Mercury
Alpha lipoic acid (ALA) is a sulfur-containing antioxidant that acts in both aqueous and lipid fractions of cells and tissues. It helps to detoxify heavy metals, such as mercury, and it helps protect neurologic tissues, and at high enough doses it can reverse early stages of diabetic peripheral neuropathy. Typical doses are from 100–200 mg for general prevention and up to 1000 mg for diabetics with neuropathy (Hahm et al 2004). At the higher doses it also helps to control blood sugar (Jacob et al 1999). Animal studies show that ALA protects the heart mitochondria against aging effects.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2695174/

Selenium is protective against both mercury and arsenic poisoning.
http://orthomolecular.org/library/jom/1991/pdf/1991-v06n02-p067.pdf

Antagonistic interactions are particularly evident between selenium:cadmium and selenium:mercury,103,105 and between manganese:iron, zinc:cadmium, zinc:iron and zinc:copper.103,106,107 This means that high cadmium and/or mercury levels can be lowered by taking additional selenium.
http://www.orthomolecular.org/library/jom/2000/articles/2000-v15n03-p145.shtml