Economical Alternatives for High Sensitivity in Atomic Spectrometry Laboratory

The most commonly used analytical tools for determination of elements at trace levels are atomic absorption spectrometry (AAS), inductively coupled plasma, optical emission and mass spectrometry (ICP-OES and ICP-MS) and atomic fluorescence spectrometry (AFS). Although sensitive plasma techniques are becoming predominant in most of the western laboratories, AAS keeps its importance in developing countries. Simple and inexpensive ways of enhancing sensitivity will be described for laboratories equipped with only a flame AA spectrometer. Although there are many chemical preconcentration procedures to improve sensitivity of flame AAS, only some atom trapping techniques will be included here. One kind of atom trapping device is a slotted quartz tube (SQT) used for in situ preconcentration of analyte species followed by a rapid revolatilization cycle to obtain an enhanced signal. These devices provide limits of detection at a level of µg L-1. Another kind of atom trapping involves use of vapor generation technique and quartz or tungsten atom trapping surfaces. The analytical steps consist of the generation of volatile species, usually by hydride formation using NaBH4, trapping these species at the surface of an atom trap held at an optimized temperature and finally re-volatilizing analyte species by rapid heating of trap. These species are transported using a carrier gas to an externally heated quartz tube as commonly used in hydride generation AAS systems; a transient signal is formed and measured. These traps have limits of detection in the order of ng L-1

Mercury emissions from crematoria

A previous preliminary pilot study indicated that concentrations of mercury in crematoria soils might be significantly higher than controls. The source of the contamination has been assumed to be dental amalgam from cremated cadavers. Amalgam fillings contain 50% mercury, which under cremation conditions is totally vaporised and emitted from the stack either as the metallic vapour or in the oxidised form. Mercury is a cumulative poison with varying biochemical effects according to concentration and species, inter alia. Although much research has centred on the affects of dental amalgam in the living, the problems arising from disposal in the dead have been largely overlooked. This study investigated mercury emissions from crematoria by means of soil and air sampling programmes. The extent of exposure to the mercury by the crematoria workers was then determined by a hair-sampling programme. The soil monitoring and analysis programme involved five crematoria and measurements were made both by using a mercury vapour meter and flameless atomic absorption techniques. Levels in each case were significantly higher than controls and gave good overall correlation with cremation output. Air measurements varied and in one case exceeded the occupational exposure standard. In all cases the levels exceeded a proposed ambient air level goal of 1 µg m-3. Hair levels in crematorium workers were significantly in excess of controls (

Analisis Kandungan Merkuri Pada Krim Pemutih Yang Beredar Di Kota Manado

ABSTRACT Whitening cream is a mix of chemicals which whiten skin or bleach black fleck on the skin. The use of Mercury in whitening cream effects many things, such as skin color changes, and at the end cause black flecks, allergy, and irritation. The use of high dose cause permanent brain damage and cancer. The objectives of this research were to identify and determine Mercury (Hg) in some whitening creams marketed in Manado City.Sample of whitening cream were 10 samples.Identification of Mercury using color test, and Cold Vapour-Atomic Absorption Spectrophotometry (CVAAS). The results shows that five samples contains Mercury (Hg)0,0004 ppm, 0,0003 ppm, 0,0006 ppm, 0,0004 ppm, and 0,0005 ppmwithin ten samples analysis. Key words : Whitening cream, Mercury, CV-AAS (Cold Vapour Atomic AbsorbtionSpectrophotometry)