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: Environmental -> sediment -> pond

Citations 5

"Determination Of Lead By Hydride Generation Inductively Coupled Plasma Mass Spectrometry"
Anal. Chim. Acta 2000 Volume 419, Issue 1 Pages 65-72
Jinxiang Li, Fang Lu, Tomonari Umemura and Kin-ichi Tsunoda

Abstract: A method for the determination of lead by hydride generation inductively coupled plasma mass spectrometry was explored using oxalic acid-ammonium cerium(IV) nitrate-sodium tetrahydroborate as the reaction matrix and a homemade hydride generator. The sensitivity achieved was ~7.5 times higher than that obtained using an ultrasonic nebulizer. The detection limit (3s) and the signal precision (RSD, n=13) were 0.007 µg L-1 and 0.21% for 1 µg L-1 Pb, respectively, Fe(III) or Ni(II) up to 10 mg L-1 did not affect the hydride generation of 1 µg L-1 Pb. Additionally, the present system equipped with an injector valve and a 500 µl sample loop was also operated in the flow injection mode. Because of the short memory effect (typically 25-30 s), six replicate injections of a solution containing 4 µg L-1 Pb were performed within 5 min. The RSD values (n=13) were 0.33 and 1.41% for peak height and area measurements, respectively. The method was applied to the determination of lead in three environmental reference materials involving natural water, plant tissue and pond sediment. Good agreement was obtained between the certified values and the experimental results with the precisions (RSD, n=5) less than 1.0% for both continuous and flow injection modes.
Lead Mass spectrometry Interferences Volatile generation Reference material Method comparison

"Trace Metal Enrichment By Automated Online Column Preconcentration For Flow Injection Atomic Absorption Spectrometry"
Anal. Chim. Acta 1989 Volume 221, Issue 1 Pages 65-76
Shizuko Hirata, Kazuto Honda, Takahiro Kumamaru

Abstract: Trace metals were pre-concentrated on a micro-column (7 mm x 4 mm) of Muromac A-1 (50 to 100 mesh) at a flow rate of 5 mL min-1. Ions were eluted with 2 M HNO3 (4.85 mL min-1), before analysis by flame AAS. Optimum pH was established for metal ion uptake from sample solution The coefficient of variation for 20 mL samples containing 5 to 100 µg L-1 of Cd, Cr, Cu, Fe, Mn, Pb or Zn were 0.7 to 1.7% (n = 3 or 4). Values for Cd and Cr in standard reference materials of plants, mussel tissue and pond sediment were within the specified range.
Cadmium Chromium Copper Iron Manganese Lead Spectrophotometry Column Preconcentration Muromac Reference material Optimization pH

"Determination Of Phosphorus In Turbid Waters Using Alkaline Potassium Peroxodisulphate Digestion"
Anal. Chim. Acta 1995 Volume 315, Issue 1-2 Pages 123-135
L. Woo and W. Maher*

