性欧美ⅩXX1819内谢,国产免费AV片无码永久免费,CHINESE国产AVVIDEOXXXX实拍 ,JAPANESE娇小侵犯

您好!歡迎訪問廣州艾欣科學(xué)儀器有限公司網(wǎng)站!
全國服務(wù)咨詢熱線:

13724099587

當(dāng)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(fā)布時間:2013/6/23      點擊次數(shù):8320

 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(xué)儀器有限公司
地址:廣東省廣州市天河區(qū)元崗街道元崗路天河慧通產(chǎn)業(yè)廣場A1棟六樓1604(總部)
郵箱:fighter31668@163.com
傳真:86-020-36536169
關(guān)注我們
歡迎您關(guān)注我們的微信公眾號了解更多信息:
歡迎您關(guān)注我們的微信公眾號
了解更多信息
性欧美ⅩXX1819内谢,国产免费AV片无码永久免费,CHINESE国产AVVIDEOXXXX实拍 ,JAPANESE娇小侵犯


            中文字幕人妻二区三区| 国产成人精品码在线观看网站| 八马影院2023最新电视剧大全| 国产乱人伦真实精品视频| kolopornoxxxx日本| 久久久噜噜噜久久| jiz欧美性hd大全| 国产黄色一级网站| 丁香花在线视频观看免费| 人妻人人澡人人添人人爽国产一区二| 欧美一区二区三区三州| 亚洲码欧美码一区二区三区 | 成人做爰视频WWW| 日韩精品极品在线| 国产精品久久久18成人| 国产精品 高清 尿 小便 嘘嘘| 成人av午夜| 亚洲精品无码国产| 国产精品一区二区av日韩在线 | 国产乱老熟女| 人人爱人人爽| 91香蕉久久| 欧美熟妇裸交久久久久久| 丝袜熟女精品一区二区三区| 色婷婷av一区二区三| 乳首の奶水julia| 日本孕妇大胆孕交无码| 国产偷人爽久久久久久| 国产精品高清一区二区| 日本乱偷互换人妻中文字幕| 久久久亚洲色图| 人妻少妇系列40部分| 看全黄大色黄大片| 国产韩国精品一区二区三区| 色哟哟—精品人妻| 亚洲午夜精品久久久久久app_97人| 亚洲成a人片在线观看久| 91人人妻人人澡人人爽国产网址| 少妇啪啪姿势不断呻吟av| 亚洲精品久久久久中文字幕欢迎你| 久久无码人妻精品一区二区三区|