1994 Volume 43 Issue 5 Pages 425-429
Surface-enhanced infrared spectroscopy was applied to the trace analysis of residual additives on several agricultural product surfaces. The surface species were transferred onto silver-coated barium fluoride substrates by pressing the substrates. To clarify the optimum sampling conditions, the effects of the pressure and pressure time were examined with the use of model samples (polyethyleneterephthalate films coated with several amounts of silicone resin). The best obtained conditions were 200g/cm2 and 1 min.The correlation between the amounts of surface silicone and the SEIRA intensity was also studied. A good correlation was obtained between the sample amounts of 50200ng/cm2. The method was actually applied to four different cultivated fruits (lemon, grapefruit, cherry and mandarin orange). Small amounts of silicone additive were identified from the lemon, grapefruit and cherry surfaces. These fruits were produced in foreign countries.
