identification: 1, cholesteryl docosahexaenoate; 2, cholesteryl eicosapentaenoate; 3, cholesteryl linolenate; 4, cholesteryl arachidonate; 5, unknown; 6, campesteryl arachidonate; 7, avenasteryl linoleate; 8, sitosteryl arachidonate; 9, cholesteryl linoleate; 10, cholesteryl palmitoleate, 11, campesteryl linoleate; 12 and 13, unknown; 14, sitosteryl linoleate; 15, avenasteryl oleate; 16, unknown; 17, cholesteryl oleate; 18, unknown; 19, cholesteryl palmitate; 19, campesteryl oleate; 20, unknown; 21, sitosteryl oleate; 22, unknown LC/MS conditions: Hewlett-Packard model 1084 liquid chromatograph interfaced with Hewlett-Packard model 5985B mass spectrometer via a Hewlett-Packard direct liquid inlet interface; column, reversed-phase Supelcosil C (25×0.26cm i.d.);

doi:10.1201/9780203913413-42

Chapter

identification: 1, cholesteryl docosahexaenoate; 2, cholesteryl eicosapentaenoate; 3, cholesteryl linolenate; 4, cholesteryl arachidonate; 5, unknown; 6, campesteryl arachidonate; 7, avenasteryl linoleate; 8, sitosteryl arachidonate; 9, cholesteryl linoleate; 10, cholesteryl palmitoleate, 11, campesteryl linoleate; 12 and 13, unknown; 14, sitosteryl linoleate; 15, avenasteryl oleate; 16, unknown; 17, cholesteryl oleate; 18, unknown; 19, cholesteryl palmitate; 19, campesteryl oleate; 20, unknown; 21, sitosteryl oleate; 22, unknown LC/MS conditions: Hewlett-Packard model 1084 liquid chromatograph interfaced with Hewlett-Packard model 5985B mass spectrometer via a Hewlett-Packard direct liquid inlet interface; column, reversed-phase Supelcosil C (25×0.26cm i.d.);

Chapter

identification: 1, cholesteryl docosahexaenoate; 2, cholesteryl eicosapentaenoate; 3, cholesteryl linolenate; 4, cholesteryl arachidonate; 5, unknown; 6, campesteryl arachidonate; 7, avenasteryl linoleate; 8, sitosteryl arachidonate; 9, cholesteryl linoleate; 10, cholesteryl palmitoleate, 11, campesteryl linoleate; 12 and 13, unknown; 14, sitosteryl linoleate; 15, avenasteryl oleate; 16, unknown; 17, cholesteryl oleate; 18, unknown; 19, cholesteryl palmitate; 19, campesteryl oleate; 20, unknown; 21, sitosteryl oleate; 22, unknown LC/MS conditions: Hewlett-Packard model 1084 liquid chromatograph interfaced with Hewlett-Packard model 5985B mass spectrometer via a Hewlett-Packard direct liquid inlet interface; column, reversed-phase Supelcosil C (25×0.26cm i.d.);

ABSTRACT

Figure 10 shows an LC/MS elution profile of steryl esters of the LDL+HDL fraction of plasma from a patient with phytosterolemia (see Figure 8 for GLC profile). In this instance the signal from the steryl esters could be increased by performing the analysis in presence of chloride ions, which amplified the ion current (101). The total ion current and the single-ion mass chromatograms extracted from the total ion current are shown in relation to the corresponding steroid nuclei of cholesterol (m/z 369), campesterol (m/z 383), stigmasterol (m/z 395), and avenasterol and sitosterol (m/z 397). The steryl ester peaks were identified by their relative retention times when compared to synthetic standards. The total ion current represents the sum of the [MH-RCOOH]+ ion currents of the individual steryl esters.