Introduction
Materials and methods
Materials
Hydrophilic interaction liquid chromatography–MS/MS conditions
Target compounds | Precursor ion (m/z) | Product ion(m/z) | Collision energy (V) | Minimum dwell time (ms) | Tube lens (V) |
---|---|---|---|---|---|
MOPAA | 209.088 | 74.196 | 14.31 | 65.002 | 52 |
136.042 | 14.86 | 65.002 | 52 | ||
EOPAA | 223.125 | 74.125 | 14.94 | 65.002 | 62 |
150.042 | 13.68 | 65.002 | 62 | ||
MPAA | 193.000 | 74.000 | 15.00 | 65.002 | 50 |
120.000 | 15.00 | 65.002 | 50 | ||
MOPGA | 266.000 | 99.000 | 22.00 | 65.002 | 68 |
193.000 | 16.00 | 65.002 | 68 | ||
EOPGA | 280.225 | 99.083 | 23.87 | 65.002 | 78 |
207.125 | 15.83 | 65.002 | 78 | ||
MPGA | 250.312 | 73.982 | 17.72 | 65.002 | 65 |
99.226 | 21.39 | 65.002 | 65 |
Detection limits
Pretreatment of urine
Matrix effects
Accuracy of the methods
Calculation of physicochemical parameters
Results
Optimization of HILIC–MS/MS conditions
Analysis of urine samples
Target compound | Equation | R2 | Linear range (ng/mL) |
---|---|---|---|
MOPAA | \(y= 4570.0 x + 35913\) | 0.976 | 50–1000 |
EOPAA | \(y= 11167 x + 1466.2\) | 0.982 | 5.0–1000 |
MPAA | \(y= 770.72 x + 1101.1\) | 0.988 | 5.0–1000 |
MOPGA | \(y= 2870.4 x + 1289.8\) | 0.985 | 1.0–1000 |
EOPGA | \(y= 2156.0 x + 244.80\) | 0.984 | 1.0–1000 |
MPGA | \(y= 1231.9 x + 2988.2\) | 0.989 | 7.5–1000 |
Validation of the methods
Concentration (ng/mL) | MOPAA | EOPAA | MPAA | MOPGA | EOPGA | MPGA | |
---|---|---|---|---|---|---|---|
Intra-daya | 750 | 80 ± 5.3 | 77 ± 8.0 | 76 ± 4.0 | 79 ± 11 | 80 ± 14 | 77 ± 8.5 |
75 | 106 ± 37 | 99 ± 43 | 98 ± 38 | 93 ± 40 | 91 ± 42 | 92 ± 39 | |
7.5 | – | 118 ± 5.4 | 117 ± 11 | 120 ± 4.2 | 126 ± 5.9 | – | |
Inter-dayb | 750 | 70 ± 13 | 80 ± 13 | 109 ± 31 | 79 ± 15 | 88 ± 14 | 99 ± 21 |
75 | 87 ± 42 | 107 ± 35 | 149 ± 8.5 | 103 ± 32 | 108 ± 27 | 126 ± 1.0 | |
7.5 | – | 94 ± 27 | 126 ± 5.7 | 97 ± 25 | 102 ± 19 | – |
Calculation of physicochemical parameters
pKa of OH group | log P | Molecular weight | |
---|---|---|---|
MOPAA | 6.45 | 0.34 | 208.20 |
EOPAA | 7.44 | 0.94 | 222.22 |
MPAA | 7.34 | 0.39 | 192.20 |
MOPGA | 8.80 | 0.98 | 265.29 |
EOPGA | 7.97 | 2.22 | 279.32 |
MPGA | 7.08 | 1.31 | 249.29 |
MPA | 1.54 | –0.89 | 96.02 |
EMPA | 1.93 | –0.32 | 124.08 |
IMPA | 3.89 | 0.02 | 138.10 |
iBuMPA | 2.04 | 0.24 | 152.13 |
CHMPA | 2.42 | 0.85 | 178.17 |
PMPA | 3.49 | 0.92 | 180.18 |