The methods for determining the diffusion parameters for the diffusion of d-limonene, a major volatile compound of orange juice, through a multi-layered food packaging material and predicting its absorption into the packaging material have been investigated. The packaging material used was the 1.5-mm thick multi-layered packaging material composed of high impact polystyrene (HIPS), polyvinylidene chloride (PVDC), and low density polyethylene (LDPE). Orange juice was placed in a cell where volatiles were absorbed in the sample package and kept at 23±2oC for 72 hr. The d-limonene absorbed in a 1.5-mm thick multi-layered food packaging material was analyzed by a solid phase micro-extraction (SPME). The absorption parameters for the absorption of d-limonene in the packaging material were determined and absorption of d-limonene into the packaging material was predicted using absorption storage data. The SPME desorption at 60oC for 1 hr resulted in the most sensitive and reproducible results. The diffusion coefficients of d-limonene in the packaging material and the partition coefficient at 23±2oC were approximately 1-2×10-12m2/s and 0.03, respectively. The absorption profile no earlier than 30 hr was fit well by a model derived from the Fick’s law.

A rapid and simple method for the quantitative determination of volatile fatty acids (VFAs; propionic acid, n-butyric acid, i-valeric acid and n-valeric acid) and indoles (phenol, p-cresol, 4-ethyl phenol, indole and skatole) in pig slurry and dog excrement using solid-phase micro-extraction (SPME) coupled to gas chromatography was evaluated. 50/30 ㎛ DVB/CAR/PDMS (Divinylbenzene/Carboxen/Polydimethylsiloxane) fiber was used to extract the target compounds in aqueous media. Sample amount and adsorption time was standardized for the routine analysis. Detection limits were from 0.11 to 0.15 ㎍/L for VFAs and from 0.12 to 0.28 ㎍/L for indoles and the correlations observed (R2) were 0.975～1.000. This method was applied to the pig slurry, fertilizer, compost and dog excrement. In nearly all cases, the indoles were detected in concentrations of higher than their limits of detection (DOLs). But the VFAs in swine manure were below their DOLs.

The study was carried out to evaluate the new analytical method of phthalate esters(diethylphthalate, di-n -butylphthalate, butylbenzylphthalate, bis(2-ethylhexyl)phthalate), one of the endocrine disruptors, which were performed by GC/MS-SIM(selected ion monitoring). The phthalate esters were extracted from water samples using solid-phase extraction on C18 columns. It investigated that the extraction recovery rate of phthalate esters with different solvents and solvent volume. The optimal solvent was dichloromethane and proper volume of dichloromethane for recovery of phthalate esters was 4 mL. There were good linearities(above R2=0.9975) in the range 0.01～0.50㎎/L, and the detection limits were below 0.01～0.03㎍/L. The recovery rates, RSD and MDLs for phthalate esters were 80～114%, 5.0～8.1% and 0.03～0.11㎍/L, respectively. This method shows a good precision of phthalate esters.