how to edit rawdata?

[haipu]

hi, is there any way to edit the raw data or the chromatography captured by the system like eurochrom? do i need to edit them using other software?

thanks.

[DR]

If the system is worth anything at all with respect to regulatory compliance, no. You (by design) are unable to edit raw data.

[Peter Apps]

If you have lots of time you can export raw data from some packages to ASCI or Excel files and then edit it as you want. I have never then put it back into the original software though.

Peter

[haipu]

i tried to open the raw data in a typical text editor and change a single value, but when i tried to open it in the data system again it prompt me file cannot be loaded.. it seems the raw data file is protected from changing?

[Jackus]

I know a man who is able to modify/create nearly ALL chromatograms which are secured with control checksums (Waters, Agilent). He is able to insert peak with specified spectrum (incl. noise), delete peaks,... and other miracles. It is very time-consuming work. You must be very good in programing.

[Jackus]

i tried to open the raw data in a typical text editor and change a single value, but when i tried to open it in the data system again it prompt me file cannot be loaded.. it seems the raw data file is protected from changing?

Yes, datafile is checksum protected. If you change anything, you have to generate a new checksum and write it too.

[ntruong]

Haipu wrote:

i tried to open the raw data in a typical text editor and change a single value

Haipu,
I honestly don't think this is a very good idea to fiddle with raw data. What you see is what you get. Just report it. OOS? fine. Deviation? fine. Live with the data that you generated.

[HbJ]

No programmer sane in his/her mind would allow you to (easily) change your data.

But all data files are just a (more or less) a structured stream of data. So editing is possible as these miracle checksum algos are mostly CRC, MD5 or (maybe) SHA-1. If you know the checksum algo you can change your data, regenerate the checksum and all is well (i.e. your DS won't notice).

I've had an ancient DS from DANI which wrote its data in some crappy format. I opened that can and wrote a converter to AIA so all other modern DS can read the output.

As I can write AIA I'd also be able to change any chromatogram given once it's exported to AIA. Maybe I'll open up the other formats in the future

So please note: EVERY, really EVERY data file can be changed/edited by somebody who is determined and skilled enough. I'm even considering to write an AIA editor (i.e. edit the chromatogram in terms of noise, peaks, ...) just for the sake of it. No regular chromatographic file is really secure (maybe except you lock yourself out with a TPM).

All in all I'm astonished by the reliance on some 'security by obscurity' algos.

[DR]

"real" secure systems also keep the data on servers to which you (might) have "read only" access. Only instruments (or A/Ds) & admins can add or alter files. The checksum is just one of several layers of security that very few users should be able to breach.

[Jackus]

"The checksum is just one of several layers of security that very few users should be able to breach."
Yes but my colleague I menitioned above told me that some MS data are checksum secured too but when you set them to zero, all is OK. Maybe feature how to implement backward compatibility.

[DR]

some MS data are checksum secured too but when you set them to zero, all is OK. Maybe feature how to implement backward compatibility.

If true, a vendor butt-kicking session is in order.

:: takes number, gets in line ::

[HbJ]

@Sadilek: Please give me details (even via PM).

@DR: Vendor butt-kicking is my business (sorta)

[Jackus]

@Sadilek: Please give me details (even via PM).

@DR: Vendor butt-kicking is my business (sorta)

Please be palient, I will meet him later.

[HbJ]

@Sadilek: Thanks! If I have the DS in question, I feel I'm gonna poke it