Cadmium is a silvery-white, lustrous, but tarnishable metal; it is soft and ductile and has a relatively high vapor pressure. Cadmium is nearly always divalent; chemically it closely resembles zinc and occurs by isomorphism replacement in almost all zinc ores.(1) Most commonly it is found as the sulphide, also known as greenockite or cadmium blend, which is often associated with the zinc ore, sphalerite (ZnS is economically recoverable only when found in this form or associated with other non-ferrous metal ores, such as those of lead and copper. Canadian zinc ores contain from 0.001 to 0.067 percent recoverable cadmium; zinc concentrates normally include 0.1 to 0.3 percent cadmium, but levels up to 0.7 percent are known.
Cadmium is soft enough to be cut with a knife, but it tarnishes in air. It is soluble in acids but not in alkalis. It is similar in many respects to zinc but it forms more complex compounds.
As part of our automotive parts analysis and cadmium testing services, CMTL performs RoHS testing; the aim of the RoHS directive is to restrict certain dangerous substances commonly used in electronic and electronic equipment.
Any RoHS compliant component is tested for the presence of Lead (Pb), Cadmium (Cd), Mercury (Hg), Hexavalent chromium (Hex-Cr), Polybrominated biphenyls (PBB), and Polybrominated diphenyl ethers (PBDE).
About three-fourths of cadmium is used in Ni-Cd batteries, most of the remaining one-fourth is used mainly for pigments, coatings and plating, and as stabilizers for plastics. Cadium has been used particularly to electroplate steel where a film of cadmium only 0.05 mm thick will provide complete protection against the sea. Cadmium has the ability to absorb neutrons, so it is used as a barrier to control nuclear fission. Quantitative determination of cadmium can be performed using a variety of methods and techniques, including:
- Atomic absorption with either a graphite furnace or flame)
- Inductively coupled plasma techniques (ICP) using optical emission spectroscopy (ICP-OES) or atomic emission spectroscopy (ICP-AES,
- Mass spectrometry (ICP-MS,
CMTL offers a range of analytical methods for cadmium testing, including ICP-AES and ICP-MS. The choice of the detection procedure is based on various parameters, including quality data requirements and sample media.
ICP/AES and ICP/MS are the most commonly used instruments for testing both biological materials and environmental samples
Much progress has been made in the development of cadmium testing methods for faster detection of trace levels of cadmium in children's jewelry have become a major issue for consumers, legislators, the media, manufacturers, suppliers, and retailers offering fashion jewelry to the public.
With concerns over the millions of pieces of children's metal jewelry recalled for hazardous levels of heavy metals over the past few years cadmium testing has become more prevalent in the marketplace.
