Page 188 - Analytical method for food addtives

E249–50: Nitrites 125

18 7 12 17

ppm of NaNO 2 concentration in final solution Using enzyme solution: Nitrite assay linear 10 –8 –10 –2 M with LOD of 10 –8 M and recovery 90–107 %. Imprecision 4–10 % on entire With NiR immobilised: linear range 10 –5 –10 –2 M and LOD 10 –5 M

Detection limit 0.1 µg/mL, RSD 2–16 % 93 % recovery of nitrite. CV~8 %. Calibration curve linear between 0.2 and 1.0 calibration curve. Enzymatic assay in good agreement with results obtained using commercial nitrite determination kits Sensitivity 0.01 µmol/L with recovery of 99.6 % 1.6–6.0 % for (n=6) of 31.2 µg/mL nitrite

Method applied to real samples (n=3) Precision of method established Precision of method established Precision of method established

Spinach Meat Beer Human plasma and urine

Colorimetric Enzymatic spectrometric = suphanilamide = sulphamethizole = sulphadimidine

IC HPLC Key: SAM SM SD