1
|
Laglera LM, Uskaikar H, Klaas C, Naqvi SWA, Wolf-Gladrow DA, Tovar-Sánchez A. Dissolved and particulate iron redox speciation during the LOHAFEX fertilization experiment. MARINE POLLUTION BULLETIN 2022; 184:114161. [PMID: 36179387 DOI: 10.1016/j.marpolbul.2022.114161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 09/15/2022] [Accepted: 09/17/2022] [Indexed: 06/16/2023]
Abstract
The redox speciation of iron was determined during the iron fertilization LOHAFEX and for the first time, the chemiluminescence assay of filtered and unfiltered samples was systematically compared. We hypothesize that higher chemiluminescence in unfiltered samples was caused by Fe(II) adsorbed onto biological particles. Dissolved and particulate Fe(II) increased in the mixed layer steadily 6-fold during the first two weeks and decreased back to initial levels by the end of LOHAFEX. Both Fe(II) forms did not show diel cycles downplaying the role of photoreduction. The chemiluminescence of unfiltered samples across the patch boundaries showed strong gradients, correlated significantly to biomass and the photosynthetic efficiency and were higher at night, indicative of a biological control. At 150 m deep, a secondary maximum of dissolved Fe(II) was associated with maxima of nitrite and ammonium despite high oxygen concentrations. We hypothesize that during LOHAFEX, iron redox speciation was mostly regulated by trophic interactions.
Collapse
Affiliation(s)
- Luis M Laglera
- FI-TRACE, Departamento de Química, Universidad de las Islas Baleares, Palma, Balearic Islands 07122, Spain; Laboratori Interdisciplinari sobre Canvi Climàtic, Universidad de las Islas Baleares, Palma, Balearic Islands 07122, Spain.
| | - Hema Uskaikar
- National Institute of Oceanography, Dona Paula, Goa, India
| | - Christine Klaas
- Alfred Wegener Institute for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany
| | | | - Dieter A Wolf-Gladrow
- Alfred Wegener Institute for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany
| | - Antonio Tovar-Sánchez
- Department of Ecology and Coastal Management, Andalusian Institute for Marine Science, ICMAN (CSIC), Campus Universitario Río San Pedro, Puerto Real, Cádiz, Spain
| |
Collapse
|
2
|
Cooray AT, Pullin MJ. Ferrozine colorimetry and reverse flow injection analysis (rFIA) based method for the determination of total iron in aqueous solutions at nanomolar concentrations. J INDIAN CHEM SOC 2022. [DOI: 10.1016/j.jics.2022.100541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
3
|
Zhang S, Shi Y, Deng J, Zhang J, Cheng M, Yu G. A High Selective Chemiluminescent Probe Derived from
Iso
‐luminol Enabling High Sensitive Determination of Ferrous Ions in the Environmental Waters. CHINESE J CHEM 2021. [DOI: 10.1002/cjoc.202100057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Shenghai Zhang
- Quality Supervision and Inspection Centre of Se‐enriched Food of Shaanxi Province School of Chemistry & Chemical Engineering Ankang Univerisity, An'kang Shaanxi 725000 China
- Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, School of Chemistry and Chemical Engineering Shaanxi Normal University Xi'an Shaanxi 710119 China
| | - Yalin Shi
- Quality Supervision and Inspection Centre of Se‐enriched Food of Shaanxi Province School of Chemistry & Chemical Engineering Ankang Univerisity, An'kang Shaanxi 725000 China
| | - Jiawang Deng
- Quality Supervision and Inspection Centre of Se‐enriched Food of Shaanxi Province School of Chemistry & Chemical Engineering Ankang Univerisity, An'kang Shaanxi 725000 China
| | - Jidong Zhang
- Quality Supervision and Inspection Centre of Se‐enriched Food of Shaanxi Province School of Chemistry & Chemical Engineering Ankang Univerisity, An'kang Shaanxi 725000 China
