Harry Prest | Authors


Why Use Signal-To-Noise As a Measure of MS Performance When It Is Often Meaningless?

Signal-to-noise of a chromatographic peak from a single measurement has been used determine the performance of two different MS systems, but this parameter can no longer be universally applied and often fails to provide meaningful estimates of the instrument detection limits (IDL).

Reducing Matrix Impact on Trace Analysis with GC–MS: A Simple Capillary Flow Technology "Tee" for Improved Backflush Efficiency

Capillary flow technology (CFT) devices are microfluidic components that extend capillary GC capabilities through simple and robust connections between pressure/flow modules and columns. One of the most powerful and simple is the CFT Tee. This is especially useful in GC–MS analysis providing (1) rapid column and inlet maintenance without MSD venting and (2) the capability of rapidly removing late eluting interferences from the column by forcing their retreat into the injection port through "backflushing". Removing these interferences improves column and detector longevity and analytical integrity. Backflushing is very valuable for trace GC–MS analysis in samples from complex matrices like soil, foods or tissues. The CFT Tee uses pressure-pulsed injections and constant flow mode with minimal loss in the MS signal. This approach will be useful to all GC–MS users who want to improve their instrument uptime.

Recent Improvements in Benchtop GC–MS

The 30-year history of advances in gas chromatography–mass spectrometry technology continues today. Recent improvements in hardware, electronics, and data analysis software have resulted in new levels of productivity and sensitivity that have broadened the potential applications for this laboratory mainstay.

Determination of Phthalate Esters by Positive Chemical Ionization MS with Retention-Time Locked GC

The authors describe a new instrumental method for determining phthalate esters using positive chemical ionization and retention-time locking GC.