環保專案成果報告查詢系統

專案計畫編號	EPA-101-1603-02-01
經費年度	101
計畫經費	1,619 千元
專案開始日期	2012/03/07
專案結束日期	2012/12/31
專案主持人	施養信
主辦單位	環檢所
承辦人	鄭先佑
執行單位	國立台灣大學農業化學系
專案分類	水質保護
中文關鍵字	工程奈米微粒;動態光散射技術;流力層析;分析技術;團聚;沉降;穩定性;正辛醇水分配係數
英文關鍵字	engineered nanoparticles;dynamic light scattering;hydrodynamic chromatography;analytical technology;aggregation;sedimentation;stability;octanol-water partition coefficient
協同主持人
共同主持人
計畫聯絡人	賴彥君
計畫聯絡電話	02-33669442#
計畫聯絡信箱	s1350241@hotmail.com

中文摘要	使用兩種商用奈米懸浮液polystyrene及TiO2進行樣品溫度保存實驗。建議以低溫不受陽光照射之保存條件較為適當。在實驗干擾的部份，水體中大顆粒物質、酸鹼度、鹽類以及腐植物質，均會造成顆粒粒徑顯著改變，建議注意奈米材料之等電點是否接近水中酸鹼值，避免鹽類以及腐植物質等因素干擾，盡速分析之。為排除DLS量測易受大顆粒干擾之特性，使用離心前處理方法，最佳條件為轉速4060 G時間2分鐘，即可有效將奈米級polystyrene與微米級TiO2混合液的分離，並得到83%的polystyrene回收率；同樣條件分離奈米級TiO2與微米級SiO2混合液，得到81%奈米級TiO2的回收率。流力層析可有效分離500 nm 與50 nm polystyrene混合液，計算奈米級polystyrene回收率可達87.1%；至於將微米級polystyrene等體積加入奈米級TiO2中，去離子水調整至pH 10作為移動相，可使奈米TiO2在系統中較穩定流動，則可得到78%的奈米級TiO2回收率。探討檢測方法之分析品質，粒徑分析品質與濃度分析的部份，經過前處理方式分離後之量測結果均獲得相當好的重複性與再現性，並有相當高的準確度與精密度。在自來水、水庫水、放流水以及廢水實際水樣中，由於奈米polystyrene較為穩定，因此在實際水樣中皆呈現懸浮的狀態，皆可有效分離出來，回收率皆高於80%。至於奈米TiO2，在四種水體中皆會聚集而沉降，上清液中依然懸浮的奈米二氧化鈦在放流水中甚至只有0.529 ppm，此低濃度造成分離與粒徑分析上的困難。水體環境參數影響的部份，酸鹼度對於奈米polystyrene之粒徑變化並無顯著之影響，但對於奈米TiO2而言，顆粒粒徑在接近等電點(~pH 4)有明顯的顆粒粒徑變大與沉澱現象。鹽類影響的部份，polystyrene隨著離子強度增加至350 meq/L以上時有明顯的團聚現象，臨界聚集濃度約為500 meq/L。對TiO2奈米懸浮液而言，NaCl的臨界聚集濃度約為20 meq/L。腐植酸對於polystyrene及TiO2粒徑皆無顯著的影響。關於正辛醇水分配係數Kow，奈米polysytrene的Kow值為18.67，顯示偏好分布於有機相；奈米二氧化鈦的Kow值為8.3×10-5，顯示偏好於水相。這些成果有助於幫助我們了解奈米微粒可能的生物體累積性與毒性，也助於制訂相關法規及瞭解奈米物質在環境中的分析與宿命。
中文關鍵字	工程奈米微粒;動態光散射技術;流力層析;分析技術;團聚;沉降;穩定性;正辛醇水分配係數