| | - Mengqi Cheng
- Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, School of Chemistry and Chemical Engineering Shaanxi Normal University Xi'an Shaanxi 710119 China
| | - Geting Yu
- Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, School of Chemistry and Chemical Engineering Shaanxi Normal University Xi'an Shaanxi 710119 China
| |
Collapse
|
4
|
Spectrophotometric flow injection determination of dissolved titanium in seawater exploiting in-line nitrilotriacetic acid resin preconcentration and a long path length liquid waveguide capillary cell. Anal Chim Acta 2019; 1053:54-61. [PMID: 30712569 DOI: 10.1016/j.aca.2018.11.034] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2018] [Revised: 11/14/2018] [Accepted: 11/15/2018] [Indexed: 11/23/2022]
Abstract
A sensitive spectrophotometric method for the determination of dissolved titanium (Ti) in seawater is developed. It involves in-line preconcentration and a long path length liquid waveguide capillary cell (LWCC). Nitrilotriacetic acid (NTA) resin is used to preconcentrate Ti from ∼25 mL seawater sample at pH 1.7, and elution is accomplished with 0.8 mol L-1 hydrochloride acid. The eluted Ti solution is buffered to pH 6.0 with 1.0 mol L-1 ammonium acetate and mixed with 1.5 mmol L-1 Tiron solution. The mixture is then injected into LWCC and measured by spectrophotometry at 420 nm. Before the preconcentration step, the sample is treated with 7 mmol L-1 ascorbic acid to reduce Fe(III) to Fe(II), in order to eliminate the Fe interference. The method is not interfered by Fe(III) and Cu(II) present in seawater samples at concentrations 50-fold higher in relation to Ti, and by Cd(II), Pb(II), Cr(VI), Mn(II), Al(III), Zn(II), and Ni(II) at concentrations 100-fold higher in relation to Ti. It is time efficient (7.5 minutes per sample), sensitive (0.10 nmol L-1 detection limit), precise (1.40% measurement RSD at 1.00 nmol L-1 Ti) and is characterized by a linear range of 0.50-5.00 nmol L-1 Ti. The method was applied to analysis of natural water samples collected from the Jiulongjiang Estuary, Fujian, China.
Collapse
|
5
|
Li N, Than A, Sun C, Tian J, Chen J, Pu K, Dong X, Chen P. Monitoring Dynamic Cellular Redox Homeostasis Using Fluorescence-Switchable Graphene Quantum Dots. ACS NANO 2016; 10:11475-11482. [PMID: 28024361 DOI: 10.1021/acsnano.6b07237] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Monitoring cellular redox homeostasis is critical to the understanding of many physiological functions ranging from immune reactions to metabolism, as well as to the understanding of pathological development ranging from tumorigenesis to aging. Nevertheless, there is currently a lack of appropriate probes for this ambition, which should be reversibly, sensitively, and promptly responsive to a wide range of physiological oxidants and reductants. In this work, a redox-sensitive fluorescence-switchable probe is designed based on graphene quantum dots (GQDs) functionalized with a chelated redox Fe2+/Fe3+ couple. The underlying mechanism is investigated and discussed. The high sensitivity and fast response are attributable to the fact that the GQD's photoluminescence is highly sensitive to photon-induced electron transfer because of its ultrasmall size and associated prominent quantum confinement effect. Also taking advantages of GQDs' excellent photostability, biocompatibility, and readiness for cell uptake, our reversibly tunable fluorescence probe is employed to monitor in real time the triggered dynamic change of the intracellular redox state. This addition to the limited arsenal of available redox probes shall be useful to the still poorly understood redox biology, as well as for monitoring environment or chemical processes involving redox reactions.
