| The dissertation was about testing nature constant of the process flavoring using relative national standard, developing new analysis methods on detecting harmful substances which was not inferred in the standards and evaluating the uncertainty of these methods.The foreword is a review about the current research status of process flavoring, harmful substances and the uncertainty.In chapter one the aroma, taste, pH value, moisture content, fat content, peroxide value was investigated using relative food additive's national standard.In chapter two the hydride generation-atomic fluorescence spectrometry and atomic absorbing spectrophotometry were used to test arsenic, mercury, lead, cadmium, and the pretreatment and the equipment which influenced the experiment were studied and determined. The optimum condition:HNO3 and H2O2 (v:v=6:2) were digestion reagent, the temperature of digestion was 210℃, the time was 25min, the concentration of KBH4 was 20g/L as reducer of generation-atomic fluorescence spectrometry, the carrier was 5% HCl. The recoveries of mercury, arsenic, cadmium were determined arranged from 99% to 110%,96% to 113%,90% to 108%, respectively, the recovery of lead which tested by the atomic absorbing spectrophotometry was determined arranged from 95% to 105%. 9 Process flavorings were analyzed by the optimizing experimental condition; and the content of mercury, arsenic, cadmium, lead were all lower than standard's limitation.In chapter three a method for the HPLC determination of 3,4-benzo[a] pyrene (B&P) in process flavoring has been developed and proposed. The pretreatment and the equipment which influenced the experiment were researched and determined, the pretreatment was C18 matrix solid-phase dispersion, the extract solvent was methanol. The column of the HPLC was Eclipse XDB-C18 (250mm×4.6mm/5μm); the mobile phase was v(methanol):v(water)=90:10 with the flow rate at 1.OmL/min; the DAD's detection wavelength was 290nm. The recovery was 77～79%, the RSD of recovery was 0.8%, the limit of detection was 18.6ng/mL.3,4-benzo[a] pyrene was positive determined in 20 samples. In chapter four a method for the HPLC determination of 2-amino-1-methyl-6-pheny-limidazo[4,5-b]pyridine (PhIP) in process flavoring has been proposed. The PhIP can be extracted from the process flavoring samples with dimethylformamide (DMF). The column of the HPLC was Eclipse XDB-C18 (250mm×4.6mm/5μm); the mobile phase was v(DMF):v(methanoI):v(water)=8:50:42 with the flow rate at 0.5mL/min; the DAD's detection wavelength was 327nm. The recovery arranged from 79% to 86%, the limit of detection was 19.2ng/mL. No PhIP was positive determined in 10 samples.In chapter five the of the method was evaluated, in which the heavy metals (mercury as a samples) were tested by hydride generation-atomic fluorescence spectrometry, the uncertainty ponderance urel(C0) of adjusting was 0.0561; the uncertainty ponderance urel(std)of calibration was 0.025; the uncertainty ponderance urel(sam) of treating with samples was 0.021; the uncertainty ponderance urel(W) of stochastic effect was 0.0008; the combination uncertainty U was 0.12μg/g; the uncertainty of mercury was±0.2p.g/g.In chapter six the of the method was evaluated, in which the B&P was tested by HPLC, the uncertainty ponderance urel(Co) of adjusting was 0.0231; the uncertainty ponderance urel(std)of calibration was 0.0077; the uncertainty ponderance urel(sam) of treating with samples was 0.0025; the uncertainty ponderance urel(W) of stochastic effect was 0.00007; the combination uncertainty U was 0.90μg/mL; the uncertainty of mercury was±2μg/mL.In chapter seven the of the method was evaluated, in which the PhIP was tested by HPLC, the uncertainty ponderance urel(C0) of adjusting was 0.0089; the uncertainty ponderance urel(std)of calibration was 0.0077; the uncertainty ponderance urel(sam) of treating with samples was 0.0018; the uncertainty ponderance urel(W) of stochastic effect was 0.00001; the combination uncertainty U was 2.5μg/g; the uncertainty of mercury was±5μg/g.
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