Natural Science Forum / Chemistry / Analytical Chemistry / April 2007

I'm currently restoring a Finnigan MAT GCQ with Finnigan GC back to
service. I'm using 99.999% helium bought from Praxaix as carrier gas
for the GC and as damping/vent gas in the MS. The air/water mass spec
looks sort of OK. The peak for H2O+, N2+ and O2+ are all well over

I have a reduced volume quartz cuvette with the path lenght in one
direction of 10 mm and the path length in the other direction reduced.
For fluorescence measurment, can this kind of reduced-volume cuvette
cause multiple scattering or inner filter effects? I mean compared

Dear everyone
Is there anyone who have a method of  PBBS analysis in polymer by GC/
MS?
Please inform me about that.

There are mainly two design of cuvette: all side clear and two-side
frosted.
usually the cuvette for measuring absorption have two sides frosted.
However, four sides are clear if measuring fluorescence by

I'm new to IGOR Pro and need some assistance.
I've graphed some voltammograms and need to find the maximum current.
How do you find the max and min of a graph in IGOR Pro? I've tried
searching the help section with no luck.

I have some trouble with the Heavy Metals analytical method, as
described in Ph.Eur. 2.4.8 Method F.
It states that:
"The test is invalid if the reference solution does not show a brown

I want to measure % of K in solutions using our ICP facility.
Unfortunately i see that K lines can be affected by argon lines. Can
someone suggest me the best line to be used. I see that these lines
are quite week if compared with argon lines. My final result can be

Does anyone know the level of melamine found in the pet food(s) by the
FDA?
It is probably PPM but it is just a pain that they do not give a level!

Looking for a roommate. Stay there from June 2nd to June 8th.