The Japanese Testing Methods for Fertilizers (2019) lists IC NI-424 as a non-suppressor type chromatography column for the analysis of chloride in fertilizers. This method applies to fertilizers, such as “potassium sulfate”, “potassium bicarbonate”, “magnesium potassium sulfate”, “fish powder”, “fish meal”, and “compost”.
In this application, we used NI-424 to analyze chloride standard solution and potassium sulfate, one of the fertilizers included in the method. A good linearity was obtained for the calibration curve in the concentration range of 1 – 20 μg/mL chloride.
1. Weigh 1.00 g of the target sample and put it in a 200-mL Erlenmeyer flask with stopper.
2. Add 100-mL water and mix the contents for 10 minutes by placing the flask on a flask shaker.
3. Pour the supernatant into a 50-mL centrifuge tube with stopper and centrifuge at 1,700 x g for about 5 minutes.
4. Dilute the supernatant 1 + 19 fold with water.
5. Filter the mixture with a 0.45-µm membrane filter and use it as a sample.
Sample : 20 μL
Srandard 5 mg/L
Columns : Shodex IC NI-G (4.6 mm I.D. 10 mm) + NI-424 (4.6 mm I.D. x 100 mm) Eluent : 2.1 mM Phthalic acid + 2.9 mM Amino-n-capronic acid + 6 mM Phenylboronic acid aq. Flow rate : 1.0 mL/min Detector : Non-suppressed conductivity Column temp. : 40 °C