimic acid as target metabolites are shown. Direct analysis of extracts was by the developed micellar electrokinetic chromatography and capillary zone electrophoresis methods. The approach, which can be implemented in less developed countries, can process many samples within a day, much faster than traditional techniques that would normally take at least a day. Finally, 0.8–1.1% wt/wt levels of shikimic acid were found in Tasmanian-pepperberry and Tasmanian-fuschia leaves via the approach.
Collapse
Affiliation(s)
- Kurt Debruille
- Australian Centre for Research on Separation Science (ACROSS), School of Natural Sciences-Chemistry, University of Tasmania, Private Bag 75, Hobart, 7001 Tasmania, Australia
- Department of Chemistry, Faculty of Science, University of Mons, 20 Place du Parc, 7000 Mons, Belgium
| | - Jason A Smith
- School of Natural Sciences-Chemistry, University of Tasmania, Private Bag 75, Hobart, 7001 Tasmania, Australia
| | - Joselito P Quirino
- Australian Centre for Research on Separation Science (ACROSS), School of Natural Sciences-Chemistry, University of Tasmania, Private Bag 75, Hobart, 7001 Tasmania, Australia.
| |
Collapse
|
8
|
Chiral Selectors in Capillary Electrophoresis: Trends During 2017⁻2018. Molecules 2019; 24:molecules24061135. [PMID: 30901973 PMCID: PMC6471358 DOI: 10.3390/molecules24061135] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Revised: 03/16/2019] [Accepted: 03/19/2019] [Indexed: 01/10/2023] Open
Abstract
Chiral separation is an important process in the chemical and pharmaceutical industries. From the analytical chemistry perspective, chiral separation is required for assessing the fit-for-purpose and the safety of chemical products. Capillary electrophoresis, in the electrokinetic chromatography mode is an established analytical technique for chiral separations. A water-soluble chiral selector is typically used. This review therefore examines the use of various chiral selectors in electrokinetic chromatography during 2017–2018. The chiral selectors were both low and high (macromolecules) molecular mass molecules as well as molecular aggregates (supramolecules). There were 58 papers found by search in Scopus, indicating continuous and active activity in this research area. The macromolecules were sugar-, amino acid-, and nucleic acid-based polymers. The supramolecules were bile salt micelles. The low molecular mass selectors were mainly ionic liquids and complexes with a central ion. A majority of the papers were on the use or preparation of sugar-based macromolecules, e.g., native or derivatised cyclodextrins. Studies to explain chiral recognition of macromolecular and supramolecular chiral selectors were mainly done by molecular modelling and nuclear magnetic resonance spectroscopy. Demonstrations were predominantly on drug analysis for the separation of racemates.
Collapse
|
9
|
Wuethrich A, Quirino JP. A decade of microchip electrophoresis for clinical diagnostics - A review of 2008-2017. Anal Chim Acta 2018; 1045:42-66. [PMID: 30454573 DOI: 10.1016/j.aca.2018.08.009] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 07/30/2018] [Accepted: 08/03/2018] [Indexed: 01/10/2023]
Abstract
A core element in clinical diagnostics is the data interpretation obtained through the analysis of patient samples. To obtain relevant and reliable information, a methodological approach of sample preparation, separation, and detection is required. Traditionally, these steps are performed independently and stepwise. Microchip capillary electrophoresis (MCE) can provide rapid and high-resolution separation with the capability to integrate a streamlined and complete diagnostic workflow suitable for the point-of-care setting. Whilst standard clinical diagnostics methods normally require hours to days to retrieve specific patient data, MCE can reduce the time to minutes, hastening the delivery of treatment options for the patients. This review covers the advances in MCE for disease detection from 2008 to 2017. Miniaturised diagnostic approaches that required an electrophoretic separation step prior to the detection of the biological samples are reviewed. In the two main sections, the discussion is focused on the technical set-up used to suit MCE for disease detection and on the strategies that have been applied to study various diseases. Throughout these discussions MCE is compared to other techniques to create context of the potential and challenges of MCE. A comprehensive table categorised based on the studied disease using MCE is provided. We also comment on future challenges that remain to be addressed.
