Metabolomics Society Forum

Software => MS-DIAL => Topic started by: QizhiSu on May 09, 2020, 06:23:38 AM

Title: Improving the speed of opening Compound Search for GC-MS data
Post by: QizhiSu on May 09, 2020, 06:23:38 AM
Dear MS-DIAL developer,

I am thinking if it is possible to improve the speed of opening Compound Search window when dealing with GC-MS data. I am currently using NIST library. I found that it is very slow to open the Compound Search window (ca. 1). I am wondering if the problem is that Compound Search lists all entries in the library. however, most of them are not useful and might slow down the opening speed. as such, i am asking if it is possible to limit the number of entries in the Compound Search list, for example, 100 entries by default. Or, it would be great to offer users an option to choose how many entries do they want to display.

best regards.
Title: Re: Improving the speed of opening Compound Search for GC-MS data
Post by: Hiroshi Tsugawa on May 14, 2020, 01:11:27 AM
Hi,

I understand. The reason for requiring too much time in compound search is due to the lack of retention time or retention index in the NIST original library. MS-DIAL will use the retention information for searching spectra in GC-MS project as it has been done in LC-MS by the precursor m/z. However, most of users will not use retention time information or use very large value like "100000" as the retention time tolerance for annotation. That's why, the compound search function is very slow...

In my case, I predicted retention times (for my lab) and retention indexes (for Alkanes and FAMES) for all NIST and Wiley queries. The confidence interval is less than 100 for kovats RI. Therefore, I can quickly open the compound search window even thought such a huge library is imported.
https://pubs.acs.org/doi/abs/10.1021/acs.analchem.7b01010

Please ask me privately, and I can help the msp file preparation.
Thanks,

Hirsohi



Title: Re: Improving the speed of opening Compound Search for GC-MS data
Post by: QizhiSu on November 10, 2021, 02:09:05 AM
Dear Hiroshi,

I now implement a predicted retention index for all compounds as well excluding those that are not predictable, but the speed is still low. I also tried to give 10000 (RI) for all missing values. It was the same. So, I am thinking if the retention time is required as well? Or if I use retention index, so it will not consider retention time?
Title: Re: Improving the speed of opening Compound Search for GC-MS data
Post by: Hiroshi Tsugawa on November 10, 2021, 09:09:18 AM
Please tick "use retention time for filtering", then, the speed will become faster. But in fact, it should be a time consuming process... Hiroshi
Title: Re: Improving the speed of opening Compound Search for GC-MS data
Post by: QizhiSu on November 11, 2021, 01:49:13 AM
Great! big thanks!