Collapse
Affiliation(s)
- Nan Li
- Division of Bioengineering, School of Chemical & Biomedical Engineering, Nanyang Technological University , 70 Nanyang Drive, Singapore 637457
| | - Aung Than
- Division of Bioengineering, School of Chemical & Biomedical Engineering, Nanyang Technological University , 70 Nanyang Drive, Singapore 637457
| | - Chencheng Sun
- Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University (NanjingTech) , 30 South Puzhu Road, Nanjing 211816, China
| | - Jingqi Tian
- Division of Bioengineering, School of Chemical & Biomedical Engineering, Nanyang Technological University , 70 Nanyang Drive, Singapore 637457
| | - Jie Chen
- Division of Bioengineering, School of Chemical & Biomedical Engineering, Nanyang Technological University , 70 Nanyang Drive, Singapore 637457
| | - Kanyi Pu
- Division of Bioengineering, School of Chemical & Biomedical Engineering, Nanyang Technological University , 70 Nanyang Drive, Singapore 637457
| | - Xiaochen Dong
- Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University (NanjingTech) , 30 South Puzhu Road, Nanjing 211816, China
| | - Peng Chen
- Division of Bioengineering, School of Chemical & Biomedical Engineering, Nanyang Technological University , 70 Nanyang Drive, Singapore 637457
| |
Collapse
|
6
|
Saqib M, Li S, Gao W, Majeed S, Qi L, Liu Z, Xu G. N-Hydroxysuccinimide as an effective chemiluminescence coreactant for highly selective and sensitive detection. Anal Bioanal Chem 2016; 408:8851-8857. [DOI: 10.1007/s00216-016-9930-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2016] [Revised: 08/09/2016] [Accepted: 09/07/2016] [Indexed: 02/06/2023]
|
7
|
Floor GH, Clough R, Lohan MC, Ussher SJ, Worsfold PJ, Quétel CR. Combined uncertainty estimation for the determination of the dissolved iron amount content in seawater using flow injection with chemiluminescence detection. LIMNOLOGY AND OCEANOGRAPHY, METHODS 2015; 13:673-686. [PMID: 27610049 PMCID: PMC4995610 DOI: 10.1002/lom3.10057] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2014] [Revised: 06/25/2015] [Accepted: 07/21/2015] [Indexed: 05/15/2023]
Abstract
This work assesses the components contributing to the combined uncertainty budget associated with the measurement of the Fe amount content by flow injection chemiluminescence (FI-CL) in <0.2 μm filtered and acidified seawater samples. Amounts of loaded standard solutions and samples were determined gravimetrically by differential weighing. Up to 5% variations in the loaded masses were observed during measurements, in contradiction to the usual assumptions made when operating under constant loading time conditions. Hence signal intensities (V) were normalised to the loaded mass and plots of average normalised intensities (in V kg-1) vs. values of the Fe amount content (in nmol kg-1) added to a "low level" iron seawater matrix were used to produce the calibration graphs. The measurement procedure implemented and the uncertainty estimation process developed were validated from the agreement obtained with consensus values for three SAFe and GEOTRACES reference materials (D2, GS, and GD). Relative expanded uncertainties for peak height and peak area based results were estimated to be around 12% and 10% (coverage factor k = 2), respectively. The most important contributory factors were the uncertainty on the sensitivity coefficient (i.e., calibration slope) and the within-sequence-stability (i.e., the signal stability over several hours of operation; here 32 h). For GD, using peak height measurements, these factors contributed respectively 69.7% and 21.6% while the short-term repeatability accounted for only 7.9%. Therefore, an uncertainty estimation based on the intensity repeatability alone, as is often done in FI-CL studies, is not a realistic estimation of the overall uncertainty of the procedure.