Collapse
Affiliation(s)
- Alain Wuethrich
- Centre for Personalised Nanomedicine, Australian Institute for Bioengineering and Nanotechnology (AIBN), University of Queensland, Building 75, Brisbane, QLD, 4072, Australia
| | - Joselito P Quirino
- Australian Centre for Research on Separation Science (ACROSS), School of Physical Sciences-Chemistry, University of Tasmania, Private Bag 75, Hobart, TAS, 7001, Australia.
| |
Collapse
|
10
|
Adam V, Vaculovicova M. CE and nanomaterials - Part II: Nanomaterials in CE. Electrophoresis 2017; 38:2405-2430. [DOI: 10.1002/elps.201700098] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Revised: 07/04/2017] [Accepted: 07/05/2017] [Indexed: 12/23/2022]
Affiliation(s)
- Vojtech Adam
- Department of Chemistry and Biochemistry; Mendel University in Brno; Brno Czech Republic
- Central European Institute of Technology; Brno University of Technology; Brno Czech Republic
| | - Marketa Vaculovicova
- Department of Chemistry and Biochemistry; Mendel University in Brno; Brno Czech Republic
- Central European Institute of Technology; Brno University of Technology; Brno Czech Republic
| |
Collapse
|
11
|
Godyń J, Hebda M, Więckowska A, Więckowski K, Malawska B, Bajda M. Lipophilic properties of anti-Alzheimer's agents determined by micellar electrokinetic chromatography and reversed-phase thin-layer chromatography. Electrophoresis 2017; 38:1268-1275. [DOI: 10.1002/elps.201600473] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Revised: 02/02/2017] [Accepted: 02/02/2017] [Indexed: 11/09/2022]
Affiliation(s)
- Justyna Godyń
- Department of Physicochemical Drug Analysis; Jagiellonian University Medical College; Kraków Poland
| | - Michalina Hebda
- Department of Physicochemical Drug Analysis; Jagiellonian University Medical College; Kraków Poland
| | - Anna Więckowska
- Department of Physicochemical Drug Analysis; Jagiellonian University Medical College; Kraków Poland
| | - Krzysztof Więckowski
- Department of Organic Chemistry; Jagiellonian University Medical College; Kraków Poland
| | - Barbara Malawska
- Department of Physicochemical Drug Analysis; Jagiellonian University Medical College; Kraków Poland
| | - Marek Bajda
- Department of Physicochemical Drug Analysis; Jagiellonian University Medical College; Kraków Poland
| |
Collapse
|
12
|
El-Hady DA, Albishri HM, Wätzig H. Ionic liquids in enhancing the sensitivity of capillary electrophoresis: Off-line and on-line sample preconcentration techniques. Electrophoresis 2016; 37:1609-23. [DOI: 10.1002/elps.201600069] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Revised: 03/26/2016] [Accepted: 03/29/2016] [Indexed: 01/02/2023]
Affiliation(s)
- Deia Abd El-Hady
- Department of Chemistry, Faculty of Science; University of Jeddah; Jeddah Saudi Arabia
- Department of Chemistry, Faculty of Science; Assiut University; Assiut Egypt
| | - Hassan M. Albishri
- Department of Chemistry, Faculty of Science; King Abdulaziz University; Jeddah Saudi Arabia
| | - Hermann Wätzig
- Institute of Medicinal and Pharmaceutical Chemistry; TU Braunschweig; Braunschweig Germany
| |
Collapse
|
13
|
Kubalczyk P, Chwatko G, Głowacki R. Fast and simple MEKC sweeping method for determination of thiosulfate in urine. Electrophoresis 2015; 37:1155-60. [DOI: 10.1002/elps.201500411] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Revised: 10/05/2015] [Accepted: 10/08/2015] [Indexed: 11/09/2022]
Affiliation(s)
- Paweł Kubalczyk
- Department of Environmental Chemistry, Faculty of Chemistry; University of Łódź; Poland
| | - Grażyna Chwatko
- Department of Environmental Chemistry, Faculty of Chemistry; University of Łódź; Poland
| | - Rafał Głowacki
- Department of Environmental Chemistry, Faculty of Chemistry; University of Łódź; Poland
