對二氯苯生物偵測分析方法開發

A New Method for Biological Monitoring of p-Dichlorobenzene

對−二氯苯為國內常用之室內驅蟲劑，近年來，發現對−二氯苯對人類可能有致癌性及肝、腎臟毒性，目前生物偵測分析方法仍有某些缺失，因此本研究的主要目的在於建立對−二氯苯生物偵測分析方法。 本研究運用頂空固相微萃取技術進行尿液樣品前處理，並以氣相層析儀──電子捕捉偵測器（GC- ECD）同步檢測作業勞工尿液中的原化合物對──二氯苯及其主要代謝物 2,5−二氯酚。完成最佳分析條件測試後，並進行對−二氯苯勞工暴露者尿液分析，評估本方法之干擾及應用之可行性。 研究結果顯示最佳之前處理條件分別為：在 pH 7 左右的 4 mL 尿液中，添加 1.6 g 的氯化鈉，以 60℃加熱和 400 rpm 的轉速震盪尿液樣品，同時以 CW/DVB 纖維進行頂空固相微萃取 20 分鐘後，再以230℃熱脫附8 分鐘。對−二氯苯檢量線之濃度範圍為6.93～313.33 ng/mL，2,5−二氯酚檢量線之濃度範圍為 1.30～250.8 ng/mL，且兩者檢量線相關係數的 r 值均在 0.995 以上。對−二氯苯和 2,5−二氯酚的平均添加回收率分別為 97.03%和 100.53%。對−二氯苯的偵測極限及可量化偵測極限分別為 0.767 和 1.45 ng/mL。2,5−二氯酚的偵測極限及可量化偵測極限分別為 0.553 ng/mL 和 0.983 ng/mL。另對−二氯苯與 2,5−二氯酚基質效應的影響不明顯，且尿液檢體貯存在 −20℃時，可維持 30 天的穩定性。本分析方法經現場作業勞工真實尿液測試，顯示能應用於對−二氯苯作業勞工之暴露評估。本研究已成功的建立靈敏、簡單且可靠之對−二氯苯勞工暴露者之生物偵測技術。

p-dichlorobenzene is widely used as household repellent. This chemical was reported to cause health hazards, including liver, renal toxicity, and possible human carcinogen. Today, the biological monitoring method of p-chlorobenzene still has some defect. The main purpose of this study was to establish the better method for the biological monitoring of p-chlorobenzene. In this study, urine samples containing p-dichlorobenzene (parent compound) and 2,5-dichlorophenol (main metabolite) were treated by the solid phase microextraction technique, then were analyzed by gas chromatography combined with an electron capture detector. Urine samples from exposed workers were collected to further validate the interference and the application of the new method. The optimal results were obtained when 1.6 g of sodium chloride was added in the 4 mL urine sample with pH 7, stirring at 400 rpm in 60℃ water bath. Carbowax/divinylbenzene (CW/DVB) fiber was used to conduct headspace solid-phase microextraction at 20 min and thermal desorption at 230℃ for 8 min. The correlation coefficients of calibration curves of p-dichlorobenzene and 2,5-dichlorophenol were greater than 0.995 over the concentration ranges of 6.93 to 313.33 ng/mL and 1.30 to 250.8 ng/mL, respectively. Urine samples were stable for at least 30 days at –20℃. The limit of detection and the limit of quantification of p-dichlorobenzene were 0.767 and 1.45 ng/mL, respectively. The limit of detection and the limit of quantification of 2,5-dichlorophenol were 0.553 and 0.983 ng/mL, respectively. No matrix effect was found and the mean recovery were 97.03, 100.53% for p-dichlorobenzene and 2,5- dichlorophenol, respectively. Urine samples from p-chlorobenzene exposed workers demonstrated that the proposed method is applicable to real samples in field study. The developed new method can provide a sensitive, simple, and reliable method for biological monitoring of occupational exposure of p-dichlorobenzene.