Methods - Ion Chromatograph
 

Ion Chromatography

Major anion analyses are performed using IonPac As15 (4mm) column, and self regenerating suppressor ASRS Ultra (4mm); sample loop is 25 μL.


Anion analyzed:
  retention time (min)
 Fluoride
3.8
  Chloride
4.5
 Nitrite
6.2
 Sulfate
7.2
 Bromide
12.6<
 Nirate
15
 Phosphate
20

Samples should be filtered through 0.45μm filters immediately after sampling and stored at 4 ºC. The shelf time of some anions is only 48 hours. The analysis is performed using calibration standard at 4 levels adjusted to concentration of the samples. Quality control and blank control is performed every 10th sample. For a full SOP click here.


Perchlorate is separated using IonPac AS16 (2 mm) column and self regenerating suppressor ASRS Ultra II (2mm) with external water mode.  KOH
Eluent
Isocratic
 65 mM
Flow rate
 <0.25 mL/min
Total time
14 minutes

Anion analyzed:
 Perchlorate
 retention time
 12.5 min

                                                            
Detection is performed with conductivity detector in water matrixes. For complex matrixes (e.g. tissue) the IC is connected to a mass spectrometer (Finnigan AQA) with an electrospray ionization source. The settings of mass spectrometer are:


Negative mode
 -ve
AQA mix
 5 V
probe temperature
 300 C

 
 
For further details on our pechlorate analyses see Dodds, et al. (2004), Anal. Bioanal. Chem. 379:881-887.

   © 2008 ASET Laboratory