| |
Collapse
|
14
|
Li W, Zech I, Gieselmann V, Müller CE. A capillary electrophoresis method with dynamic pH junction stacking for the monitoring of cerebroside sulfotransferase. J Chromatogr A 2015; 1407:222-7. [DOI: 10.1016/j.chroma.2015.06.053] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2015] [Revised: 06/16/2015] [Accepted: 06/19/2015] [Indexed: 12/27/2022]
|
15
|
Interface-free two-dimensional heart-cutting capillary electrophoresis for the separation and stacking of anionic and neutral analytes. J Sep Sci 2015; 38:2532-7. [DOI: 10.1002/jssc.201500268] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Revised: 04/13/2015] [Accepted: 04/14/2015] [Indexed: 02/01/2023]
|
16
|
Kubalczyk P, Borowczyk K, Chwatko G, Głowacki R. Simple micellar electrokinetic chromatography method for the determination of hydrogen sulfide in hen tissues. Electrophoresis 2015; 36:1028-32. [DOI: 10.1002/elps.201400518] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Revised: 01/21/2015] [Accepted: 01/21/2015] [Indexed: 11/09/2022]
Affiliation(s)
- Paweł Kubalczyk
- Department of Environmental Chemistry; Faculty of Chemistry; University of Łódź; Poland
| | - Kamila Borowczyk
- Department of Environmental Chemistry; Faculty of Chemistry; University of Łódź; Poland
| | - Grażyna Chwatko
- Department of Environmental Chemistry; Faculty of Chemistry; University of Łódź; Poland
| | - Rafał Głowacki
- Department of Environmental Chemistry; Faculty of Chemistry; University of Łódź; Poland
| |
Collapse
|
17
|
Analysis of the Staphylococcus aureus capsule biosynthesis pathway in vitro: Characterization of the UDP-GlcNAc C6 dehydratases CapD and CapE and identification of enzyme inhibitors. Int J Med Microbiol 2014; 304:958-69. [DOI: 10.1016/j.ijmm.2014.06.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Revised: 05/30/2014] [Accepted: 06/01/2014] [Indexed: 12/25/2022] Open
|
18
|
Alkyl imidazolium ionic liquid based sweeping-micellar electrokinetic chromatography for simultaneous determination of seven tea catechins in human plasma. J Chromatogr B Analyt Technol Biomed Life Sci 2014; 969:224-9. [DOI: 10.1016/j.jchromb.2014.08.028] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2014] [Revised: 08/22/2014] [Accepted: 08/25/2014] [Indexed: 01/27/2023]
|
19
|
Abd El-Hady D, Albishri HM, Rengarajan R, Wätzig H. Use of short chain alkyl imidazolium ionic liquids for on-line stacking and sweeping of methotrexate, flinic acid and folic acid: Their application to biological fluids. Electrophoresis 2014; 35:1956-64. [DOI: 10.1002/elps.201400073] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2013] [Revised: 04/07/2014] [Accepted: 04/08/2014] [Indexed: 01/19/2023]
Affiliation(s)
- Deia Abd El-Hady
- Chemistry Department; Faculty of Science; King Abdulaziz University; North Jeddah Saudi Arabia
- Chemistry Department; Faculty of Science; Assiut University; Assiut Egypt
| | - Hassan M. Albishri
- Chemistry Department; Faculty of Science; King Abdulaziz University; Jeddah Saudi Arabia
| | - Rajesh Rengarajan
- Chemistry Department; Faculty of Science; King Abdulaziz University; Jeddah Saudi Arabia
| | - Hermann Wätzig
- Institute of Medicinal and Pharmaceutical Chemistry; Braunschweig Germany
| |
Collapse
|
20
|
Kukusamude C, Srijaranai S, Quirino JP. Stacking and Separation of Neutral and Cationic Analytes in Interface-Free Two-Dimensional Heart-Cutting Capillary Electrophoresis. Anal Chem 2014; 86:3159-66. [DOI: 10.1021/ac500090n] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- Chunyapuk Kukusamude
- Australian
Centre for Research on Separation Science, School of
Physical Sciences—Chemistry, University of Tasmania, Hobart 7001, Australia