中文摘要

使用兩種商用奈米懸浮液polystyrene及TiO2進行樣品溫度保存實驗。建議以低溫不受陽光照射之保存條件較為適當。在實驗干擾的部份，水體中大顆粒物質、酸鹼度、鹽類以及腐植物質，均會造成顆粒粒徑顯著改變，建議注意奈米材料之等電點是否接近水中酸鹼值，避免鹽類以及腐植物質等因素干擾，盡速分析之。為排除DLS量測易受大顆粒干擾之特性，使用離心前處理方法，最佳條件為轉速4060 G時間2分鐘，即可有效將奈米級polystyrene與微米級TiO2混合液的分離，並得到83%的polystyrene回收率；同樣條件分離奈米級TiO2與微米級SiO2混合液，得到81%奈米級TiO2的回收率。流力層析可有效分離500 nm 與50 nm polystyrene混合液，計算奈米級polystyrene回收率可達87.1%；至於將微米級polystyrene等體積加入奈米級TiO2中，去離子水調整至pH 10作為移動相，可使奈米TiO2在系統中較穩定流動，則可得到78%的奈米級TiO2回收率。探討檢測方法之分析品質，粒徑分析品質與濃度分析的部份，經過前處理方式分離後之量測結果均獲得相當好的重複性與再現性，並有相當高的準確度與精密度。在自來水、水庫水、放流水以及廢水實際水樣中，由於奈米polystyrene較為穩定，因此在實際水樣中皆呈現懸浮的狀態，皆可有效分離出來，回收率皆高於80%。至於奈米TiO2，在四種水體中皆會聚集而沉降，上清液中依然懸浮的奈米二氧化鈦在放流水中甚至只有0.529 ppm，此低濃度造成分離與粒徑分析上的困難。水體環境參數影響的部份，酸鹼度對於奈米polystyrene之粒徑變化並無顯著之影響，但對於奈米TiO2而言，顆粒粒徑在接近等電點(~pH 4)有明顯的顆粒粒徑變大與沉澱現象。鹽類影響的部份，polystyrene隨著離子強度增加至350 meq/L以上時有明顯的團聚現象，臨界聚集濃度約為500 meq/L。對TiO2奈米懸浮液而言，NaCl的臨界聚集濃度約為20 meq/L。腐植酸對於polystyrene及TiO2粒徑皆無顯著的影響。關於正辛醇水分配係數Kow，奈米polysytrene的Kow值為18.67，顯示偏好分布於有機相；奈米二氧化鈦的Kow值為8.3×10-5，顯示偏好於水相。這些成果有助於幫助我們了解奈米微粒可能的生物體累積性與毒性，也助於制訂相關法規及瞭解奈米物質在環境中的分析與宿命。

中文關鍵字

工程奈米微粒;動態光散射技術;流力層析;分析技術;團聚;沉降;穩定性;正辛醇水分配係數

類型	檔名	檔案大小	說明	最新版公開日期
期末報告	EPA10116030201.DOC.pdf	4MB		2013/2/1 上午 12:00:00

摘要	In this study, two commercial NP suspensions, polystyrene (PS) and TiO2, were employed and confirmed that the size were nanoscale using transmission electron microscopy (TEM) and dynamic light scattering (DLS). The conditions for preservation of nanoparticle samples were suggested to keep in 4oC without direct sunlight. The influence of natural parameters, large particles, pH, electrolyte, and humic acid, was investigated. It showed that the particle size became larger because of aggregation or sedimentation under pH close to the pHzpc of nanoparticles, with electrolytes or humic acid. Sampling the water without adjusment of pH to the pHzpc of nanoparticles and without adding electrolytes was recommened. To avoid the interference of pH, salts and humic substance, the samples were analyzed as soon as possible. Two pretreatment processes were introduced to eliminate the interference from large particles during the particle size analysis by DLS: centrifugation and hydrodynamic chromatography (HDC). Centrifugation (4060 G, 2 min) can be used to remove large particles efficiently. For the mixture of nano-PS and micro-TiO2, it was well separated by centrifugation and the recovery of nano-PS was 83%. For the mixture of nano-TiO2 and micro-SiO2, it was also well separated by centrifugation and the recovery of nano-TiO2 was 81%. The other novel technology applied in this area is HDC. To optimize the analysis, the deionized water adjusted to pH 10 was used as eluent to maintain the stability of TiO2 nanoparticles in HDC system. HDC can well separate two PS particles around 500 nm and 50 nm PS and the recovery of nano-PS was 87.1%. The accuracy, precision, repeatability and uncertainty of DLS and two pretreatments were evaluated and showed highly analytical qualities. The influences of three main aqueous parameters, pH, electrolyte, and humic acid, on nanomaterials in water were discussed. In contrast with PS, the obvious aggregatin and sedimentation behaviors were found when the aqueous pH value was close to the pHzpc of TiO2 NPs (~pH 4). Nevertheless, the particle size of PS was significantly changed when the concentration of NaCl up to 350 meq/L. The critical aggragation concentration (CAC) value of PS was near 500 meq/L. As compared to PS, TiO2 NPs were more easily aggragated at a lower NaCl concentration about 20 meq/L (CAC value). For humic acid, it did not affect the size of PS and TiO2 NPs. For the n-octanol-water partition coefficient (Kow), the Kow of nano-polystyrene is about 18.67. It’s revealed polystyrene prefers in the organic phase. The Kow of nano-TiO2 is 8.3×10-5, nano-TiO2 prefers in aqueous phase. Our results provide important insights into the ways in which nanoparticle analysis and change under different aqueous conditions, which is generally relevant to the nanoparticle measurement and fate in diverse natural environment.
英文關鍵字	engineered nanoparticles;dynamic light scattering;hydrodynamic chromatography;analytical technology;aggregation;sedimentation;stability;octanol-water partition coefficient

