C Research on Mercury
7. Development in Mercury Analysis

Past(before 1960)

Colorimetry (analysis of total mercury)

Total mercury can be analyzed by density of orange color of mercury-dithizone complex.
About 1/1,000,000 g (1 microgram) of mercury is detected by this method.

Present (NIMD Method)

Atomic absorption method(analysis of total mercury)

Mercury vapor originated from the mercury-containing samples can be detected by its specific ultraviolet absorption.
To vaporize mercury (mostly in a form of mercuric compound) in the samples, (i) reductive method and (ii) combustion method are employed.
Less than 1/1,000,000,000 g (1 nano gram) of mercury can be detected by this method.

ECG-GC method(analysis of methylmercury)

Methylmercury in the sample solution must be extracted into organic solvent such as toluene prior to analysis.
Methylmercury chloride in the toluene solution can be detected by ECG-GC (Electron-Capture Detector-Gas Chromatography).
Less than 1/10,000,000,000 g (0.1 nano gram) of mercury can be detected by this method