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[dieter...@novartis.com]

Dear Sir
I was not active for a while, and did not receive updates, since I changed
my job, and my e-mail adress. Now I am back and would like to participate
again.

I would like to ask the community the following

1) Q0/Q1 contamination and robustness of API5000 in bioanalytics
I took over a bioanalytics group, we have one API5000 since about 2 years,
for me this is the first 5000, but I have experience with Sciex instruments
since 1991. The 4000s were quite robust, under standard bioanalytical
conditions we cleaned the skimmer (and Q0 if needed) every 6-8 weeks. Now I
have learned that the 5000 I am talking about needs a Q1 (1 not 0) cleaning
by the service peaople roughly twice a year. Samples are not more dirty
than those run on 4000s. Now my question to the community: what is the
experience wrt to frequency of serious cleaning (Q1) with the 5000 compared
to the 4000.
Typical flow rate on this 5000 is 1 mL/min, no split, but a waste divertion
( only the peak an 0.5 min before and after goes to the MS)

2) Sensitivity Agilent 6410 QQQ versus API4000 and/or 5000
Are there any serious figures around?ESI POS/NEG, APCI POS/NEG?
Head-to-head comparison, that is, same compound/solution, same LC
conditions (flow rate, mobile phase, column-type....)
Is anyone using the nano LC-Chip for quantitation with this 6410QQQ ? If
yes, what are the figures: sensitivity? robustness with real samples (e.g.
plasma), what kind of sample prep needed for e.g. plasma

Thank you in advance

Best regards


Dr. Dieter Zimmer
Group Head, ED/DMPK/Bioanalytics
CHBS, WKL-136.2.26
Novartis Pharma AG, Werk Klybeck
Klybeckstrasse 141
CH-4057 Basel
Switzerland
Phone: +41 61 6964308
Fax: +41 61 6965865
Cell: +41 79 5812024
Email : dieter...@novartis.com

[Attila.Ka...@teva.hu]

Dear Dieter,

we have an API5000 and a 4000Qtrap and do bioanalytics (plasma samples).
We can not see any difference between the two machines in contamination
vise. Our experience is that the contamination inside (Q1 and Q3) of the
MS is compound dependent, some of the compounds makes it dirty in a
relatively short time, some not contaminate it all. The 4000 is cleaned
inside in two years periods, the 5000 has not cleaned inside (nearly two
years old) and we have not seen any sensitivity loss on the latter one.
We have an API2000 and in its first 5 years it was not cleaned inside.
Then we introduced a new compound and it had have cleaned after a half
year. And it is cleaned in the two years periods since then -as for the
4000.
The Q0/skimmer (orQjet in the case of 5000) is cleaned in once/twice in
every two months in general (again depends on the compound we use). We do
not apply split and waste-switching usually, so the load on the MS is
relatively high.

Probably you could decrease the flow rate, apply higher curtain gas
setting. This helped us, but I think these hints have been tried out by
you already. Also after your batches you could run the MS with the
applied flow rate for an additional hours without injecting real samples
or injecting eluent.

So this is my experience, I will look forward for others.

I can not answer for your other question on Agilent MS because of lack of
experience.

Best regards,

Attila

Attila Kalmanczhelyi
MS analyst/scientist

dieter...@novartis.com wrote:

>1) Q0/Q1 contamination and robustness of API5000 in bioanalytics
>I took over a bioanalytics group, we have one API5000 since about 2
>years,
>for me this is the first 5000, but I have experience with Sciex
>instruments
>

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