Drying under reduced pressure
(For the Intramural)
<Summary of changes as of April 1st 2017>
- We will charge a fee for "drying under reduced pressure" process
even if a sample is lost during the process and it is impossible to carry
out a CHN measurement.
- The fee is calculated by 30 minutes (30, 60, 90, 120 ... minutes) at one time.
<Description>
This method is a useful method which corrects for the influence of moisture absorption and determines exact CHN contents about a hygroscopic sample. Procedures are the following steps 1 to 7.
- A sample is weighed.
- The sample is put into a glass bell jar with a desiccant (P2O5). The sample is dried under reduced pressure (1.5 mmHg) at room temperature (25 ºC) by vacuum pump.
- Inside of the jar is filled with nitrogen gas.
- The sample is picked up from the jar, temporal change of the weight is recorded.
- CHN elementary analysis is carried out.
- Hygroscopic measure is determined by a time graph.
- An accurate result is obtained by results of 5 and 6.
We recommend that clients use the method when they want to know exact CHN contents of a hygroscopic sample. The fee is calculated by 30 minutes (30, 60, 90, 120 ... minutes) at one time.
<Notes>
- Please remove residual solvents from your sample because our vacuum pump
might be broken.
- Please check not to evaporate the sample under reduced pressure (1.5 mmHg) at room temperature (25 ºC). We may not measure the CHN analysis of the sample, if "its molecular weight is small", "it is easy to sublimate", or "its volatility is high". We will charge a fee for "drying under reduced pressure" process even if a sample is lost during the process and it is impossible to carry out a CHN measurement.
The Service Center of the Elementary Analysis of Organic Compounds, Faculty
of Science, Kyushu University
West Zone 1 #B-206, 744 Motooka Nishi-ku, Fukuoka, 819-0395, Japan
TEL/FAX : +81-92-802-6247 E-mail : 
Copyright 2004 The Service Center of the Elementary Analysis of Organic Compounds, Faculty of Science, Kyushu University