METHOD AND APPARATUS FOR DETERMINING impurities in oil and petroleum products

摘要

FIELD: chemistry.;SUBSTANCE: method involves automatic collection of a sample, transfer thereof into a measuring electrochemical cell, mixing with an electrolyte in form of a solution of mineral or organic lithium salts, homogenisation of the obtained mixture, electrochemical generation of silver via anodic oxidation of a generating silver electrode and successive coulometric titration of the mixture with the generated silver ions and detecting equivalence points through a potentiometric technique using a silver-selective indicator electrode. The apparatus has a chamber with a mixer and nozzles for feeding and removal of liquids, wherein the chamber consists of two linked electrochemical cells lying one below the other. The lower part of the housing accommodates a generating cell with two horizontally fitted plate electrodes, the bottom one of which is the cathode and is made from platinum, and the top one is made from silver and has a hole for linking with the measuring electrochemical cell lying above, which includes an ion-selective measuring electrode and a comparison electrode.;EFFECT: high accuracy and reliability of determination.;7 cl, 8 ex, 4 tbl, 2 dwg