摘要

In this study, two commercial NP suspensions, polystyrene (PS) and TiO2, were employed and confirmed that the size were nanoscale using transmission electron microscopy (TEM) and dynamic light scattering (DLS). The conditions for preservation of nanoparticle samples were suggested to keep in 4oC without direct sunlight. The influence of natural parameters, large particles, pH, electrolyte, and humic acid, was investigated. It showed that the particle size became larger because of aggregation or sedimentation under pH close to the pHzpc of nanoparticles, with electrolytes or humic acid. Sampling the water without adjusment of pH to the pHzpc of nanoparticles and without adding electrolytes was recommened. To avoid the interference of pH, salts and humic substance, the samples were analyzed as soon as possible. Two pretreatment processes were introduced to eliminate the interference from large particles during the particle size analysis by DLS: centrifugation and hydrodynamic chromatography (HDC). Centrifugation (4060 G, 2 min) can be used to remove large particles efficiently. For the mixture of nano-PS and micro-TiO2, it was well separated by centrifugation and the recovery of nano-PS was 83%. For the mixture of nano-TiO2 and micro-SiO2, it was also well separated by centrifugation and the recovery of nano-TiO2 was 81%. The other novel technology applied in this area is HDC. To optimize the analysis, the deionized water adjusted to pH 10 was used as eluent to maintain the stability of TiO2 nanoparticles in HDC system. HDC can well separate two PS particles around 500 nm and 50 nm PS and the recovery of nano-PS was 87.1%. The accuracy, precision, repeatability and uncertainty of DLS and two pretreatments were evaluated and showed highly analytical qualities. The influences of three main aqueous parameters, pH, electrolyte, and humic acid, on nanomaterials in water were discussed. In contrast with PS, the obvious aggregatin and sedimentation behaviors were found when the aqueous pH value was close to the pHzpc of TiO2 NPs (~pH 4). Nevertheless, the particle size of PS was significantly changed when the concentration of NaCl up to 350 meq/L. The critical aggragation concentration (CAC) value of PS was near 500 meq/L. As compared to PS, TiO2 NPs were more easily aggragated at a lower NaCl concentration about 20 meq/L (CAC value). For humic acid, it did not affect the size of PS and TiO2 NPs. For the n-octanol-water partition coefficient (Kow), the Kow of nano-polystyrene is about 18.67. It’s revealed polystyrene prefers in the organic phase. The Kow of nano-TiO2 is 8.3×10-5, nano-TiO2 prefers in aqueous phase. Our results provide important insights into the ways in which nanoparticle analysis and change under different aqueous conditions, which is generally relevant to the nanoparticle measurement and fate in diverse natural environment.

英文關鍵字

engineered nanoparticles;dynamic light scattering;hydrodynamic chromatography;analytical technology;aggregation;sedimentation;stability;octanol-water partition coefficient