毛細電泳及氣/液相層析電灑法質譜於環境污染物及動物用藥分析技術之開發與應用

Development and Application of Environmental Pollutants and Veterinary Drug Residues Analysis by CE/ESI-MS, LC/ESI-MS and GC/ESI-MS

洪偲華(Sih-Hua Hung)

指導教授 ： 何國榮

國立臺灣大學/理學院/化學研究所/博士(2013年)

https://doi.org/10.6342/NTU.2013.02118

摘要

鹵乙酸(Haloacetic acids (HAAs))為自來水經加氯消毒處理所產生的消毒副產物，本研究藉由流動注入分析搭配場放大樣品堆積-毛細電泳電灑法二次質譜(FI-FASS-CE-ESI-MS/MS)即時偵測自來水中HAAs的含量變化，並結合線上去鹽步驟降低自來水中的鹽類，使得鹵乙酸的訊號可獲得300-1400倍提昇。分析自來水中鹵乙酸的方法偵測極限，除了一氯乙酸為1 ppb (使用選擇離子偵測模式)之外，其他四種鹵乙酸的偵測極限約為10-100 ppt。藉由長時間(六個小時)分析實驗室自來水中鹵乙酸含量，證實FI-FASS-CE-ESI-MS/MS可以即時分析水中鹵乙酸含量的變化。此外，台北市的自來水中鹵乙酸的含量，分別為1.7ppb TCAA、1.15 ppb DCAA、0.16 ppb DBAA和 0.15 ppb MBAA。
分析高極性的氨基醣苷類化合物常添加七氟丁酸離子對試劑以提昇高極性化合物於逆相液相層析的分離解析度。本研究開發大體積進樣(LVI)技術結合電泳淌度控制(EMC)裝置，提升氨基醣苷類化合物的感度，同時減緩減緩七氟丁酸於質譜訊號抑制。利用傳輸管將液相層析與一體式電泳淌度控制裝置銜接，藉由施加正向電場於銜接管，使得帶正電荷的分析物可以往質譜方向移動，同時七氟丁酸陰離子則停留於槽內不會進入銜接管，減緩七氟丁酸對訊號的抑制。具有分流設計的一體式電泳淌度控制裝置搭配傳輸管與銜接管間保留300 μm的空隙，可讓高流速的液相層析分析得以銜接於奈灑系統的電泳淌度控制裝置，並且避免後端液相層析的高流速影響銜接管內離子的移動情形。藉由電泳淌度控制裝置，分析物的訊號可獲得6-86倍的提昇。分析策略結合大體積進樣(LVI)技術，氨基醣苷類化合物可以濃縮在液相層析管柱的前端，然後直接進行液相層析質譜/質譜分析，利用LVI-LC-EMC-MS/MS分析物可獲得462-6792倍的訊號提昇。此外，使用大體積進樣技術可取代離子對固相萃取(ion-pair SPE)，簡化牛奶樣品的前處理步驟，利用LVI-LC-EMC-MS/MS分析牛奶中氨基醣苷類化合物時，方法偵測極限為0.11-1.5 ng/mL，方法精密度(RSD(%), N=3)為10-15%。
目前分析環境中鄰苯二甲酸酯類污染物主要以氣相層析質譜為主，然而以氣相層析分析DINP及DIDP時，DINP與DIDP會形成滯留時間交疊的兩叢訊號，且質譜圖的訊號以鄰苯二甲酸酐(phthalic anhydride)離子m/z=149為主，所以無法使用最強的碎片離子訊號進行定量，導致DINP與DIDP的感度無法與單一結構的鄰苯二甲酸酯類的感度相同。利用氣相層析銜接電灑法質譜(GC-ESI-MS)分析鄰苯二甲酸酯類複雜支鏈異構物(DINP和DIDP)時，DINP與DIDP主要以分子離子形式帶電，因此可藉由DINP和DIDP的分子離子質量不同，區別異構物之間重疊的波峰。以GC-ESI-MS/MS分析複雜支鏈異構物的偵測極限約為25-50 ppb，而分析單一結構的鄰苯二甲酸酯類的偵測極限大約為1-5 ppb。目前土壤中鄰苯二甲酸酯類污染物檢測方法使用GC/MS，因土壤組成複雜，需要進行繁瑣的萃取純化步驟，不僅耗時且大量的萃取溶劑易導致背景干擾上升。利用GC-ESI-MS/MS分析土壤中PAEs時，使用DCM作為萃取溶劑，土壤樣品只需要經過超音波萃取步驟，可有效將PAEs從土壤中萃取出來，此外，藉由氣相層析法的高分離解析度以及電灑法質譜質譜的高靈敏度，可簡化土壤樣品前處理步驟，萃取液不需要濃縮處理，不僅降低背景干擾問題，同時保有良好的感度。

