EQuan

• On-line clean-up of environmental samples results in improved throughput, sensitivity and RSDs
• Significant time savings over off-line sample cleanup and enrichment
• Enhanced resolution (H-SRM) for analyte specificity
• Simultaneous quantitation and structural confirmation with QED-MS/MS
• FAIMS enabled for improved detection limits

Challenges

Exposure to pesticides, antibiotics, and veterinary residues in drinking water is a significant health concern. As these chemicals become more potent, lower limits of detection (LODs) become critical. The emerging technique of choice in the environmental industry for the identification and quantitation of these residues is LC-MS/MS. However, this methodology typically requires extensive sample preparation prior to analysis, which tends to be time consuming and expensive.

Thermo Scientific Solution

With EQuan, environmental samples are directly injected for LC-MS/MS analysis, eliminating the need for off-line sample preconcentration, saving valuable time. Detection limits are improved by up to 100 times and limits of quantitation (LOQs) by up to 50 times, when compared to conventional LC-MS/MS detection using a triple quadrupole mass spectrometer.

The basis of this technology is an on-line extraction method involving column switching. The EQuan system consists of two Surveyor™ HPLC pumps with a preconcentration column (Hypersil GOLD™ 12μm, 2.1x20mm), an analytical column (Hypersil GOLD, 3μmx50mm), an autosampler, and a TSQ Quantum™ triple quadrupole mass spectrometer.

Triazine Pesticide Mix at 10 ppt,showing a comparison between conventional LC-MS/MS and EQuan. (a) shows the detection limits achieved with conventional methodology. Only two components were detected. (b) shows the same samples analyzed by EQuan. EQuan detected all components, improving detection limits by 100 times.

Limits of quantitation of Triazine pesticide mix in drinking water assayed by conventional methods vs. EQuan.

Left side shows conventional injection of six pesticides. Right side shows EQuan analysis of the same six pesticides. Example illustrates Simazine and Isoproturon at 5 ug/L by conventional method vs. 0.005 ug/L for EQuan method..

QED-MS/MS – Quantitation-Enhanced Data-Dependent™ MS/MS

This innovative scanning mode, introduced on the TSQ Quantum Access, provides simultaneous quantitation and qualification (Quan/Qual) capability for structural confirmation and quantitation, a feature with significant benefit for multi-residue screening experiments. With the ability to perform H-SRM, the MS/MS data is cleaner and less complex, making it easily searchable against an internal library for added confirmation during screening assays.

QED-MS/MS of an Herbicide Mix

SRM Quantitation (Scan Event 1) on left; MS/MS Confirmation (Scan Event 2) on right. QED-MS/MS provides simultaneous “Quan/Qual” for structural confirmation and quantitation in metabolite identification or multi-residue screens.