Trace Lead Measurement and Online Removal of Matrix Interference in Geosamples by Ion-Exchange Coupled with Flow Injection and Hydride Generation Atomic Fluorescence Spectrometry
Table 2
The operating program of the FI ion-exchange system.
Step
Times (s)
Pump rate (ml)
Valve position
Description
Pa
Pb
Pa
Pb
0
180
180
3.5
0
0
Pa is active, sample load and lead are preconcentration in columns a, and b
1
1
1
0
0
0
Pa stops; sample loops dip into water
2
10
10
3.5
0
0
Water pushes the remain sample of the loop to pass through the columns
3
5
5
0
2
1
Pb is active; remain water of the loop is pushed out by air
4
1
1
0
0
1
Pa stops; sample loops dip into the eluent
5
20
20
0
2
1
Pa drives eluent to pass through b and a in series
6
20
20
0
7
1
Pb and Pc are active; sample is reacted with NaBH4 and pushed to AFS for determination.
