Libraries in Quantitative Analysis

Hello Justin_F ,

Here are a few community discussions that have some information on the reference library and library methods.

(+) MassHunter Quantitative method is not matching to library for specific compound - Forum - Mass Spectrometry Software - Agilent Community

(+) How is the reference spectrum generated in the Compound Information window in Quantitative Analysis? - Forum - Mass Spectrometry Software - Agilent Community

(+) MassHunter Quant Library Match Score low compared to manual search - why? - Forum - Mass Spectrometry Software - Agilent Community

There is also some useful information available in the Quant supplemental videos about these features. 

To summarize this briefly, if you just need a library match score then use a reference library, which just has one spectrum for each target. It is not search but each compound's spectrum is compared to the target compound's spectrum and a match score assigned.

If you want to have a little more control over how the reference library is used you can use a library method, which is an Unknowns Analysis method. You can also utilize the library method to extract deconvoluted spectrum and search libraries in addition to your reference library to assign alternate hits to your targets in addition to match scores.

In your specific example above regarding the match score, I would say there are several ions missing from your target, such as 71 and 83. Also the patterns below 53 are a bit different, but I can't really say if that would justify a 50 or a 90 match score. One thing to be aware of is that the libraries are cached once you open and analyze a batch. If you change the library and want to see the results of the new spectrum you will need to save your batch, exit quant, and reanalyzed. 

I am getting a method validation error when trying to set this up in another quant method I am working on: 

But this error doesn't make sense. The reference library is in the library method!? I have another method setup in a similar way that doesn't give this error. 

I am getting a method validation error when trying to set this up in another quant method I am working on: 

But this error doesn't make sense. The reference library is in the library method!? I have another method setup in a similar way that doesn't give this error. 

I was able to solve this problem by editing the Library Method within Quant to remove all other libraries except the Reference Library. Note if I tried to edit the Library method within Unknowns Analysis to removed all other libraries and save the UA method it still gave the same method validation error.