PROBLEMS AND SOLUTIONS IN
MEASURING EXCHANGEABLE
Ca, Mg AND K IN SOIL SAMPLES
Paulina DróVdV
Laboratory of Forest Environment Chemistry
Forest Research Institute
Poland
Meeting of the Heads of the Laboratories, 19-20 September 2013 Zadar, Croatia
Problem
�Short stability of plasma
Solution
�Barium chloride for rinsing
(f.e. between samples) instead
of water
�Manual determination instead
of sequence automation
(autosampler) to make sample
flush time shorter and
eliminate water rinsing
water BaCl2
ICP �OES iCAP 6000 series Thermo Scientific
Problem
�Short stability of
calibration
Solution
�Check and control
calibration (f.e. after 10
samples)
- quality control check (QC)
- blank
- blind sample
�Recalibrate QC failed lines
(after recalibration repeat
samples from last QC
checked)
Purity of barium chloride !
Quality Control Check before and after RecalibrationQuality Control Check before and after Recalibration