This method is for determining total mercury in liquid hydrocarbons using a Nippon Instruments Corporation (NIC) Mercury Analyzer. The lower limit of quantitation is 0.1 ng/mL (m/v-ppb). The results can be converted to mass-ppb. Appendix A contains a procedure, Determination of Mercury Species in Hydrocarbons, which can be used to differentiate between elemental mercury, organic non-ionic mercury and ionic (both inorganic and organic) mercury species. Appendix B contains an alternative procedure for total mercury in liquid hydrocarbons, using different equipment from the same manufacturer with higher sensitivity. Refer to UOP Method 938-10 and earlier versions when using the NIC SP-3D Mercury Analyzer.