University of North Florida
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Stuart Chalk, Ph.D.
Department of Chemistry
University of North Florida
Phone: 1-904-620-1938
Fax: 1-904-620-3535
Website: @unf

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Classification: Marine

Citations 5

"Speciation Of Arsenobetaine In Marine Organisms Using A Selective Leaching/digestion Procedure And Hydride Generation Atomic Absorption Spectrometry"
Anal. Chim. Acta 1997 Volume 337, Issue 3 Pages 323-327
M. Ochsenkühn-Petropulu*, J. Varsamis and G. Parissakis

Abstract: An analytical process has been developed based on the selective leaching of arsenobetaine from marine organisms with methanol/chloroform (2:1) and on a subsequent pressurized digestion of the methanol phase with a suitable acid combination (H2SO4/HNO3), followed by hydride generation atomic absorption spectrometry for the arsenic determination. The method has been successfully applied to the speciation of arsenobetaine and the digestion procedure allows the determination of total arsenic in the reference materials, CRM-278, a mussel tissue and TORT-1, a lobster's hepatopancreas, proving its reliability. Besides, the technique developed was then applied to real marine organisms, such as the blue mussels and the marine snails, Murex trunculus, a biomarker for marine pollution studies, all collected from an industrial region near Athens, the Elevsis Bay. The main species found in all investigated marine organisms was arsenobetaine, corresponding to 87-100% of total arsenic.
Arsenoβine Sample preparation Spectrophotometry Volatile generation Speciation Volatile generation

"Semi-automatic Determination Of Tin In Marine Materials By Continuous-flow Hydride-generation Inductively Coupled Plasma Atomic-emission Spectrometry"
Fresenius J. Anal. Chem. 1997 Volume 357, Issue 7 Pages 822-826
Yong-Lai Feng, H. Narasaki, Hong-Yuan Chen, Li-Ching Tian

Abstract: Sample (1.25 g) was equilibrated overnight with 15 mL 68% HNO3 and 2 mL 70% HClO4, then digested by heating with 0.5 mL concentrated H2SO4. The resulting solution was adjusted to pH 3.5 with 4 M NaOH and passed through a DIAION SA 10A anion-exchange resin column (15 cm x 8 mm i.d.; Mitsubishi Kasei Corp., Tokyo, Japan). The eluate was mixed with 3.5 mL 3 M H2SO4 and 2.5 mL 10% L-cysteine hydrochloride monohydrate, diluted to 25 mL and then analyzed for Sn by continuous-flow hydride-generation ICP-AES at 189.93 nm (operating conditions given). The detection limit was 0.4 ng/mL Sn and the RSD (n = 10) was 0.5%. The effects of varying the H2SO4, NaBH4 (hydride-generating reagent) and NaOH concentrations, Ar (carrier gas) and NaBH4 flow rates and the ratio of flow rates of sample solution and NaBH4 were investigated (results presented). The effects of interferents were also investigated, along with seven methods for masking interference (results tabulated). The method was applied to an environmental (marine) CRM. The result agreed with the certified value and the RSD (n = 6) was 0.95%.
Tin Ion exchange Sample preparation Spectrophotometry Column Detection limit Interferences Reference material

"Determination Of Inorganic Arsenic And Its Organic Metabolites In Urine By Flow Injection Hydride Generation Atomic Absorption Spectrometry"
Clin. Chem. 1993 Volume 39, Issue 8 Pages 1662-1667
CP Hanna, JF Tyson and S McIntosh

Abstract: Urine was applied to a 1 mL Bond-Elut cartridge with HNO3/ethanol (1:10). The eluate was heated to ~120°C with solid K2Cr2O7 and concentrated HNO3 until the volume was reduced to ~1 mL and then concentrated H2SO4 was added. After heating to ~250°C for 90 min, the mixture was cooled for 1 min before H2O2 was added and the mixture reheated. After cooling, the mixture was treated with KI in HCl before flow injection AAS with mixing with HCl and sodium borohydride in NaOH solution Recovery was 108, 112, 104 and 95% for As(III), As(V), monomethylarsenic and dimethylarsenic, respectively. The detection limits were 0.1-0.2 µg/l and the RSD were 2.3-3.5%. A method has been developed for the determination of inorganic arsenic [As(III) and As(V)] and its organic metabolites (monomethylarsenic and dimethylarsenic) in urine by flow injection hydride generation atomic absorption spectrometry. The nontoxic seafood-derived arsenobetaine and arsenocholine species were first separated by a solid-phase extraction procedure. The remaining sample was digested with a mixture of nitric and sulfuric acids and potassium dichromate, followed by attack with hydrogen peroxide. The resulting As(V) was reduced to As(III) with potassium iodide in hydrochloric acid before injection into the flow injection manifold. The percentage analytical recoveries (mean±95% confidence interval) of various arsenic species added to a urine specimen at 250 µg/L were 108±2, 112±11, 104±7, and 95±5 for As(III), As(V), monomethylarsenic, and dimethylarsenic, respectively. For the determination of arsenic in Standard Reference Material 2670 (toxic metals in human urine), results agreed with the certified value (480±100 µg/L). Analyses of samples for the Centre de Toxicologie du Quebec, containing seafood-derived species, demonstrated the viability of the separation procedure. Detection limits were between 0.1 and 0.2µg/L in the solution injected into the manifold, and precision at 10 µg/L was between 2% and 3% (CV). These preliminary results show that the method might be applicable to determinations of arsenic in a range of clinical urine specimens.
Arsenic, inorganic Arsenic(3+) Arsenic(5+) Monomethylarsine Dimethylarsenic Spectrophotometry Clinical analysis Volatile generation Reference material Speciation Volatile generation

"Cytosolic Metal Speciation Studies By Sequential, Online, SE-IE/HPLC-ICP-MS"
Mar. Environ. Res. 1998 Volume 46, Issue 1-5 Pages 573-577
A. Z. Mason and R. F. Meraz

Abstract: A procedure involving directly coupled HPLC-ICP-MS is described for the quantification of metals associated with cytosolic proteins. Selectivity is achieved by sequential fractionation by size exclusion (TSK SW2000) followed by ion exchange chromatography (Showdex DEAE). Spectra on up to 11 masses for six elements were acquired simultaneously by scanning the quadrapole in the peak hopping mode. A flow injection loop inserted downstream of the columns was used to monitor analyte recovery and quantify the ion intensity profiles from the MS. Reproducibility of analysis was approximately 2-5% and absolute detection limits were typically between 10 and 60 pg of analyte. The utility of the technique for: (i) detecting abnormal distributions in cytosolic metals due to metal exposure; and (ii) determining the biological turnover of Cu and other metals associated with proteins is demonstrated using the marine shellfish Littorina littorea exposed to elevated concentrations of Cd and 65Cu.
Metals IEC HPLC SEC Mass spectrometry Speciation

"Continuous-flow Analysis In Chemical Oceanography: Principles, Application And Perspectives"
Sci. Total Environ. 1986 Volume 49, Issue 1 Pages 27-87
Laurence D. Mee

Abstract: A review over 25 years is presented, with 219 references, on the development of automated segmented flow analyzer.s and flow injection analyzer.s for data acquisition in oceanography. With modern instrumentation, 11 organic and 26 inorganic constituents were determined in seawater at 120 samples per hour at the 0.1 µM level.