- Materials Chemistry
Research Unit, Department of Chemistry and Center of Excellence
for Innovation in Chemistry, Faculty of Science, Khon Kaen University, Khon Kaen 40002, Thailand
| | - Supalax Srijaranai
- Materials Chemistry
Research Unit, Department of Chemistry and Center of Excellence
for Innovation in Chemistry, Faculty of Science, Khon Kaen University, Khon Kaen 40002, Thailand
| | - Joselito P. Quirino
- Australian
Centre for Research on Separation Science, School of
Physical Sciences—Chemistry, University of Tasmania, Hobart 7001, Australia
| |
Collapse
|
21
|
Rabanes HR, Guidote AM, Quirino JP. Micellar electrokinetic chromatography of the constituents in Philippine lagundi (Vitex negundo) herbal products. Microchem J 2014. [DOI: 10.1016/j.microc.2013.10.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
22
|
Wuethrich A, Haddad PR, Quirino JP. Chiral capillary electromigration techniques-mass spectrometry-hope and promise. Electrophoresis 2013; 35:2-11. [PMID: 24265218 DOI: 10.1002/elps.201300377] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2013] [Revised: 10/06/2013] [Accepted: 10/07/2013] [Indexed: 11/09/2022]
Abstract
Analytical methods for chiral compounds require a separation step prior to mass spectrometric detection. CE can separate enantiomers by the use of a chiral selector and can be hyphenated with MS. The chiral selector can be either embedded inside the capillary (electrochromatography) or added into the background solution (EKC). This review describes the fundamentals and highlights the recent developments (September 2009-May 2013) of chiral CEC and EKC with detection using MS. There were 20 research and more than 30 review papers during this period. The research efforts were driven by fundamental studies, such as the development of novel chiral selectors in electrochromatography and of advanced partial filling techniques in EKC in order to optimise separation. Other developments were in application studies, such as in food analytics and metabolomics.
Collapse
Affiliation(s)
- Alain Wuethrich
- Australian Centre for Research on Separation Science (ACROSS), School of Chemistry, University of Tasmania, Hobart, Australia
| | | | | |
Collapse
|
23
|
Electrokinetic removal of charged species from small sample volumes. J Chromatogr A 2013; 1299:131-5. [DOI: 10.1016/j.chroma.2013.05.055] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Revised: 05/22/2013] [Accepted: 05/23/2013] [Indexed: 11/17/2022]
|
24
|
Yang H, Ding Y, Cao J, Li P. Twenty-one years of microemulsion electrokinetic chromatography (1991-2012): A powerful analytical tool. Electrophoresis 2013; 34:1273-94. [DOI: 10.1002/elps.201200494] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2012] [Revised: 12/18/2012] [Accepted: 01/22/2013] [Indexed: 12/18/2022]
Affiliation(s)
- Hua Yang
- State Key Laboratory of Natural Medicines (China Pharmaceutical University); Nanjing; P. R. China
| | - Yao Ding
- State Key Laboratory of Natural Medicines (China Pharmaceutical University); Nanjing; P. R. China
| | - Jun Cao
- College of Material Chemistry and Chemical Engineering; Hangzhou Normal University; Hangzhou; P. R. China
| | - Ping Li
- State Key Laboratory of Natural Medicines (China Pharmaceutical University); Nanjing; P. R. China
| |
Collapse
|
25
|
Rabanes HR, Aranas AT, Benbow NL, Quirino JP. Synergistic effect of field enhanced sample injection on micelle to solvent stacking in capillary electrophoresis. J Chromatogr A 2012; 1267:74-9. [DOI: 10.1016/j.chroma.2012.08.073] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2012] [Revised: 08/22/2012] [Accepted: 08/24/2012] [Indexed: 12/28/2022]
|
26
|
