Addista Multi parameter standard solution

Water quality testing. How do you make sure your analytical results are always correct?
System for Analytical Quality Assurance (AQA), consisting of one combined standard/spiking solution and two round robin test solutions.
Applicable for the cuvette tests:
- LCK153 Sulphate, 40-150 mg/L SO4
- LCK305 Ammonium, 1-12 mg/L NH4-N
- LCK311 Chloride, 1-70 mg/L Cl
- LCK314 COD, 15-150 mg/L O2
- LCK340 Nitrate, 5-35 mg/L NO3-N
- LCK349 Phosphate (ortho), 0.05-1.5 mg/L PO4-P
- LCK385 TOC, 3-30 mg/L C