One of my Student is working on quantitative estimation of Mercury in cosmetics. Unfortunately, AAS is not working. Is there any other method to detect quantity of mercury i.e, any spectrophotometric or colorimetric method??
Mercury forms a complex with dithizone (DTZ), that can be detected photometrically due to its absorbance at 490 nm. Depending on their concentration, other metals might interfere with your measurements though. Please see the following publication for details.
Dear Mussarat Jabeen, what type of AAS do you use? For low-level concentration, mercury (Hg) can't be detected by AAS only. You must tandem the AAS with Hydride Vapor Generator (HVG). It is a technique in which a reduction step is employed to convert certain elements (in this case, Hg) to volatile metal hydrides. It provides enhanced sensitivities, reduced interferences, and extremely low detection limits for mercury.
Or, you can use other spectroscopy, such as ICP OES or ICP MS.
I'm fully agree with Prif. Lingjian Gao, that you can use the reliable method CVAFS "cold vapor atomic fluorescence spectrophotometer" that is a little difficult but fit for any mercury levels, and another system direct mercury analyzer (DMA) which is easier but it's working only for low Hg content. The key point is that both of them for analysing total mercury (THg) not elements as Hg.