Table 1.

Assay suitability. Analyses of standards were performed in triplicate and evaluated using ICH guidelines for precision (< 20 % R.SD at the LOQ, otherwise <15 %) and accuracy (< 20 % relative error (R.E.) at the LOQ, otherwise <15 %). The dynamic range was extended 2 orders of magnitude using the quadrupole MS detector in a serial configuration with the LC-TUV optical detector.

Mal-Linker-DSEA
N=3			TUV			MS
Ref. Sample	Conc. (ng/mL)	Mass load (pg)	Area	R.SD	R.E.	Area	R.SD	R.E.
				(%)	(%)		(%)	(%)
1	4406.25	22031.25	196.67	2.35	99.80	1195858	18.32	78.08
2	2203.13	11015.65	99.35	2.13	100.55	667774	11.20	87.20
3	1101.56	5507.80	50.05	1.80	100.74	358237	9.78	93.55
4	550.78	2753.90	25.53	1.75	101.66	184526	8.42	96.37
5	275.39	1376.95	12.80	3.56	99.71	94516	7.52	98.71
6	137.70	688.50	6.64	4.04	99.25	47794	6.48	99.80
7	68.85	344.25	3.20	2.14	88.35	24108	4.49	100.62
8	34.42	172.10	1.67	2.73	80.16	12057	3.17	100.53
9	17.21	86.05				6089	4.47	101.29
10	8.61	43.05				2992	4.00	99.08
11	4.30	21.50				1476	2.95	96.89
12	2.15	10.75				728	6.81	93.78
13	1.08	5.40				373	0.61	92.79
14	0.54	2.70				191	2.61	88.67
15	0.27	1.35				103	2.74	85.11
NAc-Linker-DSEA
N=3			TUV			MS
Ref. Sample	Conc. (ng/mL)	Mass load (pg)	Area	R.SD	R.E.	Area	R.SD	R.E.
				(%)	(%)		(%)	(%)
1	5468.75	27343.75	262.41	1.23	100.17	1081872	18.77	81.78
2	2734.38	13671.90	131.17	2.07	99.31	591076	14.83	89.36
3	1367.19	6835.95	66.52	2.35	99.08	311053	10.56	94.05
4	683.59	3417.95	35.87	3.50	103.49	161949	6.75	97.93
5	341.80	1709.00	18.59	4.21	100.90	82233	4.81	99.44
6	170.90	854.50	10.66	2.06	103.42	41406	3.66	100.13
7	85.45	427.25	5.61	2.62	89.68	20543	2.41	99.32
8	42.72	213.60				10409	2.77	100.60
9	21.36	106.80				5178	2.99	99.96
10	10.68	53.40				2646	2.15	101.93
11	5.34	26.70				1311	6.12	100.54
12	2.67	13.35				625	3.28	94.91
13	1.34	6.70				322	4.18	95.89
14	0.67	3.35				190	2.45	109.53
15	0.33	1.65				95	5.33	102.17