Arsenic and Mercury instumental analysis in petroleum

Have you looked into x-ray flourescence spectrometers.

XRF is a common technique with little or no sample preparation and very easy to use.

Here Crude oil comes from the ground also called as Petroleum.The make-up of crude oil consists of the following elements or compounds: 84% carbon,14% hydrogen, 1 to 3% sulfur as hydrogen sulfide, sulfides, disulfides, elemental sulfur, less than 1% nitrogen, less than 1% oxygen found in organic compounds such as carbon dioxide, phenols, ketones, carboxylic acids, less than 1% metals like nickel, iron, vanadium, copper, arsenic.