Validation for Analytical Method of 8 Polycyclic Aromatic Hydrocarbons Added into Mint (Mentha arvensis Linne)

Abstract

A gas chromatography-mass spectrometry (GC-MS)method was developed for the simultaneous analysis of 8 polycyclic hydrocarbons (PAHs), including benzo[a anthracene, chrysene, benzo[a]pyrene, benzo[b]fluoranthene, benzo[k]fluoranthene, dibenzo[a,h]anthracene, banzo[g,h,i]perylene and indeno[1,2,3-c,d]pyrene in herbal medicinal plants such as mint (Mentha arvensis Linne). This method included a liquid-liquid extraction (hexane and N,N-dimethyformamide) combined by a clean-up step using solid phase extraction (SPE) on florisil cartridge before GC-MS analysis. Using a select PAH column for GC-MS analysis, an increased separation was achieved, in particular, for 8 PAHs (benzo[a]anthracene, chrysene, benzo[a]pyrene, benzo[b]fluoranthene, benzo[k]fluoranthene, dibenzo[a,h]anthracene, banzo[g,h,i]perylene and indeno[1,2,3-c,d]pyrene) in herbal medicinal plants compared to a 5-type column. Validation of the analytical method was performed on the base of specificity, limit of detection (LOD), limit of quantitation (LOQ), recovery, precision and accuracy. LOD and LOQ values of 8 PAHs were in the range of 0.18μg/kg~0.91μg/kg and 0.55μg/kg~2.76μg/kg, respectively. Relative standard deviations (RSD, %) of intra- and inter-day precisions were in the range of 2.90%~17.94% and 2.42%~26.77%, respectively. On the other hand, recoveries of 8 PAHs were in the range of 73.08~110.710%, whereas their accuracies were in the range of 73.08%~107.26%. The elimination of essential oil during extraction was investigated by comparing 2 fractions of liquid-liquid extraction between hexane faction I and hexane fraction II after N,N-dimethylformamide extraction. The reduction rates of major 7 volatile compounds such as L-menthone, isomenthone, L-(-)-menthol, pulegone, piperitone, menthyl acetate and 5-methyl-2-propan-2-ylcyclohex-3-en-1-one were 35.07 %, 44.43 %, 69.55 %, 45.67 %, 64.90 %, 24.78 % and 84.19 %, respectively. Due to using N, N-dimethylformamide solvent, essential oil contents were decreased. Consequently, the qualitative and quantitative analysis of PAHs were improved by the elimination of essential oil from medicinal plants.;본 연구에서는 정유를 함유한 천연물 의약품인 박하 (Mentha arvensis Linne)를 활용하여 benzo[a]anthracene, chrysene, benzo[b]fluorenthene, benzo[k]fluorenthene, benzo[a]pyrene, indeno[1,2,3-cd]pyrene, dibenzo[a,h]anthreacene 그리고 benzo[g,h,i]perylene 의 8 가지 다환방향족탄화수소 (polycyclic aromatic hydrocarbons, PAH)를 보다 정확하고 정밀하게 분석하기 위해 N,N-dimethylformamide 용매를 이용한 추출법을 이용한 뒤 select-PAH 컬럼을 사용하여 가스 크로마토그래피 (Gas chromatography)로 GC-MS 동시분석법을 확립하고자 하였다. 전처리 법의 유효성 검증은 특이성, 정성한계, 정량한계, 직선성, 회수율, 정밀성, 정확성의 7 가지 항목을 따라 수행하였다. 확립된 전처리 법을 이용한 유효성 검증에서 특이성은 각 물질마다 피크 (peak)가 명확하게 분리되는 것을 확인하였고, 고유의 MS spectrum을 확인하였다. 검출한계는0.18μg/kg~0.91μg/kg, 정량한계는 0.55μg/kg~2.76μg/kg으로 나타났고, 직선성은 상관계수 (R2)가 0.99 이상을 나타내었다. 반복정밀도 (RSD, %)는 2.90%~17.94%, 재현정밀도 (RSD, %)는 2.42%~26.77%로 나타났다. 그리고 회수율은 73.08%~110.70%, 정확도는 73.08%~107.26%로 나타났다. 또한, PAH를 분석하는 동안에 N,N-dimethylformamide 용매로 인해 발생하는 천연물 의약품의 정유 함량 변화를 박하를 사용해 관찰하였다. 박하의 정유 함량 변화는 l-menthone, isomenthone, L-(-)-menthol, pulegone, piperitone, menthyl acetate 그리고 3-Cyclohexen-1-one 2-isopropyl-5-methyl- 의 7 종의 주요 성분을 이용해서 관찰하였으며, 정유 함량의 감소율 (%)은 24.78%~84.19%로 나타났다.