N
X
C
O
N
S
Hal
Solvents
Natural
Products
P Si
C
C
C C
C
C
442
8 Mass Spectrometry
Dithranol (M r 226.2)
Ferulic acid (4-hydroxy-4-methoxycinnamic acid; M r 194.2)
Sinapinic acid (3,5-dimethoxy-4-hydroxycinnamic acid; M r 224.2; m/z 471,
[2M+Na] + )
Matrix Compounds in Negative Ionization MALDI Mass Spectra
3-Aminoquinoline (M r 144.2)
α-Cyano-4-hydroxycinnamic acid (M r 189.2; m/z 399, [2M+Na-2H] - )
800
750
700
650
600
550
500
450
400
350
300
250
200
150
100
50
0
227
211
195
177
OH OH OH
OH
OH
O
800
750
700
650
600
550
500
450
400
350
300
250
200
150
100
50
0
177 195
371
389
COOH
HO
O
800
750
700
650
600
550
500
450
400
350
300
250
200
150
100
50
0
23
39
208 225
414
640
471
242
288
316
COOH
HO
O
O
800
750
700
650
600
550
500
450
400
350
300
250
200
150
100
50
0
143
153
285
295
437
N
NH 2
800
750
700
650
600
550
500
450
400
350
300
250
200
150
100
50
0
144
188
290 333 377 399
COOH
CN
HO