83
Dissolved Organic Matter in Natural Waters
Compound
Use
Structure
Precursor ion
Collision energy (eV) Product ion pKa a
Trimethoprim
Antibiotic
291 [Μ
+ Η] +
−17.5
261
7.20
Thiabendazole
Antibiotic
202 [M
+ H]
+
−23.0
175
Caffeine
Stimulant
195 [Μ
+ Η] +
−16.0
138
Sulfamethoxazole
Antibiotic
254 [Μ
+ Η] +
−13.0
156
5.81
Metoprelol
Anti-hypertension
268 [M
+ H]
+
−15.5
191
9.17
Propranolol
Anti-hypertension
260 [Μ
+ H]
+
−11.0
116
9.14
Diphenhydramine
Antihistamine
256 [Μ
+ H]
+
−11.5
167
8.76
Diltiazem
Anti-hypertension
415 [M
+ H]
+
−22.0
178
8.94
Table 3 (continued)
(continued)