Any suggestions for the determination of trace quantities (1-10 ppm)of NH3 in a) gaseous samples containing large quantities of hydrogen and carbon monokside and b) aqueous samples. I suspect derivatization followed by GC separation might be the way to go, but can not remember the reagents and experimental procedure(s).
Help will be much appreciated.
By Anonymous on Friday, March 1, 2002 - 07:33 am:
How accurate do you need to be? Consider Draeger air sampler tubes or similar?
By Anonymous on Monday, March 4, 2002 - 02:16 am:
Anonymous (March 1)...5% relative (or better) is required. I was told Draeger tubes are not quantitative enough.
By Anonymous on Monday, March 4, 2002 - 06:43 am:
This is a very difficult analysis but has been done. The methods are proprietary. Avoid diatomaceous earth and silica packing. If you use steel columns, pacify the tubing prior to use.
If you use glass be sure no acidic active sites are found in the column. Teflon wool to terminate your column might be a good idea.
You might ask vendors who produce process applications for assistance. Also vendors who prepare calibration blends may be able to offer you suggestions.
By Anonymous on Wednesday, March 13, 2002 - 07:57 am:
For gaseous ammonia, continuous flow PID is the best way to go. However, make sure that matrix effects are accounted for; also, calibration gases are probably only availible in Nitrogen or Air.
By B.Buglio on Friday, March 15, 2002 - 05:26 pm:
For "b", aqueous sample. Can you acidify and then
assay the NH4+ by ion chromatography?
By Walter on Wednesday, March 27, 2002 - 06:56 am:
Scrub the gas samples through eluent using an impinger. Shoot the water samples directly on an ion chromatograph with a cation column. Works like a champ.
By Chaiyapon Ch on Monday, April 1, 2002 - 10:05 am:
You can ANALYST NH3 as gas by GCMS with two valves, one is gas sampling and one valve is column isolated for trap hydrocarbon and use the permination tube as standard NH3.
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