UOP 952-1997 国外国际标准.pdf

TRACE LEAD IN GASOLINES AND NAPHTHAS BY GF-AAS UOP 952-97 SCOPE This method is for determining trace concentrations (10 to 400 mass/vol-ppb) of lead in gasolines and petroleum naphthas. The method has not been validated on higher boiling range materials. The method is specifically applicable to alkyl lead compounds such as tetraethyllead (TEL) and tetramethyllead (TML), other lead compounds have not been investigated. OUTLINE OF METHOD Tetraalkyllead compounds in gasoline and naphthas are converted into water-soluble lead species that are subsequently extracted into dilute nitric acid. Lead concentrations in the nitric acid extracts are determined using Graphite Furnace-Atomic Absorption Spectrometry (GF-AAS). APPARATUS References to catalog numbers and suppliers are included as a convenience to the method user. Other suppliers may be used. Atomic absorption spectrometer , with autosampler and graphite furnace capabilities, Perkin-Elmer, Model 4100ZL Balance, top loading, readability 0.01-g Cylinders, graduated, 25- and 100-mL, Fisher Scientific, Cat. Nos. 08-552C and -552E, respectively Flasks, volumetric, Class A, borosilicate glass, 50-, 100-, 200- and 1000-mL, Fisher Scientific, Cat. Nos. 10-210-5B, -5C, -5D and -5G, respectively Lamp , lead, EDL, Perkin-Elmer, Cat. No. N305-0657 Pipets, volumetric transfer, Class A, 1-, 3-, 5-, 10- and 50-mL, Fisher Scientific, Cat. Nos. 13-651-1A, - 1C, -1E, -1K and P, respectively IT IS THE USERS RESPONSIBILITY TO ESTABLISH APPROPRIATE PRECAUTIONARY PRACTICES AND TO DETERMINE THE APPLICABILITY OF REGULATORY LIMITATIONS PRIOR TO USE. EFFECTIVE HEALTH AND SAFETY PRACTICES ARE TO BE FOLLOWED WHEN UTILIZING THIS PROCEDURE. FAILURE TO UTILIZE THIS PROCEDURE IN THE MANNER PRESCRIBED HEREIN CAN BE HAZARDOUS.