| 摘要 |
The determination of a proportion of diesel fuel in a lubricating oil of a combustion engine, comprises forming a mixture containing a sample of lubricating oil and 5C alkane, injecting the mixture into an injector of gas chromatograph, establishing a chromatograph of the sample, determining a first parameter M representative of a chromatograph peak area associated with alkane, and determining a second parameter C representing of the chromatograph peak area associated with a 20-25C alkane of the diesel fuel. The determination of a proportion of diesel fuel in a lubricating oil of a combustion engine, comprises forming a mixture containing a sample of lubricating oil and 5C alkane, injecting the mixture into an injector of gas chromatograph, establishing a chromatograph of the sample, determining a first parameter M representative of a chromatograph peak area associated with alkane, and determining a second parameter C representing of the chromatograph peak area associated with a 20-25C alkane of the diesel fuel, and determining the proportion T of diesel fuel by (C/(M)-b)/a, where a and b are the constants defined by the equation y = ax+b of a straight line calibration, which is in relation between the first and second parameters with respect to the proportion of diesel fuel. The diesel fuel content is calculated according to the second parameter C of the chromatograph. The second parameter is established by C = alpha xC0/(C5), where C0 is the hydrocarbon peak area, alpha is correction coefficient to a reference concentration, and C5 is the hydrocarbon concentration in the sample. The formed mixture comprises carbon disulfide in the predetermined proportion. Preliminary determination of the straight-line calibration equation comprises determining the parameters a and b of the straight-line calibration. Each chromatograph is established by a flame ionization detector and a calculation gives integrations of the chromatograph to calculate each peak area of the chromatograph. |
