精品一区二区三区-精品一区二区三区91-精品一区二区三区爱爱视频-精品一区二区三区东京热-精品一区二区三区东京热不卡-精品一区二区三区国产视频

您好!歡迎訪問廣州艾欣科學儀器有限公司網站!
全國服務咨詢熱線:

13724099587

當前位置:首頁 > 資料下載 > EPA1664—己烷提取物的檢測

EPA1664—己烷提取物的檢測

發布時間:2013/6/23      點擊次數:8482

 1) Assemble

a) Assemble cartridge adapters on the vacuum manifold

b) Place ECUNIOGXF cartridge(s) on each vacuum station needed

c) Connect the manifold to a suitable trap and attach the trap to a vacuum system capable of

attaining a minimum of 25” Hg (635 mm) of vacuum

d) Insert waste collection vial in manifold (optional)

2) Prepare Water Sample

a) Adjust the pH of the sample to less than 2 by adding 5 mL of 6N HCl or 2.5 mL of concentrated

H2SO4

b) If acid was added to the sample in the field do not add more unless the pH is greater than 2

Gloves are recommended as skin oils may affect final sample weight

3) Condition the Cartridge

a) Rinse sides of cartridge and bottle holder with 10 mL of hexane

b) Allow cartridge to soak for 1 minute

c) Draw the hexane through the cartridge using vacuum

d) Discard the hexane from waste vial

e) Draw full vacuum through the cartridge for 2 minutes to dry

f) Add 10 mL of methanol to the cartridge

g) Slowly draw the methanol through leaving a layer on the cartridge frit

h) Soak for one minute

i) Remove waste vial and discard methanol

From this point on do not let the cartridge dry out otherwise repeat at step f)

j) Add 30 mL of DI water to the cartridge

k) Draw the water through the cartridge to waste

4) Sample Addition

a) Add the 1 liter water sample directly to the cartridge

b) Draw the sample through the cartridge under low vacuum. This may take several minutes

depending on the solids in the sample. (Note 1) Increase vacuum pressure if necessary. Do

not exceed 500 mL/minute

c) Remove the cartridge and tap any excess water from the bottom of the cartridge

d) Replace cartridge and allow to dry under full vacuum for 10 minutes

e) Remove any water remaining in the bottom support of the cartridge with a paper towel if

necessary

5) Elution

a) Prepare an extract collection vial containing about 8 mm (0.3 inch) of anhydrous sodium

sulfate

b) Place the vial in the manifold station under the cartridge

c) Rinse the water sample bottle with 10 mL of hexane

d) Add the hexane to the cartridge

e) Soak cartridge for 2 minutes

f) Turn on vacuum and slowly draw the hexane through the cartridge and into the collection vial

g) Turn off vacuum then repeat steps 5 c) – f) 2 additional times but use 10 mL of hexane

h) Do not allow the solvent to splash into the collection vial

i) Add another 10 mL of hexane to the cartridge, rinsing the bottle holder

j) Soak cartridge for 2 minutes

k) Draw the hexane through the cartridge

6) Dry the Extract

a) Remove the collection vial from the manifold and cover with a screw cap

b) Shake the extract to form a water/hexane emulsion and immediay pour the extract through a

sodium sulfate funnel or column containing approximay 40 g of anhydrous sodium sulfate

held in place with a glass wool plug or frit. Do not use filter paper

c) Collect the extract in a clean, pre-weighed vessel

d) Rinse the collection vial with hexane and add it to the sodium sulfate. This will rinse the vial

and the sodium sulfatez

7) Gravimetric analysis

a) Carefully evaporate the hexane using a TurboVap® or similar evaporator at 40° C until the

extract just reaches dryness.

Note: Do not over dry or low recoveries will result

Do not dry on a hot plate or in an oven or over dry as low recoveries may result

b) Allow to cool to room temperature in a desiccator before weighing

c) Record this weight as the mass per unit volume of oil and grease and report as HEM as mg/L

Notes

1) If very high solids are present, add glass wool to the cartridge prior to extraction to prevent clogging and improve

flow. The glass wool must be thoroughly rinsed as part of the cartridge during the elution step.

2) Stearic acid must be in solution in the spiking solution or low recoveries will result. If small crystals are present in

the spiking solution, sonicate or shake until dissolved.

DCN-118170-


文件下載    
廣州艾欣科學儀器有限公司
地址:廣東省廣州市天河區元崗街道元崗路天河慧通產業廣場A1棟六樓1604(總部)
傳真:86-020-36536169
關注我們
歡迎您關注我們的微信公眾號了解更多信息:
歡迎您關注我們的微信公眾號
了解更多信息
主站蜘蛛池模板: 亚洲国产成人精品女久久久 | 亚洲av日韩精品一区二区三区 | 亚洲精品国产啊女成拍色拍 | 亚洲日韩中文字 | 亚洲欧美另类日韩综合 | 91欧美激情一区二区三区成人 | 国产精华液一线二线三线 | 无码人妻精品一区二区三区东京热 | 亚洲国产成人久久综合野外 | 日本高清视频色惰www无不卡 | 综合无码一区二区 | 精品日韩中文字幕 | 国产精品亚洲一区在线播放 | 欧美影院首页 | 国产xxxxxx农村野外 | 四虎精品国产永久在线观看 | 在线播放免费人成毛片乱码 | 国产av无码专区亚洲精品 | 国产高清成免费视频 | 99久久国产综合精品1 | 国产黄毛片久久久久久 | 亚洲va中文字幕久久无码一区 | 国内精品伊人久久久久777 | 国产伦精品一区二区三区网站 | 黄色网站哪里可以看 | 人人狠狠久久综合亚洲婷婷 | 无码午夜国产成人影院 | 精品国产9 | 九色91popny | 韩国欧美三级在 | 国产不卡精品一区二区三区 | 午夜爱爱免费视频体验区 | 成人午夜福利免费体验区 | 99精品一区二区免费视频 | 国产微胖av在线播放 | 精品无码不卡中文字幕 | 午夜播放器app2025最新 | 成人无码免费视频97 | 精品国产群3p在线观看91 | 亚洲变态另类av首页 | 国产成人精品午夜二三区 |