Collapse
Affiliation(s)
- Geerke H Floor
- Institute for Reference Materials and Measurements, Joint Research Centre-European Commission Geel Belgium; Present address: GFZ German Research Centre for Geosciences, Helmholtz Centre Potsdam Potsdam Germany
| | - Robert Clough
- Biogeochemistry Research Centre, School of Geography, Earth and Environmental Sciences Plymouth University Plymouth United Kingdom
| | - Maeve C Lohan
- Biogeochemistry Research Centre, School of Geography, Earth and Environmental Sciences Plymouth University Plymouth United Kingdom
| | - Simon J Ussher
- Biogeochemistry Research Centre, School of Geography, Earth and Environmental Sciences Plymouth University Plymouth United Kingdom
| | - Paul J Worsfold
- Biogeochemistry Research Centre, School of Geography, Earth and Environmental Sciences Plymouth University Plymouth United Kingdom
| | - Christophe R Quétel
- Institute for Reference Materials and Measurements, Joint Research Centre-European Commission Geel Belgium
| |
Collapse
|
8
|
Gao W, Qi W, Lai J, Qi L, Majeed S, Xu G. Thiourea dioxide as a unique eco-friendly coreactant for luminol chemiluminescence in the sensitive detection of luminol, thiourea dioxide and cobalt ions. Chem Commun (Camb) 2015; 51:1620-3. [DOI: 10.1039/c4cc08904a] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Thiourea dioxide, a unique reductant that can generate oxygen upon decomposition, has been investigated as an efficient, cost-effective, and stable coreactant.
Collapse
Affiliation(s)
- Wenyue Gao
- State Key Laboratory of Electroanalytical Chemistry
- Changchun Institute of Applied Chemistry
- Chinese Academy of Sciences
- Changchun
- China
| | - Wenjing Qi
- State Key Laboratory of Electroanalytical Chemistry
- Changchun Institute of Applied Chemistry
- Chinese Academy of Sciences
- Changchun
- China
| | - Jianping Lai
- State Key Laboratory of Electroanalytical Chemistry
- Changchun Institute of Applied Chemistry
- Chinese Academy of Sciences
- Changchun
- China
| | - Liming Qi
- State Key Laboratory of Electroanalytical Chemistry
- Changchun Institute of Applied Chemistry
- Chinese Academy of Sciences
- Changchun
- China
| | - Saadat Majeed
- State Key Laboratory of Electroanalytical Chemistry
- Changchun Institute of Applied Chemistry
- Chinese Academy of Sciences
- Changchun
- China
| | - Guobao Xu
- State Key Laboratory of Electroanalytical Chemistry
- Changchun Institute of Applied Chemistry
- Chinese Academy of Sciences
- Changchun
- China
| |
Collapse
|
9
|
Saqib M, Gao W, Lai J, Qi L, Majeed S, Gilani MRHS, Xu G. Hydroxylamine-O-sulfonic acid as an efficient coreactant for luminol chemiluminescence for selective and sensitive detection. Chem Commun (Camb) 2015; 51:6536-9. [DOI: 10.1039/c5cc01090j] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
HOSA, a versatile synthetic reagent, has been explored as an effective chemiluminescence coreactant for the sensitive detection of luminol, HOSA, and Co2+, including selective Co2+ detection.
Collapse
Affiliation(s)
- Muhammad Saqib
- State Key Laboratory of Electroanalytical Chemistry
- Changchun Institute of Applied Chemistry
- Chinese Academy of Sciences
- Changchun
- China
| | - Wenyue Gao
- State Key Laboratory of Electroanalytical Chemistry
- Changchun Institute of Applied Chemistry
- Chinese Academy of Sciences
- Changchun
- China
| | - Jianping Lai
- State Key Laboratory of Electroanalytical Chemistry
- Changchun Institute of Applied Chemistry
- Chinese Academy of Sciences
- Changchun
- China
| | - Liming Qi
- State Key Laboratory of Electroanalytical Chemistry
- Changchun Institute of Applied Chemistry
- Chinese Academy of Sciences
- Changchun
- China
| | - Saadat Majeed
- State Key Laboratory of Electroanalytical Chemistry
- Changchun Institute of Applied Chemistry
- Chinese Academy of Sciences
- Changchun
- China
| | - Muhammad Rehan Hasan Shah Gilani
- State Key Laboratory of Electroanalytical Chemistry
