Table 4. MRM transitions, retention time, relative retention time of 18 analytes (calculated with respect to Sulphadimethoxine, IS), and optimized ESI-MS/MS parameters.

S. No	Analytes & Molecular Mass (Da)	ESI mode	Q1 mass (Da)	Q3 mass (Da)	Retention Time (min)	Relative Retention Time (min)	DP (V)	EP (V)	CE (V)	CXP (V)
1.	Cefdinir (395.0)	(+)	396.0	227.0	6.86	0.77	80	10	20	6
				126.0			80	10	42	10
2.	Cefalexin (347.1)	(+)	348.1	106.1	7.24	0.81	70	10	39	9
				158.1			70	10	14	14
3.	Cefradine (349.1)	(+)	350.1	176.1	7.68	0.86	66	10	19	5
				158.1			66	10	14	4
4.	Cefixime (453.0)	(+)	454.0	285.0	8.10	0.91	78	10	22	8
				126.0			78	10	44	11
5.	Cefaclor (367.0)	(+)	368.0	106.0	6.68	0.75	73	10	35	8
				174.0			73	10	19	4
6.	Cefotaxime (455.0)	(+)	456.0	167.0	7.52	0.84	65	10	27	4
				396.0			65	10	16	6
7.	Cefadroxil (363.1)	(+)	364.1	114.1	3.85	0.43	60	10	28	10
				208.1			60	10	16	5
8.	Cefazolin (454.0)	(+)	455.0	156.0	7.81	0.87	66	10	22	13
				323.0			66	10	16	14
9.	Ceftriaxone (554.0)	(+)	555.0	396.0	7.60	0.85	60	10	19	13
				167.0			60	10	37	15
10.	Cefsulodin (532.1)	(+)	533.1	123.1	3.10	0.35	60	10	25	7
				185.1			60	10	35	12
11.	Cefoperazone (645.1)	(+)	646.1	143.1	8.23	0.92	99	10	54	7
				290.1			99	10	31	6
12.	Cefoxitin (427.1)	(-)	426.1	156.1	8.11	0.91	-65	-10	-13	-6
				112.1			-65	-10	-24	-4
13.	Cefalothin (396.0)	(-)	395.0	180.0	9.17	1.03	-71	-10	-20	-9
				167.0			-71	-10	-9	-6
14.	Ceftazidime (546.1)	(+)	547.1	167.1	6.74	0.75	61	10	37	8
				468.1			61	10	19	21
15.	Cefuroxime (424.1)	(-)	423.1	207.1	7.67	0.86	-65	-10	-20	-11
				318.1			-65	-10	-14	-7
16.	Cefepime (480.1)	(+)	481.1	167.1	3.91	0.44	71	10	35	8
				396.1			71	10	19	16
17.	Ceftiofur (523.0)	(+)	524.0	241.0	9.26	1.04	100	10	26	6
				126.0			100	10	61	11
18.	Ceftaroline fosamil (684.0)	(+)	685.0	208.0	7.97	0.89	108	10	55	6
				262.0			108	10	50	7
19.	SDM (IS) (310.0)	(+)	311.0	156.0	8.94	-	70	10	28	7