Page 105 - Analytical method for food addtives

62 Analytical methods for food additives

Reference 1 2 3 4

Detection FID at 280 ºC MS selected ion monitoring (SIM) mode. electron multiplier voltage 2200– emV 2400 FID MS selected ion monitoring (SIM) mode. m/z 105

Oven temp: 80–210 ºC, 8 ºC/min; injection port 200 ºC, N 2 carrier Injection 1 µL, temp 250 ºC; splitless flow psi. Oven temp programmed Splitless GC, direct injection 0.5 µL. Oven temperature programmed Splitless GC, temp 220 ºC; splitless flow psi. Oven temperature programmed ºC

Conditions 20 mL/min (helium) 11 90–270 ºC. 140–220 ºC (helium) 11 from 100–240

mm (i.d.) OV-1 on 100–200 mesh mm m × 0.2 m × m × mm i.d. 0.25 µm)

Column mm × 2 1.8 coiled glass with 3 % Varaport 30. Ultra 1 (cross-linked methyl-silicone gum phase, 25 × 0.33 µm) DB-Wax (30 mm, 1 µm) 0.53 HP-INNOWax (30 0.25

Summary of methods for benzoic acid in foods Sample preparation/extraction Extracted with ether and into aq NaOH and CH 2 Cl 2 . Converted to TMS esters Homogenised with water at pH 1. Extracted into ether, evaporated, added acetonitrile. For GC evaporated acetonitrile and formed TMS esters Solvent extraction with heptanoi

Table 7.1 (a) Matrix Method Foods GC Foods GC–MS (SIM) Foods GC Foods GC–MS (SIM)