Phenom Support Answers

A collection of questions that received good ratings and feedback from our customers.

• I am seeing a negative peak in my reversed phase chromatogram. I am using a UV detector. What is causing this?
• I am seeing extra peaks in my chromatogram, help!
• I am seeing no operating backpressure reading on my LC system. What could be happening?
• I am seeing peak fronting in my LC method, what are some causes of this?
• I am seeing peak tailing in my LC method, what are some causes of this?
• I am seeing unknown high molecular weight peaks in my LC-MS data, what could be causing this?
• I am seeing variability of results in my current SEC method, what should I do?
• I am transferring a method from a 150 mm column to a 50 mm column. How should I scale my gradient?
• I am using Lux in SFC mode, how can I switch back to HPLC?
• I developed an SPE method using spiked samples. Why do I get lower recoveries in my SPE method when using real samples?
• I filter & then dilute my samples prior to analysis, but I still see pressure problems, do you have any suggestions?
• I have a 50 mm ID Axia column, what product should I use to guard it?
• I have a leak at my detector, what are some things to check?
• I have a leak in the injector when performing a manual injection, any suggestions?
• I have decided to try the Aeris Widepore Xb-C8 and have some questions. One is as far as the 2.1 x 250 or 4.6 x 250 what kind of flow rate would you probably need for these?
• I have REALLY low backpressure on my column.
• I heard that conducting an SPE extraction with an orthogonal approach compared to my HPLC methodology would be more effective – what does this mean, and how would I go about doing it?
• I need to avoid contact of my sample with potential sources of plasticizers when using a vacuum manifold, is there a way I can achieve this?
• I need to filter my buffered mobile phase prior to use, do you have any suitable products?
• I need to work with headspace at high temperature, what seals are appropriate to use?
• I sporadically see extra peaks in my samples when using Phenex filters. What is causing this?
• I think that my elution solvent may be leaching something from my SPE device, what can I do?
• I use normal phase chromatography. Which filter do you recommend?
• I want to analyze cysteine using EZ:faast; can use performic acid to oxidize and detect cysteic acid?
• I want to use my reversed phase column in SFC mode, how should I switch it?
• If my sample has non-volatile components, can I still use a liquid injection?
• In sugars analysis from food, will the roQ dSPE kits retain sugars in the sample?
• In the dispersive SPE step of the QuEChERS method, what are the AOAC guidelines for adding magnesium sulfate and SPE sorbents?
• In the extraction step of the QuEChERS method, what are the AOAC guidelines for adding extraction salts, and solvent?
• In the Phree method, what is the role of formic acid?