我生工背景,化学很差.最近课题需要测定细菌培养过程中氮含量的变化.查到了文献,不过是用来测植物组织中氮含量的.文献较老,我就把我认为关键的地方贴上来.

Measurement of nitrogen concentration

Reagents
All solutions were prepared with distilled water.
(a)Solution A.
Dissolve 4.8 g NaOH in water and dilute to 1 L.
(b)Solution B.
Dissolve 5 g phenol and 25 mg sodium nitroprusside in water and dilute to 500 ml.
(c)Solution C.
Dissolve 2.5 g NaOH, 1.87 g anhydrous Na2HPO4, 15.9 g Na3PO4•12H2O, and 5 ml Clorox in water, and dilute to 500 ml. Store solutions B and C in amber bottles in refrigerator and warm to room temperature before use.
(d)Ethylenedia-minetetraacetic acid (EDTA).
Suspend 1g EDTA in 100 ml water and add concentrated NaOH to pH 10, using pH meter.
(e)Digestion catalyst.
2 g CuSO4•5H2O and 30 g K2SO4. Gridding each mixture thoroughly in mortar.
(f)Standard nitrogen solution.
Dissolve 0.472 g (NH4)2SO4 in water and dilute to 1 L. Dilute 10 ml of this solution to 1 L (contains 1 μg nitrogen/ml).

Experimental
Digest 50 mg sample with 1 g catalyst and 1 ml concentrated H2SO4. Dilute to 250 ml and transfer 5 ml digest to 100 ml volumetric flask. Add 1 ml EDTA solution and 5 ml solution A. Add 10 ml solution B, followed by 10 ml solution C. Make to volume with water and measure absorbance at 625 nm after 1h. Prepare standard curve by adding varying amounts of ammonium sulfate to 5 ml filter paper digest and repeat above procedure (Standard curve is linear at concentration of 10-50 μg nitrogen). Correct all absorbance by deducting absorbance of filter paper digest that contains no added nitrogen.

问题:
diegest好像是叫"kjeldahl"反应,用来催化N化物转化为氨.文献中用来digest的sample是干的,而细菌发酵液是悬浊液.怎么做digest呢?而且温度也没有给.包括后续反应也没有给出温度.实验室没有"kjeldahl flask"可以不?说实话我以前都没有听说过这玩意儿.
高人给点意见吧,谢谢!
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