- Changchun Institute of Applied Chemistry
- Chinese Academy of Sciences
- Changchun
- China
| | - Guobao Xu
- State Key Laboratory of Electroanalytical Chemistry
- Changchun Institute of Applied Chemistry
- Chinese Academy of Sciences
- Changchun
- China
| |
Collapse
|
10
|
Determination of melamine by flow injection analysis based on chemiluminescence system. Food Chem 2011; 127:842-6. [PMID: 23140744 DOI: 10.1016/j.foodchem.2011.01.021] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2010] [Revised: 12/09/2010] [Accepted: 01/01/2011] [Indexed: 11/22/2022]
Abstract
In this paper, based upon the phenomenon that melamine can obviously enhance the CL signal of the luminol-H(2)O(2) system in basic medium, a simple, rapid and sensitive flow injection chemiluminescence (FI-CL) method for the determination of melamine has been developed. Under the optimum conditions, the linear range for the determination of melamine was 0.2-80μgmL(-1) with a detection limit of 0.12μgmL(-1) calculated as proposed by IUPAC and a relative standard deviation of 3.26% for 11 solutions of 10μgmL(-1) melamine on the same day. The proposed method was satisfactorily applied to determine melamine in milk-based products and satisfactory results were obtained without interferences from the sample matrix. Moreover, one assay produce takes only 25s and the minimum sampling rate is about 120 samplesh(-1), which indicated that the FI-CL method was suitable for high throughput and real-time melamine analysis.
Collapse
|
11
|
Christodouleas D, Fotakis C, Economou A, Papadopoulos K, Timotheou-Potamia M, Calokerinos A. Flow-Based Methods with Chemiluminescence Detection for Food and Environmental Analysis: A Review. ANAL LETT 2011. [DOI: 10.1080/00032719.2010.500791] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
12
|
Sheng Z, Han H, Yang G. A novel method for sensing of methimazole using gold nanoparticle-catalyzed chemiluminescent reaction. LUMINESCENCE 2010; 26:196-201. [DOI: 10.1002/bio.1207] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2009] [Revised: 12/25/2009] [Accepted: 01/21/2010] [Indexed: 11/06/2022]
|
13
|
Borman CJ, Sullivan BP, Eggleston CM, Colberg PJS. The use of flow-injection analysis with chemiluminescence detection of aqueous ferrous iron in waters containing high concentrations of organic compounds. SENSORS (BASEL, SWITZERLAND) 2009; 9:4390-406. [PMID: 22408532 PMCID: PMC3291917 DOI: 10.3390/s90604390] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2009] [Revised: 06/01/2009] [Accepted: 06/03/2009] [Indexed: 11/16/2022]
Abstract
An evaluation of flow-injection analysis with chemiluminescence detection (FIA-CL) to quantify Fe(2+) ((aq)) in freshwaters was performed. Iron-coordinating and/or iron-reducing compounds, dissolved organic matter (DOM), and samples from two natural water systems were used to amend standard solutions of Fe(2+) ((aq)). Slopes of the response curves from ferrous iron standards (1 - 100 nM) were compared to the response curves of iron standards containing the amendments. Results suggest that FIA-CL is not suitable for systems containing ascorbate, hydroxylamine, cysteine or DOM. Little or no change in sensitivity occurred in solutions of oxalate and glycine or in natural waters with little organic matter.
Collapse
Affiliation(s)
- Christopher J. Borman
- Department of Chemistry, University of Wyoming, Dept 3838, 1000 E. University Avenue, Laramie, Wyoming 82071, USA
| | - B. Patrick Sullivan
- Department of Chemistry, University of Wyoming, Dept 3838, 1000 E. University Avenue, Laramie, Wyoming 82071, USA
| | - Carrick M. Eggleston
- Department of Geology and Geophysics, University of Wyoming, Dept 3006, 1000 E. University Avenue, Laramie, Wyoming 82071, USA; E-Mail: (C.M.E.)
| | - Patricia J. S. Colberg
- Department of Civil and Architectural Engineering, University of Wyoming, Dept 3295, 1000 E. University Avenue, Laramie, Wyoming 82071, USA; E-Mail: (P.J.S.C.)