Processes involved in sweeping under inhomogeneous electric field conditions as sample enrichment procedure in micellar electrokinetic chromatography. J Chromatogr A 2012; 1264:124-36. [DOI: 10.1016/j.chroma.2012.09.044] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2012] [Revised: 09/13/2012] [Accepted: 09/18/2012] [Indexed: 11/19/2022]
|
27
|
Gao W, Chen Y, Chen G, Xi J, Chen Y, Yang J, Xu N. Trace analysis of three antihistamines in human urine by on-line single drop liquid–liquid–liquid microextraction coupled to sweeping micellar electrokinetic chromatography and its application to pharmacokinetic study. J Chromatogr B Analyt Technol Biomed Life Sci 2012; 904:121-7. [DOI: 10.1016/j.jchromb.2012.07.032] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2012] [Revised: 07/25/2012] [Accepted: 07/27/2012] [Indexed: 01/04/2023]
|
28
|
Quirino JP, Aranas AT. On-line sample concentration via micelle to solvent stacking of cations prepared with aqueous organic solvents in capillary electrophoresis. Electrophoresis 2012; 33:2167-75. [DOI: 10.1002/elps.201200023] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
|
29
|
Quirino JP, Aranas AT. Micelle to solvent stacking of organic cations in micellar electrokinetic chromatography with sodium dodecyl sulfate. J Chromatogr A 2011; 1218:7377-83. [DOI: 10.1016/j.chroma.2011.08.028] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2011] [Revised: 07/30/2011] [Accepted: 08/01/2011] [Indexed: 11/30/2022]
|
30
|
Determination of some sulfonylurea herbicides in soil by a novel liquid-phase microextraction combined with sweeping micellar electrokinetic chromatography. Anal Bioanal Chem 2011; 401:1071-81. [DOI: 10.1007/s00216-011-5138-5] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2011] [Revised: 05/17/2011] [Accepted: 05/23/2011] [Indexed: 10/18/2022]
|
31
|
High-sensitivity capillary electrophoresis method for monitoring purine nucleoside phosphorylase and adenosine deaminase reactions by a reversed electrode polarity switching mode. J Chromatogr A 2011; 1218:4764-71. [PMID: 21664618 DOI: 10.1016/j.chroma.2011.04.085] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2011] [Revised: 04/24/2011] [Accepted: 04/27/2011] [Indexed: 11/22/2022]
Abstract
A simple, efficient, and highly sensitive in-line CE method was developed for the characterization and for inhibition studies of the nucleoside-metabolizing enzymes purine nucleoside phosphorylase (PNP) and adenosine deaminase (ADA) present in membrane preparations of human 1539 melanoma cells. After filling the running buffer (50 mM borate buffer, 100 mM SDS, pH 9.10) into a fused-silica capillary (50 cm effective length × 75 μm), a large sample volume was loaded by hydrodynamic injection (5 psi, 36 s), followed by the removal of the large plug of sample matrix from the capillary using polarity switching (-20 kV). The current was monitored and the polarity was reversed when 95% of the current had been recovered. The separation of the neutral analytes (nucleosides and nucleobases) was performed by applying a voltage of 15 kV. An about 10-fold improvement of sensitivity for the five investigated analytes (adenosine, inosine, adenine, hypoxanthine, xanthine) was achieved by large-volume stacking with polarity switching when compared with CE without stacking. For inosine and adenine detection limits as low as 60 nM were achieved. To the best of our knowledge, this represents the highest sensitivity for nucleoside and nucleobase analysis using CE with UV detection reported so far. The Michaelis-Menten constants (K(m)) for PNP and ADA and the inhibition constants (K(i)) for standard inhibitors determined with the new method were consistent with literature data.
