Newsgroup sci.chem.analytical 6115

Directory

Subject: (no subject) -- From: Andrew Brown
Subject: RE: HPLC fraction collectors -- From: Luc_Van_Laer@msn.com (Luc Van Laer)
Subject: platinum single crystals -- From: christiane.fricke@uni-duesseldorf.de (Christiane Fricke)
Subject: FOR SALE - Misc Lab Equipment -- From: pasinola@gs.net (Carey Hogan (IS Analyst))
Subject: Sterol standards for GC/coprostanol -- From: "Edward D. Hudson"
Subject: Re: Help with inorganic titration needed. -- From: Robert Leyon
Subject: Re: [Q:] Possible to measure fluoresence at higher energy than exciatated? -- From: Robert Leyon
Subject: Re: Need Help With Analytical Chem Problem -- From: "Michael H. Jubara"
Subject: Analysis of Zinc-dialkyl dithio carbamic acids (carbamates) - any insights? -- From: jorge@pcug.org.au (Jorge Garcia)
Subject: PaH in soils -- From: "Telekom.-Kurs"
Subject: Re: Response to ISO 9000 -- From: Philip Todd
Subject: FREE pH measurement booklet -- From: Bob Conner
Subject: What is EAXFS? -- From: Yourname@somwhere.COM (Your Name)

Articles

Subject: (no subject)
From: Andrew Brown
Date: 13 Nov 1996 18:01:36 GMT
A free pH booklet is available which contains valuable information on 
basic pH measurement theory, pH measurement techniques, selecting the 
proper pH electrode for a particular application, and a pH  
troubleshooting guide.  The booklet is available from Lazar Research 
Labs. Inc. by emailing service@lazarlab.com or faxing 1-213-931-1434.  
The booklet can also be obtained from the Lazar web site at 
http://www.lazarlab.com
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Subject: RE: HPLC fraction collectors
From: Luc_Van_Laer@msn.com (Luc Van Laer)
Date: 13 Nov 96 19:36:42 -0800
You could try out the Gilson Fraction Collectors. Some of their 
models can collect into a rack with funnels that lead to big vessels 
that you can put underneath the instrument.
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Subject: platinum single crystals
From: christiane.fricke@uni-duesseldorf.de (Christiane Fricke)
Date: 13 Nov 1996 11:34:09 GMT
Hello everybody,
I am looking for platinum single crystals of different sizes. Can you tell me 
where I could buy such crystals and what do they cost.
Please mail to:
christiane.fricke@uni-duesseldorf.de
Thanks in advance for your help.
Christiane Fricke 
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Subject: FOR SALE - Misc Lab Equipment
From: pasinola@gs.net (Carey Hogan (IS Analyst))
Date: Thu, 14 Nov 1996 00:32:37 GMT
These are surplus items in an off-facility storage bay for sale to
highest bidder.   This stuff will probably go cheap.  Have much more,
write and ask.
Please contact C. Hogan at pasinola@gs.net  Louisiana area.
Bay	Number 	              Item
Condition
220	1	Oven, med, VWR, model 1320		Fair
220	1	Typerwriter, IBM, Selectric		Good
220	1	File Cabinet, 3drawer			Fair	
220	2	Table, small				Good	
220	1	Centrifuge,large	Baxter			Exc
220	2	File Cabinet, 4 drawer			Fair
220	1	Oven, large				Fair
234	1	Fan, exhast, roof	Dayton			Fair
234	2	Supply, voltage regulator			Good
234	4	Cabinet, flamable storage, med		Good
234	2	Cabinet, flamable storage, med		Good
234	2	Hood, fume, 8 ft				Good
234	12	Cabinet, wall and floor, assorted		Fair
234	1	Still, Barnstead				Good
238	2	Furnace, Thermolyne, model FA10520P	Fair
238	1	Locker, Personal, 12 compartment	Good
238	8	Shelves, storage				Good
238	1	Cabinet, shelves with sliding doors	Fair
238	1	Hood, fume, 4 ft				Fair
238	5	File Cabinets, 4 drawer			Fair
242	1	Hood, fume, self contained		Good
242	12	Shelves					Fair
242	1	Reverse osmosis system			Good
242	1	Autoclave				Good
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Subject: Sterol standards for GC/coprostanol
From: "Edward D. Hudson"
Date: Wed, 13 Nov 1996 20:41:07 -0330
Dear All,
	Does anyone out there know if anyone offers a mixed sterol
standard suitable for GC (either in the free or TMS ether forms)?  