Abstract: The evaluation of the use of alkaline peroxodisulphate digestion with autoclaving or microwave heating for the determination of total phosphorus in turbid lake and river water is described. Procedures were evaluated by the analysis of suspensions (20, 50 and 100 g P/l) of two standard reference materials, National Institute of Environmental Science, Japan No. 3 Chlorella and No. 2 Pond Sediment. Suspensions were prepared by adding these materials to distilled deionized water (pH 6) and homogenisation using shaking, sonification and stirring. Best recoveries of phosphorus were found when the final solution was 0.045 M in potassium peroxodisulphate and 0.04 M in sodium hydroxide and solutions digested in an autoclave at 120°C for 60 min. or heated in a microwave oven at 450 W for 10 min. Complete recoveries of phosphorus (99-103%) from 20, 50 and 100 g P/l Chlorella suspensions were obtained using both autoclave and microwave heating. For the Pond Sediment complete recoveries of phosphorus (99-107%) from the 20 and 50 g P/l suspensions were obtained using both heating methods. Higher recoveries from the 100 g P/l Pond Sediment suspensions were obtained using microwave heating (96 ± 1%) than autoclaving (88 ± 5%). Recoveries of phosphorus compounds (phosphates, and phosphonates) added to distilled deionized water and turbid lake water were near quantitative (91-117%) for both digestion procedures. Further analysis of Pond Sediment suspensions showed that complete recovery of phosphorus (98 ± 1%) from 60 g/l suspensions was achieved with incomplete recoveries (92.3 ± 0.7%, 91 ± 2% and 91 ± 1%) from 70 g P/l, 80 g P/l and 90 g P/l suspensions respectively. Comparison with the APHA-AWWA WPCF, nitric-sulphuric acid digestion method showed no difference in phosphorus measurements for the microwave procedure but that the autoclave procedure gave significantly lower recoveries of phosphorus (p < 0.01), however, differences were only 2-8%.
Phosphorus Sample preparation Sample preparation Reference material Method comparison

"Comparison Of Acid Mixtures In High-pressure Microwave Digestion Methods For The Determination Of The Total Mercury In Sediments By Cold Vapor Atomic Absorption Spectrometry"
Anal. Sci. 1996 Volume 12, Issue 3 Pages 471-476
C. Y. ZHOU, M. K. WONG, L. L. KOH and Y. C. WEE

Abstract: Four acid mixtures, viz. HNO3/H2SO4, HNO3/HClO4, HNO3/HCl and HNO3/HCl/HF, were evaluated as solvents for the high-pressure microwave digestion of environmental sediments for analysis of total Hg by cold vapor AAS. Sediments were dried at 105°C for 4 h and a 300 mg portion of each was digested with 14 mL of each acid mixture (acid ratios given) in an MDS-2000 Microwave System (CEM Corp., Mathews, NC, USA) operated at 630 W power, 150 psi pressure and 200°C for 30 min. After digestion, the samples were cooled until the pressure in the vessels was reduced to 50 psi, filtered and the filtrate was diluted to 50 mL with water. A 10 mL portion of the diluted filtrate was mixed with 0.2 mL 5% KMnO4 solution and a 500 µL portion of the mixture was injected into a Perkin-Elmer FIA System interfaced with a Perkin-Elmer 4100ZL atomic absorption spectrometer (instrumental details given) for measurement of Hg absorbance at 253.6 nm. Best results were obtained with the HCl/HNO3/HF mixed acid solvent. The method was successfully applied to the analysis of three sediment reference materials, viz. NIST SRM 1645 River Sediment, NIES CRM No. 2 Pond Sediment and NRCC BCSS-1 Marine Sediment with recoveries of 92-108%.
Mercury Sample preparation Spectrophotometry Reference material Optimization

"Flavin Mononucleotide Chemiluminescence For Determination Of Traces Of Copper(II) By Continuous-flow And Flow Injection Methods"
Bull. Chem. Soc. Jpn. 1985 Volume 58, Issue 4 Pages 1137-1142
Masaaki Yamada,Hideshi Kanai and Shigetaka Suzuki

Abstract: Flow injection analysis, with chemiluminescence detection, is used to determine traces of copper(II) by means of the flavin mononucleotide-hydrogen peroxide-phosphate buffer system. This permits the determination of copper(II) more selectively than any other chemiluminescence system with a detection limit of 0.03 ng (20 pL sample injection) or 0.06 ng mL-1 (continuous sample flow). The linear range is 3 orders of magnitude, the sampling rate is 120 h-1, and the relative standard deviation is 3.1% for 1 ng Cu(II) (n=10). Iron(II) and chromium(III and VI), the strongest enhancer after copper(II), provide signals 2-3% of that for copper(II). Effect of surfactant micelles on the signal for copper is also discussed. The method is successfully applied to real samples.
Copper Chemiluminescence Micelle Interferences