At this site we are posting discussions concerning 199Hg NMR standards. We welcome all comments about, and additions to, this page. We will try to update it as notes intended for posting are sent to us. Since you are visiting this site you are probably aware of the tragic death of Dr. Karen Wetterhan, which was apparently caused by exposure to dimethylmercury. According to press accounts, exposure occured upon transfer of this liquid to an NMR tube while making an NMR reference standard. Apparently a few drops passed through the latex gloves she was wearing (see NOTE about gloves below). Since then, there have been several letters to Chemical and Engineering News containing suggestions and requests for the NMR community to adopt a new, less toxic 199Hg standard. On this page we will outline some of other methods of referencing 199Hg chemical shifts, as well as compounds that may serve as alternative references. Although the compounds presented here are easier to handle than dimethylmercury, some can still be hazardous to handle. In each case, investigators are recommended to review the material safety data sheets (MSDS) that accompany all chemicals before handling the material and to review the chemical permeability of the gloves to be worn. We will also post other investigators findings and suggestions here as we receive them.