I'm looking at analysing sediment trap samples to determine 
quantities of individual sterols.  I could make up a standard 
from pure individual sterols, but if someone offers a ready-made
mixed standard, it would be easier.  Thanks in advance.
	While I'm at it- anyone know if there was ever a "last word"
in the debate on the value of coprostanol as a fecal marker?  (Some
report it as an unambiguous sewage marker, others say it may also be 
formed by bacterial delta-5 hydrogenation in sediments/sinking 
particles, still others try to get around this by quoting ratios of
coprostanol to other sterols, etc., etc. )
Thank you.  Cheers,
			Ed  :)
Ed Hudson
Department of Chemistry
Memorial University of Newfoundland
St. John's, NF A1B 3X7, Canada
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Subject: Re: Help with inorganic titration needed.
From: Robert Leyon
Date: Wed, 13 Nov 1996 20:01:18 -0500
The earlier reply (I deleted it so I don't have the author) was right, I'd
say.  The NaOH-H2O2 mixture will oxidize the organic compound and the
halogens will end up as -1 ions, which will react nicely with silver ions. 
Robert Leyon
Department of Chemistry
Dickinson College
Carlisle PA 17013
On 10 Nov 1996, Dwayne Sauka wrote:
> The question I need help with is an inorganic titration. The question 
> wants to know why the titration samples were worked up with hydrogen 
> perioxide and NaOH? The samples were dibromo and 
> dichloro-bis(diphenylphoshino)ethane. The titration standard was AgNO3. 
> The pupose of the titration was to determine the halogen content in the 
> samples.
> Any help or insight greatly appreciated.
> Many thanks!
> 
> ps- please e-mail any help to me at dsauka@unixg.ubc.ca
> 
> 
> 
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Subject: Re: [Q:] Possible to measure fluoresence at higher energy than exciatated?
From: Robert Leyon
Date: Wed, 13 Nov 1996 20:10:12 -0500
Yes, it is possible.  Look up anti-Stokes fluorescence lines in a textbook
of physical chemistry or instrumental analysis.  They are produced when
the excitation is from an excited vibrational level in the ground
electronic state to the lowest vibrational level in the excited electronic
state; then the emission is to the lowest vibrational level of the ground
electronic state.  
-- Dr. Bob 
Department of Chemistry
Dickinson College
Carlisle PA 17013
On Tue, 12 Nov 1996, R. Oestereich wrote:
> In an fluorescence experiment with deluted human blood
> I made a very strange observation: I found a peak in
> the emission spectra (Ex 460, Em 350), which is at a 
> higher energy than my excitation energy was.
> Does this mean I found a perpetum mobile? 
> Or are there any other effects?
> 
> 
> 
> With best regards,
> R. Oestereich
> 
> 
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Subject: Re: Need Help With Analytical Chem Problem
From: "Michael H. Jubara"
Date: Wed, 13 Nov 1996 10:25:29 -0800
Andrea Melissa Macdougall wrote:
> 
>         I have received the following problem as part of an analytical
> chemistry assignment, and I don't know where to begin!  Any help would be
> greatly appreciated!
> 
>         "In Agatha Christie's 'The Mysterious Affair at Styles', Mrs.
> Ingelthorpe, a wealthy elderly widow marries Alfred who is 20 years her
> junior.  One night, Mrs. I. dies in her bed with a seizure.  She was
>         Again, thank-you for any help!  Please e-mail me at:
> 
>                                 ammacdou@acs.ucalgary.ca
> 
>                                 Andrea
Lose no sleep my dear. Take a bromide-but not from the butler. That cad
obviously slipped the old dear a mickey. How so? Add the KBr to the
strychnine solution, shake and allow to settle. The result is a bottle 
containing a supernatant liquid and a ppt of nasty stuff(if taken in 
large doses). Every day the poor dear takes a dose of the liquid (neither
shaken nor stirred, please) which does her neither harm nor good. Ah, but
that last day she pours herself a dose of wet strychnineKBr (75mg if it 
is all there). Call the mortuary and Mrs. Marple. 