關鍵字

即時偵測 ； 線上前濃縮 ； 毛細電泳電灑法質譜 ； 電泳淌度控制 ； 七氟丁酸 ； 大體積進樣 ； 液相層析電灑法質譜 ； 鄰苯二甲酸酯類 ； 氣相層析電灑法質譜

並列摘要

Haloacetic acids (HAAs) belong to an important class of regulated disinfection by-products. In this study, we proposed a strategy based on flow injection and field amplified sample stacking-capillary electrophoresis-electrospray ionization-tandem mass spectrometry (FASS-CE-ESI-MS/MS) to monitor HAAs in tap water. Tap water was passed through a desalination cartridge before FASS-CE-ESI-MS/MS analysis to reduce sample salinity. With this treatment, the signals of the HAAs increased 300 to 1400-fold. The LODs for tap water analysis were in the range of 10-100 ng/L, except for the LOD of monochloroacetic acid (1 μg/L in SIM mode detection). Continuous monitoring of HAAs in tap water from Taipei City demonstrated the feasibility of the proposed approach for real-time analysis. Four HAAs, including trichloroacetic acid (TCAA), dichloroacetic acid (DCAA), dibromoacetic acid (DBAA) and monobromoacetic acid (MBAA), were detected at concentrations of approximately 1.74 ppb, 1.15 ppb, 0.16 ppb, and 0.15 ppb, respectively.
Aminoglycosides are highly polar compounds, and thus are usually analyzed using reversed phased liquid chromatography with addition of HFBA ion pairing reagents. A strategy based on large volume injection (LVI) and postcolumn electrophoretic mobility control (EMC) was developed to increase the sensitivity of aminoglycosides analysis and to alleviate the adverse effect of haptafluorobutyric acid (HFBA) on the liquid chromatography-electrospray ionization mass spectrometry (LC-ESI-MS) analysis. An integrated EMC device with splitting design consist two junction reservoirs, an ESI sprayer and a short connecting capillary (1 cm). With the use of a transfer capillary for connecting HPLC to integrated EMC device and applying an electric field across connecting capillary, positive charged aminoglycoside migrated toward the MS whereas HFBA anion remained in the junction reservoir preventing from ion suppression during ESI process. With splitting design and a 300 μm interval between transfer capillary and connecting capillary, the integrated EMC device can adapt for high flow rate (0.2 mL/min) LC analysis. Under optimized conditions of integrated EMC device, signals for aminoglycosides were enhanced 6-86-flod without compromising separation efficiency. Coupling large-volume injection (LVI) technique with ion-pair LC-EMC-MS/MS, aminoglycosides were extracted in the column head and directly eluted to MS with preventing HFBA ion suppression and the signal enhancement were in the range of 462-6792 fold. To demonstrate the feasibility of LVI-LC-EMC-MS/MS on signal improvement, the milk analysis of aminoglycosides was performed and the LODs were obtained in the range of 0.11-1.5 ng/mL with the precision about 10-15%.
The environmental analysis of phthalates is established based on gas chromatography mass spectrometry (GC/MS). The analysis of di-isononylphthalate (DINP) and di-isodecylphthalate (DIDP) by GC results in an unresolved cluster of peaks that all predominated fragment to the phthalic anhydride ion at m/z = 149. Consequently, quantification of DINP and DIDP using the most abundant ion is impossible and the same sensitivity as for the single isomer phthalates cannot be reached. Gas chromatography coupled with electrospray ionization-mass spectrometry (GC-ESI-MS) was used to analyze the DINP and DIDP. Because of soft ionization characteristic of ESI, DINP and DIDP were ionized as molecular ions as the base peak. This provided easy discrimination among the phthalates on the basis of their molecular weight. Furthermore, with tandem MS performed, the sensitivity of analysis phthalates was improved. The detection limit of complex mixtures of isomers, DINP and DIDP, were about 25-50 ppb and single isomers were about 1-5 ppb using GC-ESI-MS/MS method. The method was also applied to measure phthalate in soil. The sample pretreatment was simplified by sonication using dichloromethane without complicated extraction and purification. The high efficiency of phthalates analysis in soil was obtained by coupling GC high separation resolution with ESI-MS/MS high selectivity and sensitivity.

並列關鍵字

real-time analysis ； in-line preconcentration ； CE-ESI-MS ； electrophoretic mobility control ； HFBA ； large volume injection ； LC-ESI-MS ； phthalates ； GC-ESI-MS

參考文獻

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