Archive for the ‘LC-MS/MS’ Category

Dilute, Shoot, and Elute – am I missing anything? YES!

  Everyone’s lab is different in terms of how many samples per day are processed, but they all share the common pain point of sample preparation. Some samples like blood and plasma need a significant amount of prep to remove proteins, phospholipids, and salts, whereas labs running urine or drinking water samples can “get by” […]

How do I Replace my LC Tubing?

For those that are experienced with LC, you probably have this all figured out.  If that is the case, this might serve as a good introduction to Restek products that you can use for this.  For those that are newbies to liquid chromatography, welcome and I hope you find this useful! The best way to […]

LC Columns: High-Pressure Survival of the Fittest!

As an R&D Chemist charged with developing the perfect packing method for new LC columns, one of the challenges is finding a packing method that results in a column which not only passes QC specifications but also passes our arduous lifetime analysis. During lifetime testing our columns are subjected to 1,000 continuous injections at 12,000 […]

The Clog Blog

Clogging and over pressuring are definitely problematic for Liquid Chromatography columns. Back in 2005 John Dolan’s sage advice to chromatographers to make an LC column last forever was simple, “Never open the box!” As John pointed out, this is not practical and I have to agree. But as an LC column manufacturer I have seen […]

Top 16 for 2016 – Restek LC Article Makes the Cut

If you are an avid chromatographer you likely subscribe to LC/GC magazine or its popular electronic version, E-Separation Solutions. It is definitely the place to go for news and information related to all things Chromatography. Over the years Restek has had many an article published in LC/GC and, full disclosure, we advertise there as well. Who […]

Fluorophenyl LC Phases- what you should know

They may be called PFP, PFPP, pentafluorophenyl, fluorophenyl or F5 phases. What they all have in common is the structure shown above (the pentafluorophenyl  group) attached to the silica particles. Most modern phases contain a propyl spacer between the above group and the silica, so that the phase looks something like this:     A […]

Update on Guard Cartridges for Trident Holders

        You may have seen my last blog post about guard holders and cartridges that we have available for our various LC product lines, “Which guard cartridges and holders go with which LC analytical columns?” Along those lines of discussion, the following note is available to also show what specific products are […]

What can I use as a cap for my mobile phase bottles?

Our choices for mobile phase bottle tops are based primarily on two different products. The first product is the Hub-Cap Bottle Top, catalog #26541. This is designed to fit a 4-Liter solvent bottle. :     The body (also called insert) of the Hub-Cap Top is cap is made of inert PTFE and has three […]

Pesticide analysis for cannabis flower: method and data overview

Pesticides in cannabis has been a hot topic lately and we have been getting many requests for help with this analysis. We did work on pesticide residue testing in cannabis about 6 years ago. At that time, we were limited to testing our methods with a small amount of seized material. Recently, we have been […]

Here’s to HILIC: tailor-made for the MS analysis of polar analytes and highly water-soluble species

There is much discussion these days about Hydrophilic Interaction Chromatography (HILIC) and the options it provides today’s analysts. And there should be.  It’s powerful for analysts working with polar metabolites or highly water-soluble compounds, namely when using MS/MS techniques. Since phase chemistry is Restek’s specialty, and we have designed our Raptor SPP LC column line for […]