Trace Mercury In Water Samples Research Articles

Solid Substrate Room Temperature Phosphorimetry for the Determination of Trace Mercury Based on the Reaction between Alkaline Phosphatase and Mercury Using Triton X‐100 as a Sensitizer

AbstractA new solid substrate room temperature phosphorimetry (SSRTP) for the determination of trace mercury has been established, using Triton X‐100 as a sensitizer. The regression equation of working curve was ΔIp=11.40m(Hg2+)+1.569 (ag·spot−1, n=6, ΔIp=Ip1−Ip2, Ip1 and Ip2 referred to the phosphorescence intensity of the blank reagent and the test solution, respectively), and correlation coefficient (r) was 0.9984. The RSD valus of the determination of 0.016 and 8.0 ag·spot−1 Hg2+ were 4.1% and 1.7% (n=8), respectively, indicating that the method had good repeatability. The limit of detection (LOD) calculated by 3Sb/k was 7.0 zg·spot−1 Hg2+ (corresponding concentration: 1.8×10−17 g·mL−1, Sb=0.025, n=11). This method has high sensitivity, selectivity and precision, which was applied to determination of trace mercury in water samples with the result being agreed very well with that of dithizone extraction spectrophotometry.

Analysis of trace mercury in water by solid phase extraction using dithizone modified nanometer titanium dioxide and cold vapor atomic absorption spectrometry

A new method for analysis of trace mercury in water samples was developed, based on the combination of preconcentration/separation using dithizone-modified nanometer titanium dioxide (TiO 2) as a solid phase extractant and determination by cold vapor atomic adsorption spectrometry (CVAAS). Dithizone was dissolved with alcohol and loaded on the surface of nano-sized TiO 2 powders by stirring. The static adsorption behavior of Hg 2+ on the dithizone-modified nanoparticles was investigated in detail. It was found that excellent adsorption ratio for Hg 2+ could be obtained in the pH range of 7–8 with an oscillation time of 15 min, and a 5 mL of 3.5 mol·L −1 HCl solution could quantitatively elute Hg 2+ from nanometer TiO 2 powder. Common coexisting ions caused no obvious influence on the determination of mercury. The mechanisms for the adsorption and desorption were discussed. The detection limit (3σ) for Hg 2+ was calculated to be 5 ng·L −1. The proposed method was applied to the determination of Hg 2+ in a mineral water sample and a Zhujiang River water sample. By the standard addition method, the average recoveries were found to be 94.4%–108.3% with RSD ( n = 5) of 2.9%–3.5%.

Microcolumn packed with YPA 4 chelating resin on-line separation/preconcentration combined with graphite furnace atomic absorption spectrometry using Pd as a permanent modifier for the determination of trace mercury in water samples

A new method using a microcolumn packed with YPA 4 chelating resin as solid-phase extractor has been developed for the separation and preconcentration of trace Hg prior to its measurement by GFAAS with Pd as a permanent modifier. Various parameters such as the amount of the modifier, pH, sample flow rate, the concentration and volume of eluent have been studied in order to find the best conditions for the determination of mercury. The detection limit of the method (3 σ) for Hg based on an enrichment factor of 100 was 0.2 ng ml −1. A characteristic mass of 114 pg was obtained for mercury using Pd as a permanent modifier. The relative standard deviation was 2.8% at the 10 ng ml −1 level ( n = 5). The method has been applied to the determination of trace mercury in environmental water samples and the recoveries for the spiked samples are in the range of 91–105%.

Determination of mercury in process and lagoon waters by inductively coupled plasma-mass spectrometric analysis after electrochemical preconcentration: comparison with anodic stripping at gold and polymer coated electrodes

A combined electrochemical-inductively coupled plasma-mass spectrometry (EC-ICP-MS) method for the determination of trace mercury in water samples is presented. It takes advantage of the electrochemical preconcentration of mercury onto a gold spiral electrode followed by ICP-MS analysis after the electrochemical reoxidation of deposited mercury in pure supporting electrolyte. The advantages of the EC-ICP-MS approach with respect to conventional ICP-MS, are the increased sensitivity and the elimination of the effect of interfering substances eventually present in the sample. EC-ICP-MS is applied to the determination of nanomolar and subnanomolar concentrations of mercury(II) ions in real samples such as process waters (from a chlor-alkali plant) and lagoon waters (from Venice channels). Analytical performances obtained by EC-ICP-MS are discussed and compared with those obtained by anodic stripping voltammetry at gold and at Tosflex-coated glassy carbon electrodes.

Determination of sub- [formula omitted] levels of mercury in water by electrolytic deposition and electrothermal atomic-absorption spectrophotometry

The determination of trace mercury in water samples by electrolytic deposition and electrothermal atomic-absorption spectrophotometry is described. Traces of mercury in water are preconcentrated by electrolytic reduction and deposition on a platinum wire cathode, which is then put into a graphite cup for direct atomization and measurement. The method is sensitive and simple, with a detection limit of 0.04 ng ml . Almost all the metal ions commonly found in water samples can be tolerated, because of the selective deposition at controlled potential.