ASTM D5384 Standard Test Methods for Chlorine in Used Petroleum Products (Field Test Kit Method)
3. Summary of Test Methods
3.1 The oil sample (approximately 0.3 g) is dispersed in a hydrocarbon solvent and reacted with a mixture of metallic sodium catalyzed with naphthalene and diglyme at ambient temperature. This process converts organic halogens to their respective sodium halides. Halides in the treated mixture, including those present prior to the reaction, are then extracted into an aqueous buffer, which is then titrated with mercuric nitrate using diphenyl carbazone as the indicator. The end point of the titration is the formation of the blue-violet mercury diphenylcarbazone complex.
3.1.1 Preset reagent quantities are used for Method A so that the final result is clearly determined to be either above or below 1000 mg/kg total chlorine.
3.1.2 A fixed concentration titrant of mercuric nitrate in water is used for Method B. A titration is performed on the extracted aqueous sample until the color changes from yellow to blue. At this point, the titration is stopped and the chlorine concentration is determined based on the volume of titrant added. (Warning - In case of accidental breakage onto skin or clothing, wash with large amounts of water. All the reagents are poisonous and should not be taken internally.) (Warning - The gray ampules contain metallic sodium which is a flammable, water-reactive solid. Reaction with water will generate flammable hydrogen gas.) (Warning - In addition to other precautions, do not ship kits on passenger aircraft. Kits contain metallic sodium and mercury salts. Used kits will pass the USEPA Toxic Characteristic Leaching Procedure (TCLP) test. Check with your state environmental enforcement office to see if additional disposal regulations may apply.) (Warning - When the sodium ampule in either kit is crushed, oils that contain more than 25 % (m/m) water will cause the sample to turn clear to light gray and will build noticeable pressure. Under these circumstances, the results can be biased excessively low and should be disregarded. (Warning - In addition to other precautions, take care to ensure that fingers are not cut by glass in the kits. All reagents in pre-packaged kits are contained in crushable glass ampules inside plastic test tubes. Each ampule should be crushed only once to reduce the risk of glass pieces piercing the sides of the tube. Wear safety glasses and gloves throughout the testing procedure.)
4. Significance and Use
4.1 Chlorinated compounds can lead to corrosion of equipment and poisoning of the catalyst. Chlorinated compounds also present a health hazard when incompletely combusted. Chlorine content of petroleum products is determined prior to their being recycled.
NOTE 1 - Federal Regulations mandate that often the chlorine content of used oil must be determined before recycling.
4.2 These test methods can be used to determine when a used petroleum product meets or exceeds requirements for total halogens measured as chloride. It is specifically designed for used oils, permitting on-site testing at remote locations by nontechnical personnel to avoid the delays of laboratory testing.
