Agilent: We broke industry habit with redesigned ion source

The electron ionization (EI) source enables attogram detection limits, a first for any EI GC/MS/MS system.

The firm said it broke its habitual design of an electron beam that was orthogonal to the ion beam into the MS quadrupole analyser.

In the new design, it was able to increase the pathlength of the electron beam and enhance ionization efficiency. More ions means more sensitivity and lower detection limits.

Lower limits – more confidence​

Dr Terry Sheehan, Agilent’s GC/MS marketing director, said lower detection limits give higher confidence in the purity of things such as food commodities and water.

“Consumers may not want to pay the higher prices for “organic” fruits and veggies, but they want to be assured that the pesticide residues are approaching “next to nothing”,” ​he told FoodQualityNews.com.

“On the more realistic side of “next to nothing”, we are now able to measure levels of residual pesticides that are below a level that can be accurately correlated with any health risk. ​

“In other words, there may be a small residue of some pesticide, but we cannot prove that this is dangerous to consumer health. ​

“To drop the detection limits further (from picograms to attograms) has diminished returns for most products. An notable exception would be baby food and infant formula.”​

The system was unveiled earlier this year and recently shown at the Korean Society for Mass Spectrometry (KSMS) 2014.

Sensitivity bonus​

Improved sensitivity offers increased confidence in results at all measurement levels, and provides the opportunity for streamlining of sample preparation procedures to save time and money.

The EI source creates more than 20 times as many ions as the current generation of EI sources, which translates to greater efficiency in the laboratory.

Much better lower limits of quantitation (LLOQ) can be achieved, up to a lower order of magnitude in many cases.

The firm said if lower detection limits are not needed yet, more precise qualifier ion ratios provide greater confidence in quantitative and qualitative results.

Sheehan said the design increased ion count by a factor of 20X to 30X.

“Over the last three decades, there have been numerous design enhancements that have led to enhancement of 2X or 3X, but 20X-30X has never been claimed​,” he said.