| |
Collapse
|
14
|
Liu YM, Liu ZL, Shi YM, Tian W. The determination of glutamine with flow-injection chemiluminescence detection and mechanism study. LUMINESCENCE 2009; 25:50-4. [DOI: 10.1002/bio.1143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
15
|
Li B, Deng Q, Guo L, Zhang Z. Secondary chemiluminescence emission of the luminol-ferricyanide system induced by reducing agents. Mikrochim Acta 2007. [DOI: 10.1007/s00604-007-0859-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
16
|
Liu W, Zhang Z, Liu Z. Determination of β-lactam antibiotics in milk using micro-flow chemiluminescence system with on-line solid phase extraction. Anal Chim Acta 2007; 592:187-92. [PMID: 17512825 DOI: 10.1016/j.aca.2007.04.027] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2007] [Revised: 04/08/2007] [Accepted: 04/16/2007] [Indexed: 11/30/2022]
Abstract
In this paper, a chemiluminescence (CL) micro-flow system combined with on-line solid phase extraction (SPE) is presented for determination of beta-lactam antibiotics (penicillin, cefradine, cefadroxil, cefalexin) in milk. It is based on the enhancement effect of beta-lactam antibiotics on the luminol-K3Fe(CN)6 CL system. The micro-flow system was fabricated from two polymethyl methacrylate (PMMA) plates (50 mm x 40 mm x 5 mm) with the microchannels of 200 microm wide and 150 microm deep. C18-modified silica gel was packed into the microchannel (length: 10 mm; width: 1 mm; depth: 500 microm) to serve as SPE device. Extraction and preconcentration of the analytes were carried out using on-line SPE micro-flow system and the selectivity of CL detection was improved. The detection limits were 0.5 microg mL(-1) of penicillin, 0.04 microg mL(-1) of cefradine, 0.08 microg mL(-1) of cefadroxil and 0.1 microg mL(-1) of cefalexin. The proposed method was also applied to analyze the beta-lactam antibiotics in milk. Experimental results were in good agreement with those obtained by high performance liquid chromatography (HPLC) method with UV detection.
Collapse
Affiliation(s)
- Wei Liu
- Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, School of Chemistry and Materials Science, Shaanxi Normal University, Xi'an 710062, PR China
| | | | | |
Collapse
|
17
|
Laglera LM, van den Berg CMG. Wavelength dependence of the photochemical reduction of iron in arctic seawater. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2007; 41:2296-302. [PMID: 17438778 DOI: 10.1021/es061994h] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Chemiluminescence measurements of the photochemical reduction of iron in cold, high-latitude waters (79 degrees N) show that a significant fraction (20%) of the dissolved iron is reduced when exposed to sunlight. The reduction is immediately initiated and the transition to a steady-state concentration of approximately 200 pM photochemical Fe(II) is achieved within approximately 40 s. The photochemical Fe(ll) is reoxidized to Fe(III) in less than a minute upon blocking the sunlight, much faster than expected, which is ascribed to reaction with photochemically produced oxidants. Using filters to block different ranges of the incident sunlight it was found that 35% of the photochemical Fe(II) was produced in the UV-B range (300-315 nm), 30% in the range 315-360 nm, and 30% at higher wavelengths. Measurements of light attenuation as a function of depth indicate that photochemical Fe(II) at a depth of 5 m in high-latitude waters should amount to approximately10% of that at the surface. The fast kinetics modulate the paramount importance that photochemical reactions may have on the bioavailability of iron in surface waters.