Collapse
|
32
|
Quirino JP. Sweeping of neutral analytes in partial-filling micellar electrokinetic chromatography with electrospray ionization mass spectrometry. Electrophoresis 2011; 32:665-8. [DOI: 10.1002/elps.201000513] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2010] [Revised: 11/15/2010] [Accepted: 11/27/2010] [Indexed: 11/08/2022]
|
33
|
Pérez-Fernández V, García MÁ, Marina ML. Chiral separation of metalaxyl and benalaxyl fungicides by electrokinetic chromatography and determination of enantiomeric impurities. J Chromatogr A 2011; 1218:4877-85. [PMID: 21272886 DOI: 10.1016/j.chroma.2010.12.116] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2010] [Revised: 12/25/2010] [Accepted: 12/31/2010] [Indexed: 11/26/2022]
Abstract
The enantiomers of two acylamine fungicides (metalaxyl and benalaxyl) were separated by EKC using CDs as chiral selectors. The use of 15 mM succinyl-γ-CD for metalaxyl and 5 mM succinyl-β-CD for benalaxyl dissolved in a 50 mM 2-morpholinoethanesulfonic acid buffer (pH 6.5), enabled the chiral separation of metalaxyl enantiomers in 11.5 min with a resolution of 3.1 and the enantiomeric separation of benalaxyl in 7.5 min with a resolution close to 15. Under these conditions, the two enantiomers of each of the chiral compound studied were also separated from folpet, very commonly present in fungicide formulations containing metalaxyl or benalaxyl. The analytical characteristics of the two developed methods were studied in terms of precision, linearity, selectivity, limits of detection (LODs) and limits of quantitation (LOQs) showing their suitability for the determination of these compounds in commercial agrochemical formulations. Finally, the development of an in-capillary preconcentration strategy allowed the detection of enantiomeric impurities up to 1.2% in commercial products labeled as enantiomerically pure in metalaxyl-M.
Collapse
|
34
|
Puangpila C, Petsom A, Nhujak T. Theoretical models of separation selectivity for charged compounds in micellar electrokinetic chromatography. Electrophoresis 2010; 32:203-9. [DOI: 10.1002/elps.201000405] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2010] [Revised: 10/18/2010] [Accepted: 10/18/2010] [Indexed: 11/05/2022]
|
35
|
Liu FK, Chang YC. Using Thiol-Capped Gold Nanoparticles in the Background Solution of MEKC to Concentrate and Separate Neutral Steroids. Chromatographia 2010. [DOI: 10.1365/s10337-010-1785-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
|
36
|
|
37
|
Kumar A, Malik AK, Picó Y. Sample preparation methods for the determination of pesticides in foods using CE-UV/MS. Electrophoresis 2010; 31:2115-25. [DOI: 10.1002/elps.201000021] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
38
|
Somsen GW, Mol R, de Jong GJ. On-line coupling of electrokinetic chromatography and mass spectrometry. J Chromatogr A 2010; 1217:3978-91. [DOI: 10.1016/j.chroma.2010.01.026] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2009] [Revised: 12/23/2009] [Accepted: 01/08/2010] [Indexed: 11/27/2022]
|
39
|
Strategies for the on-line preconcentration and separation of hypolipidaemic drugs using micellar electrokinetic chromatography. J Chromatogr A 2010; 1217:386-93. [DOI: 10.1016/j.chroma.2009.11.043] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2009] [Revised: 11/13/2009] [Accepted: 11/16/2009] [Indexed: 11/22/2022]
|
40
|
Zhang J, Chakraborty U, Foley JP. Determination of residual cell culture media components by MEKC. Electrophoresis 2009; 30:3971-7. [DOI: 10.1002/elps.200900169] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
41
|
Kartsova LA, Bessonova EA. Preconcentration techniques in capillary electrophoresis. JOURNAL OF ANALYTICAL CHEMISTRY 2009. [DOI: 10.1134/s1061934809040029] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
42
|
