Posts Tagged ‘Method Development’

Should I use LC or GC for my analysis?

Although most analysts already know which approach they need to use for analysis, this is occasionally a topic of discussion.  While this blog post is not meant to give an absolute answer for each specific application, I hope to provide some tips to steer you in the general direction towards a solution, if this is […]

Selecting a Detector for LC

Although a blog is not a good way to teach all there is to know about LC detectors, I have tried to put together information to give an overview of the most common detectors.  Restek does not sell HPLC instruments or detectors, but we think we might be able to help if you are very […]

You want them, I got them…a lot of them: pesticides GC-MS/MS transitions

I can tell you that determining transitions (SRMs) for GC-MS/MS can be quite challenging with so many precursor ions to evaluate. I spent a considerable amount of time optimizing transitions for our GC Multiresidue Pesticide Kit which has 203 compounds. That is a lot of transitions to evaluate! I also tested my chromatographic method for […]

Easy Peasy: Optimized LC-QTRAP Method for Pesticide Residues

Despite what is sometimes advertised, setting up optimized methods for multiresidue pesticide analysis is typically not “easy peasy” and can be quite time consuming. Luckily, some colleagues are willing to share their method with us. Thank you Kelli, James, and Jon!* The downloadable spreadsheet contains retention times, transitions, ionization and collision parameters for our LC […]

Great Internal Standards for Pesticide Residues…SRMs too!

  In just about all of my pesticide residue work, I use a convenient multicomponent internal standard mix that contains several PCBs as well as popular internal standard compound triphenylphosphate. The mix contains the six compounds in the chromatogram below. I have been working on a method for our GC Multiresidue Pesticides Kit which has […]

Believe to Achieve: Evaluating the Accuracy of the EZGC™ Chromatogram Modeler

As a new member of the lab, I have been working on expanding the libraries of experimental data that underly our EZGC chromatogram modeling tool. If you have never used the tool before I recommend you give it a try! It is a web based software program which, given a list of compounds, will recommend […]

EZGC Made Even Easier – Free web version now available!

A few of my colleagues, Julie Kowalski and Chris English, have written blogs about the original CD based Pro ezGC modeling software (ezGC really IS cool! and Pro ezGC Software: Manna from Heaven or a Clunky DOS-Based Program).  The basics of this software is to add a library of compounds by entering the retention times […]

Which LC Phase Do I Need?

So you’re thinking about doing HPLC (or UHPLC) and don’t have a method? You’ve never even seen a method for anything remotely similar. You might have even searched our HPLC chromatogram database for the application and haven’t found anything.  (After all, that’s the quickest and easiest way to get some ideas.) What to do… Let’s […]