We of course assume that you meant 65mg rather than 65g in the old 
biddies body.
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Subject: Analysis of Zinc-dialkyl dithio carbamic acids (carbamates) - any insights?
From: jorge@pcug.org.au (Jorge Garcia)
Date: Thu, 14 Nov 1996 09:48:57 GMT
Some medical grade latex (natural rubber) materials contain traces of
Zinc-dialkyl dithio carbamic acids sometimes also refered by the name
of their carbamate form - eg diethyl dithiocarbamate.
These compounds are toxic and can lead to an inflammatory healing
response in patients. We have been trying to develop a method based on
HPLC for the detection of these compounds in rubber extracts. We have
been trying to reproduce the work described in the literature without
success.
Has anybody reading this got any experience with these compounds? Is
there any suggestions/pitfalls we should be aware of?
We've been trying Normal phase chromatography using silica columns
(yes it's a pain) - as these compounds tend to be insoluble in water,
making RPLC difficult (RPLC normally utilises water/polar organic
solvent mixtures) : Typically 80-90% heptane i: isopropanol at 1
ml/min using a 25 cm 5um silica (Spherisorb) column.
Any comments appreciated
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Subject: PaH in soils
From: "Telekom.-Kurs"
Date: 14 Nov 1996 08:32:12 GMT
Hello everybody,
I'm looking for people with experiences in preparation of soil for paH
analysis.
Special questions about drying temperature and pollution of soil by paH during
the preparation.
Thanks, Anna Jablonkay
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Subject: Re: Response to ISO 9000
From: Philip Todd
Date: Wed, 13 Nov 1996 12:28:56
In article: <3288184D.7AA2@netcom.ca>  Vanda  writes:
> 
> Let me share my ISO 9002-94 experience with you. I worked as a QA
> manager for research and analytical laboratory. Since 1991 we worked 
to
> comply with US GLP (Good Laboratory Practice) - mandatory for 
recognized
> laboratories servicing pharmaceutical or environmental clients. Than 
I
> started to work 
loads snipped
> ISO Guide 25 is only guide (to explain how to address ISO procedure 
in
> lab - but you will still be audited to ISO 9002, not to guide - here 
I
> am quoting the registration body). 
> 
> I hope this information helps. Good luck.
> 
> 
This seems to have been a fairly painless experience. However, the 
registration body is incorrect when talking about ISO Guide 25. This 
is not a guide to implementing ISO 9002 for a laboratory. It is a 
separate quality system that is similar to ISO 9002, but superior in 
some aspects eg great emphasis is placed on validation of methods, 
even if you're only implementing a standard method. ISO Guide 25 is 
usually implemented in each country under a different name - in the UK 
it is called NAMAS (National Accreditation of Measurement and Sampling 
..I think).
It sounds as if you're registration body aren't too familiar with this 
guide - hardly surprising considering the range of companies that they 
look at.
There.. that's my two pennies worth .
(p.s. couldn't be bothered converting to cents)
-- 
______________________________________________________________________
Philip Todd                            Leverton-Clarke Ltd
(All opinions are personal)            Unit 16, Sherrington Way
                                       Lister Road Industrial Estate
                                       BASINGSTOKE. Hampshire
                                       United Kingdom RG22 4DQ
                                       Tel: +44 1256 810393
______________________________________________________________________
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Subject: FREE pH measurement booklet
From: Bob Conner
Date: 14 Nov 1996 12:01:35 GMT
A free pH booklet is available which contains valuable information on 
basic pH measurement theory, pH measurement techniques, selecting the 
proper pH electrode for a particular application, and a pH  
troubleshooting guide. The booklet is available from Lazar Research Labs. 
Inc. by emailing service@lazarlab.com or faxing 1-213-931-1434.  The 
booklet can also be obtained from the Lazar web site at 
http://www.lazarlab.com
Return to Top
Subject: What is EAXFS?
From: Yourname@somwhere.COM (Your Name)
Date: 14 Nov 1996 12:23:24 GMT
Do anybody know which kind of method is EAXFS?
I've never heard it. 
Thank you in advance.
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