LC-MS Applications for Environmental Analysis

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Personal Care Products
Caffeine (CAF)
MW: 194.19, pKa =10.4,
Stimulant
Triclocarban (TCC)
MW: 315.19,
Anti-bacterial agent
Pharmaceuticals
Carbamazepine (CBZ)
MW: 236.27, pKa=13.9,
Anticonvulsant
Clofibric acid
MW: 214.65
Metabolite lipid regulator
Naproxen (NAPRO)
MW: 230.26, pKa=4.15
Analgesic
Gemfibrozil (GEM)
MW: 250.33,
Anti-cholesterol
Salicylic acid
MW: 138.12
Metabolite of acetylsalicylic acid (aspirin)
Trimethoprim (TRI)
MW: 290.30, pKa=7.12
Anti-infective
H3C
O OH
CH3 O
CH3
CH3 H3C CH3
OH
O
O
Hormones
Estrone
MW: 270.4
Estrogen
Estriol
MW: 288.4
Estrogen
Estradiol
MW: 272.4
Estrogen
Progesterone
MW: 314.15
Progestogen
17-α-Ethinylestradiol
MW: 296.4
Synthetic estrogen
Pesticide
Atrazine (ATRA)
MW: 215.68,
pKa =1.7,
Herbicide
Figure 1: Molecular structures of selected compounds
O
H
H
H
O
O
H
H
H
O
Concentration and Extraction Procedure
The solid phase extraction procedure is illustrated in
Figure 2. Briefly, analytes were concentrated and extracted
using a 200 mg C18-like analytical cartridge. Retained
analytes were eluted from the cartridges using 3 mL
90/10 and 3 mL MeOH. They were then
collected on the conical-bottom centrifuge tube for
evaporation to dryness with N2 (g). Extracted analytes
were reconstituted to 200 µL with 90% water/formic acid
0.1% and 5% MeOH solution containing the internal
standards.