Samples that contain salt present a challenge for TOC analysis. Salt, even in low concentration in typical seawater (3 – 4 %) can cause devitrification of a quartz combustion tube operating at high temperature. Additionally, salt can coat the surface of the catalyst and prevent the catalytic conversion of organic compounds to carbon dioxide. Eventually, salt crystallization in the system will require increased maintenance. Numerous schemes have been employed on TOC systems to deal with salt. These range from elaborate salt traps, ceramic combustion tubes, special kits, and the use of sulfuric acid. These approaches add to the cost of the system, and in the case of sulfuric acid, may lead to poisoning of the catalyst.