Table 1. Accurate mass and candidate formulas of three peaks in the urine of the NPC patient.

No.	Retention time (min)	Observed mass (m/z)	Candidate formula	Theoretical mass (m/z)	Difference from observed mass (Δmmu)	Difference from theoretical mass (ppm)
1	13.4	453.1590	C25H28O5NS	453.1605	1.45	3.200
			C22H30O8S	453.1578	−1.24	−2.736
			C19H34O8S2	453.1611	2.14	4.722
			C14H33O10N2S2	453.1571	−1.89	−4.171
2	17.5	469.2268	C24H38O7S	469.2260	−0.78	−1.662
			C27H35O4NS	469.2281	1.35	2.877
			C21H42O7S2	469.2288	2.04	4.348
3	19.6	467.2111	C24H36O7S	469.2104	−0.70	−1.492
			C27H33O4NS	469.2125	1.38	2.941
			C21H40O7S2	469.2132	2.07	4.412