1. In relation to the ammonia solution from our experience it does not really matter what material you use we had some BDH 25% ammonia solution which we diluted down to ~ 1% with water and used this to rinse the system.
I saw on the web that there is a reagent:
Ammonia solution 25% | 105432 - Merck Millipore I am sure that would be OK.
2. Also as some others have indicated they have not seen any problems with the Ar supply causing iodine contamination and I agree from my perspective as well.
3. You indicated that your blanks stabilized around 3800 intensities. Not sure what units your system works with.
However we ran a Agilent 7500CX ICPMS and when our system was clean the best we could do for a zero calibration was around 400 - 500 cps. However sometimes we ran with zeros of around 1600 cps.
Our calibration range for iodine was 0, 1.0, 2.5, 5.0, 10, 25 & 50 ug/L and generally showed the following data:
0 ug/L = 500 cps
1 ug/L = 8900 cps
50 ug/L = 404000 cps
NOTE: We used Sb rather than Te as our internal standard because we found it more reliable for the matrices we used.
Using the Agilent software we routinely achieved an r = 0.9999 or better with a DL calculated as 0.005 ug/L.
Mr. Lyndon Palmer
Flinders University Plant Nutrition
School of Biological Sciences
South Australia, AUSTRALIA 5042
Tel. +61 8 8201 3536
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From: PLASMACHEM-L: Analytical Chem.(ICP's, DCP's, MIP's). [mailto:[log in to unmask]] On Behalf Of Mukul N. Patel
Sent: Friday, 31 March 2017 12:17 AM
To: [log in to unmask]
Subject: Re: Iodine blank values too high
Thank you for the suggestions. I am E-mailing you the request for your publication that you mentioned in the E-mail. Can you please provide the details about the ammonia, i.e. grade type, vendor etc. I shall try ammonia wash prior to TMAH diluent blank analysis.
Thank you for consideration.
Mukul N. Patel
Mukul N. Patel
Accu Reference Medical Lab
1901 East Linden Avenue, Suite 4
Linden, NJ 07036
Mobile: (732) 599-6137