An On-Line Solid Phase Extraction-Liquid Chromatography-Tandem Mass Spectrometry Method for the Determination of Perfluoroalkyl Acids in Drinking and Surface Waters
Table 1
Elution gradients used by the loading pump and the elution pump. Elution pump flowed at 300 µL/min. Loading time was 260 s. Sample volume was 5 mL.
Time (min)
Elution pump (unchanged gradient)
Elution pump (plug gradient)
Elution pump (early gradient)
Loading pump
A%
B%
A%
B%
A%
B%
Flow (µL/min)
A%
B%
0
95
5
95
5
95
5
1200
100
0
3.00
95
5
3.99
95
5
4.00
20
80
4.34
95
5
4.50
20
80
1200
100
0
4.51
65
35
4.75
55
45
5.00
30
70
30
70
6.00
30
70
6.34
30
70
6.50
200
10
90
10.00
0
100
11.00
0
100
11.34
0
100
11.50
200
10
90
13.50
0
100
14.50
0
100
95
5
1200
100
0
14.84
0
100
15.50
95
5
95
5
15.84
95
5
16.50
95
5
95
5
1200
100
0
(A) 2 mM ammonium acetate with 5% methanol. (B) Methanol.