Different sample stacking strategies for the determination of ertapenem and its impurities by micellar electrokinetic chromatography in pharmaceutical formulation. J Chromatogr A 2009; 1216:2934-42. [DOI: 10.1016/j.chroma.2008.08.025] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2008] [Revised: 07/04/2008] [Accepted: 08/01/2008] [Indexed: 11/21/2022]
|
43
|
Poole CF, Poole SK. Foundations of retention in partition chromatography. J Chromatogr A 2009; 1216:1530-50. [PMID: 19013576 DOI: 10.1016/j.chroma.2008.10.092] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2008] [Revised: 10/22/2008] [Accepted: 10/28/2008] [Indexed: 10/21/2022]
|
44
|
Preconcentration and separation of neutral steroid analytes using a combination of sweeping micellar electrokinetic chromatography and a Au nanoparticle-coated solid phase extraction sorbent. J Chromatogr A 2008; 1215:194-202. [DOI: 10.1016/j.chroma.2008.10.118] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2008] [Revised: 10/27/2008] [Accepted: 10/31/2008] [Indexed: 11/22/2022]
|
45
|
Determination of linezolid and its achiral impurities using sweeping preconcentration by micellar capillary electrophoresis. J Pharm Biomed Anal 2008; 48:321-30. [DOI: 10.1016/j.jpba.2008.01.025] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2007] [Revised: 01/08/2008] [Accepted: 01/14/2008] [Indexed: 11/21/2022]
|
46
|
Lokajová J, Hruška V, Tesařová E, Gaš B. System peaks in micellar electrophoresis: I. Utilization of system peaks for determination of critical micelle concentration. Electrophoresis 2008; 29:1189-95. [DOI: 10.1002/elps.200700780] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
47
|
Poouthree K, Soonthorntantikul W, Leepipatpiboon N, Petsom A, Nhujak T. Comparison of resolution in microemulsion EKC and MEKC employing suppressed electroosmosis: Application to bisphenol-A-diglycidyl ether and its derivatives. Electrophoresis 2007; 28:3705-11. [DOI: 10.1002/elps.200700113] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
48
|
Zhu J, Yu K, Chen X, Hu Z. Comparison of two sample preconcentration strategies for the sensitivity enhancement of flavonoids found in Chinese herbal medicine in micellar electrokinetic chromatography with UV detection. J Chromatogr A 2007; 1166:191-200. [PMID: 17723234 DOI: 10.1016/j.chroma.2007.08.018] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2007] [Revised: 08/02/2007] [Accepted: 08/09/2007] [Indexed: 11/17/2022]
Abstract
Two on-column preconcentration techniques named stacking with reverse migrating micelles (SRMM) and anion selective electrokinetic injection and a water plug-sweeping with reverse migrating micelles (ASIW-sweep-RMM) were used and compared for concentration and separation of flavonoids in Chinese herbs using reverse migration micellar electrokinetic chromatography (RM-MEKC). The optimal background electrolyte (BGE) used for separation and preconcentration was a solution composed of 20mM phosphoric acid (H(3)PO(4))-100mM sodium dodecyl sulfate (SDS)-20% (v/v) acetonitrile (ACN) buffer (pH 2.0), the applied voltage was -15kV. To achieve reasonable results of the two techniques, the conditions which affected preconcentration were examined. A comparison of used techniques with normal hydrodynamic injection (5s), concerning enhancement factors and limits of detection (LODs) was presented. Under the optimum stacking conditions, about 27-37- and 45-194-fold improvement in the detection sensitivity was obtained for SRMM and ASIW-sweep-RMM, respectively, compared to usual hydrodynamic sample injection (5s). The LODs (S/N=3) for SRMM and ASIW-sweep-RMM in terms of peak height, can reach down to 1.15 x 10(-2) microg/ml for hesperetin and 2.4 x 10(-3) microg/ml for nobiletin, respectively. Finally, the amounts of the six flavonoids in extract of Fructus aurantii Immaturus were successfully determined using ASIW-sweep-RMM. The six analytes were baseline separated with sample matrix under the optimum ASIW-sweep-RMM conditions and the experimental results showed that preconcentration was well achieved after the dilution of sample solutions.
