The issue is further complicated by the fact that the level of Sodium Chloride in the typical tests is assessed by measuring the conductivity, and in essence, the conductivity is measured by expressing it as that concentration of Sodium Chloride that would cause a given level of conductivity. The complication sets in when you realize that a molecule of Sodium Sulfate does not give the same conductivity as a molecule of Sodium Chloride. Conductivity is a function of the mobility of an ion, and mobility is affected by size, charge, and ......? So, it is simply completely unclear how you would take an ion chromatography analysis, and express it as a conductivity measurement... Rudy Sedlak RD Chemical Company ################################################################ TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c ################################################################ To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TechNet <your full name> To unsubscribe: SIGNOFF TechNet ################################################################ Please visit IPC's web site (http://www.ipc.org) "On-Line Services" section for additional information. For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 ################################################################