Because articles that come in contact with human skin should be free of harmful materials and allergenic substances, new regulations for consumer protection are in the works to restrict the content of lead (Pb), cadmium (Cd) and other toxic or allergenic elements in fashion jewelery, watch parts, and accessories, as well as in the metal fastenings and ornaments on handbags, wallets or clothing. This analytical challenge requires measuring equipment that can quickly and easily detect even the tiniest amounts of these substances.
Under this new regulation, not only harmful organic substances but also heavy metals, in particular Pb, Cd and Ni, should be severely limited. Depending on the industry and country, the threshholds can be extremely low, often in the range of 100 ppm.
For cost purposes, the metal parts in fashion jewelery and accessories are not always made of solid materials. The underlying forms are made of easily workable, inexpensive alloys which are then plated with decorative coatings. Both the coatings and the substrate materials must be free of Pb and Cd. Therefore, it is most time and cost effective to analyze such base materials as brass and zinc alloys prior to shaping and coating.
In contrast to the huge effort required with chemical analysis, it is straightforward and simple to test for contaminants using X-ray fluorescence (XRF) systems. Their high detection strength and low detection limits – indispensable in any measurement method – make the XRF-systems from FISCHER ideal for such screening purposes.
|Matrix||Std. dev. Pb [ppm]|
|Brass, actual||10 - 30|
|SnBi2, actual||5 - 15|
|SnBi50 actual||50 - 100|
The standard deviation of repeated measurements is a direct indication of the lowest concentrations detectable by an instrument (detection limit ~ 3 x std. dev.). The impressive results in Table1 show that the XRF method and the FISCHERSCOPE® X-RAY XDV®-SDD are exceptionally well suited for trace analysis – and therefore, for controlling whether legal target values have been met.
Worldwide, FISCHERSCOPE® X-RAY XDV®-SDD instruments are in use for the screening of materials used in the manufacture of fashion jewelery and accessories. These instruments are characterized by their easy handling and their excellent repeatability precision and are therefore best suited to oversee the compliance of new regulations. Your local FISCHER agent will gladly assist you with further questions.