Collapse
Affiliation(s)
- Luis M Laglera
- Department of Earth and Ocean Sciences, University of Liverpool, Liverpool, L69 3GP, UK
| | | |
Collapse
|
18
|
Vong L, Laës A, Blain S. Determination of iron-porphyrin-like complexes at nanomolar levels in seawater. Anal Chim Acta 2007; 588:237-44. [PMID: 17386816 DOI: 10.1016/j.aca.2007.02.007] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2006] [Revised: 02/02/2007] [Accepted: 02/02/2007] [Indexed: 11/30/2022]
Abstract
A new method for the non-specific determination of iron-porphyrin-like complexes in natural waters has been developed. It is based on the chemiluminescent oxidation of the luminol in the presence of dioxygen (O2) at pH 13. The method has been implemented in a FIA manifold that allowed the direct injection of seawater. The limit of detection is 0.11 nM of equivalent hemin (Fe-protoporphyrin IX). Fe2+, Fe3+, H2O2, siderophore (deferoxamin mesylate), humic acid and phytic acid did not interfere when they were present at the concentrations expected in seawater. Metal free porphyrin and Mg, Cu, Co porphyrin complexes did not induce a significant chemiluminescent signal. Poisoned unfiltered samples could be stored for several weeks before analyses. The new method was successfully applied to the determination of the Fe-porphyrin complexes contained in cultured phytoplankton and in natural samples.
Collapse
Affiliation(s)
- Lilita Vong
- Laboratoire d'Océanographie et de Biogéochimie, Université de la Méditerranée, Centre d'Oceanology de Marseille, Unité Mixte de Recherche CNRS 6535, Campus de Luminy, Case 901, 163, Avenue de Luminy, F-13288 Marseille Cedex 09, France
| | | | | |
Collapse
|
19
|
Marquette CA, Blum LJ. Applications of the luminol chemiluminescent reaction in analytical chemistry. Anal Bioanal Chem 2006; 385:546-54. [PMID: 16715276 DOI: 10.1007/s00216-006-0439-9] [Citation(s) in RCA: 155] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2005] [Revised: 03/17/2006] [Accepted: 03/17/2006] [Indexed: 10/24/2022]
Abstract
This critical review discusses the results published between 2000 and 2005 on the development of analytical systems based on the luminol chemiluminescent and electrochemiluminescent reactions. An increasing number of non-specific detection systems based on the enhancing, inhibiting or catalysing effect of a large range of compounds have been published. Possible detected compounds and their concomitant presence in samples are discussed. Chemiluminescent and electrochemiluminescent reactions were also found to merge in biochip and microarray development as a possible substitute to the well-established but hardly quantitative fluorescent detections.
Collapse
Affiliation(s)
- Christophe A Marquette
- Laboratoire de Génie Enzymatique et Biomoléculaire, UMR 5013 EMB2, CNRS -Université Claude Bernard Lyon 1, Bât CPE, 43, bd du 11 Novembre 1918, 69622 Villeurbanne, Cedex, France.
| | | |
Collapse
|
20
|
Waseem A, Yaqoob M, Nabi A. Determination of thyroxine in pharmaceuticals using flow injection with luminol chemiluminescence inhibition detection. LUMINESCENCE 2006; 21:174-8. [PMID: 16645953 DOI: 10.1002/bio.902] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
A simple flow injection method is reported for the determination of thyroxine, based on its inhibition effect on luminol-iron(II) chemiluminescence in alkaline medium in the presence of molecular oxygen. The detection limits (2s) for d- and l-thyroxine are 0.08 and 0.1 mg/L, respectively, with a sample throughput of 100/h. The calibration data for d- and l-thyroxine over the range 0.2-1.0 mg/L gives correlation coefficients (r(2)) of 0.9915 and 0.984 with relative standard deviations (RSD; n = 4) in the range 1.2-2.8%. The effects of some organic compounds was studied on luminol-iron(II) CL system for thyroxine determination. The method was applied to pharmaceutical thyroxine tablets and the results obtained (in the range 50.5 +/- 2.0-51.6 +/- 1.2 microg l-thyroxine/tablet) were in reasonable agreement with the value quoted.
Collapse
Affiliation(s)
- Amir Waseem
- Department of Chemistry, University of Balochistan, Quetta, Pakistan.
| | | | | |
Collapse
|