Collapse
Affiliation(s)
- Jinhua Zhu
- State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000, China
| | | | | | | |
Collapse
|
49
|
Spégel P, Viberg P, Carlstedt J, Petersson P, Jörntén-Karlsson M. Continuous full filling capillary electrochromatography: Nanoparticle synthesis and evaluation. J Chromatogr A 2007; 1154:379-85. [PMID: 17449050 DOI: 10.1016/j.chroma.2007.02.092] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2006] [Revised: 02/13/2007] [Accepted: 02/20/2007] [Indexed: 10/23/2022]
Abstract
Reversed phase continuous full filling capillary electrochromatography with electrospray ionisation mass spectrometric detection was performed with highly sulphated poly[styrene-co-(lauryl methacrylate)-co-(divinylbenzene)] nanoparticles. The nanoparticles that contained a hydrophobic core and a hydrophilic surface were prepared in a one step synthesis using soap free emulsion polymerisation. By changing the concentration of monomers, the polymerisation temperature, and the polarity of the dispersive phase, the size of the nanoparticles could be controlled. With the optimised conditions, nanoparticles with an average size of 157 nm were obtained. These nanoparticles were dispersed in the background electrolyte and used for reversed phase continuous full filling. An orthogonal electrospray ionisation interface was used to separate the eluting nanoparticles from the eluting analytes prior to mass spectrometry detection. Compared to previous studies on reversed phase continuous full filling, the retention, the separation efficiency, and the resolution of a homologous series of dialkyl phthalates were greatly improved.
Collapse
Affiliation(s)
- Peter Spégel
- Analytical Chemistry, Centre for Chemistry and Chemical Engineering, Lund University, P.O. Box 124, SE-221 00 Lund, Sweden
| | | | | | | | | |
Collapse
|
50
|
Poouthree K, Leepipatpiboon N, Petsom A, Nhujak T. Retention factor and retention index of homologous series compounds in microemulsion electrokinetic chromatography employing suppressed electroosmosis. Electrophoresis 2007; 28:767-78. [PMID: 17265537 DOI: 10.1002/elps.200600275] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The retention factor (k) and retention index (I) of homologous series compounds such as alkylbenzenes (BZ), alkylaryl ketones, alkylbenzoates, and alkylparabens in microemulsion electrokinetic chromatography (MEEKC) with suppressed electroosmosis were investigated in a wide range of SDS concentrations ([SDS]), temperatures, and concentrations of organic cosolvents (phi). Using BZ as standards, the retention indices of other homologous series compounds were determined and they were found to be independent of [SDS] and temperature, while are dependent on the types and concentrations of organic cosolvents. The retention factor linearly increases with increasing [SDS], while linearly decreases with increasing temperature. The value of log k linearly decreases with increasing phi for methanol, ethanol, or ACN, while decreases by a second-degree polynomial with increasing phi for 2-propanol. Excellent agreement was found between the observed and predicted values of log k of analytes in MEEKC at given [SDS] and phi, where the predicted values were obtained from modified equations of the linear relationship of log k as functions of [SDS], the number of carbons, and phi. Therefore, both k and I can be used for peak identification of homologous series compounds.
Collapse
Affiliation(s)
- Kieatsuda Poouthree
- Chromatography and Separation Research Group, Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok, Thailand
| | | | | | | |
Collapse
|