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.
Solid phase micro extraction(SPME)법의 최적조건 실험 및 SPME로 추출된 산초(Zanthoxylum schinifolium)의 휘발성 성분을 GC/MSD로 확인하였다. 휘발성 성분 추출에 자주 이용되는 동시증류추출(SDE)법으로 산초의 휘발성분을 분석하여 SP-ME 법에서 확인된 휘발성 성분과 조성비를 비교하였다. SPME 최적조건 시험에서 분자량이 적고 비점이 낮은 성분은 온도가 증가할수록 화이버에 흡착되는 양은 적게 나타났으며, 분자량이 크고 비점이 높은 성분은 추출시간이 증가할수록 흡착되는 양은 증가하였다. SPME 최적조건인 추출시간 30분과 50℃에서 분리된 휘발성 성분에서는 limonene(14.65%), geranyl acetate(11.07%), β-phellandrene(7.42%), 및 phellandral(3.08%) 등의 monoterpenoids 화합물과 caproic acid(11.99%), caprylic acid(8.01%), heptanoic acid(3.49%) 등의 지방산 화합물이 주요 성분으로 확인되었고, SDE법으로 추출된 휘발성 성분에서는 geranyl acetate(13.31%), limonene(12.81%) β-phellandrene(8.86%), trans-geraniol(5.22%) 및 caprylic acid(3.03%) 등의 화합물이 주요 성분으로 확인되었다. 지방산 성분들은 SPME법에서 높게 나타난 반면에 알코올 성분들은 SDE법보다 낮았다. SPME법은 적은 양의 시료로도 매우 신속하고 간단하게 전처리 할 수 있기 때문에 기존의 휘발성분 분석시 주로 사용한 SDE법에 비해 편리하며 경제적인 것으로 생각된다.
This study was conducted to compare the volatile flavor compounds of Artemisia annua L. after extraction by simultaneous steam distillation extraction (SDE) and solid-phase micro extraction (SPME) followed by gas chromatography-mass spectrometry (GC-MS) analysis. Via SDE and SPME processes, 79 (1,254.00 mg/kg) and 39 (488.74 mg/kg) compounds were identified respectively. The compounds extracted by SDE included 27 alcohols, 13 aldehydes, 22 hydrocarbons, 3 esters, 12 ketones, 1 oxide and 1 N-containing compound, on the other hand, using the SPME method, 7 alcohols, 5 aldehydes, 1 ester, 18 hydrocarbons, 7 ketones, and 1 oxide were extracted. The major volatile flavor compounds of Artemisia annua L. isolated by the two methods were caryophyllene oxide, -caryophyllene, camphor, -selinene, -muurolene, 1,8-cineol, (E)-pinocarveol and pinocarvone. β β γ The sesquiterpene named caryophyllene oxide was the most abundant volatile flavor compound with relative contents of 234.16 mg/kg and 195.44 mg/kg obtained by the SDE and SPME methods, respectively. Among the identified volatiles, sabinene, β-pinene, α-terpinene, γ-terpinene, yomogi alcohol, myrtenol, (Z)-nerolidol, p-cymen-8-ol and eugenol were detected by the SDE method only while (E)-anethole and α-cubebene were detected by the SPME method only. This study confirmed that the composition and contents of the volatile flavor compounds vary between different extraction methods. More volatile flavor compounds were identified using the SDE method than the SPME method.
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.
SPME device was applied to determine the THM in an aqueous solution. The 6 kinds of THM was quantitatively detemined by using GC-ECD which has the sample extracted on the SPME fiber from an aqueous solution for 10 min. The THM components were well separated from CHCl_3 to the last CHBr_3 within 13 mans at the condition. 6 kinds of the volatile halogenated organic compounds: CHCl_3, CHBrCl_2, CHBr_2Cl, CHCl_3, C_2Cl_4, and CHBr_3, showed well defined calibration graph with good linearity from a few ppb level up to several tens of ppb concentration. CHBr_2Cl and C_2Cl_4, were detected from a few samples among the 10 of river samples. CHCl_3, however, was detected in 4 sea water samples with the highest of 10 ppb among the polluted 6 positions. Trace level of CHBr_2Cl and few ppb level of CHBr_3 were also detected at the other two sample stations.
Most of the 13 rain water samples collected from 6 sampling stations were contained ppb level of CHCl_3, and also CHBr_2Cl, and C_2Cl_4 were only detected at trace level at a few rain samples among them. We could recognize the fact that our air and water environment has already been contaminated by certain volatile halogenated organic compounds through this study.