Waters Acquity QDa Mass Detector

What you are buying

A refurbished and warrantied Waters Acquity QDa Detector, with remote pump controller, source vent valve and waste container, and original OEM vacuum pump. This single-quadrupole mass detector confirms compounds by mass alongside the chromatographic peak, dropping into a compatible Waters HPLC stack in roughly the footprint of a PDA detector.

Every unit we sell moves through the GenTech Certified process. Solution Scientists disassemble and inspect each module, replace all consumables and degraded wear components, then tune and calibrate the instrument and verify performance against OEM and published benchmarks using known reference chemicals. The instrument ships with its verification report. A certified-refurbished system gives you that performance without the capital cost or the lead time of a new purchase.

What Waters says about this module

Waters engineered the ACQUITY QDa to bring the analytical confidence of mass detection to the masses. Purposefully built for analytical scientists who require mass spectral data but want to bypass the steep learning curve of advanced mass spectrometry, Waters highlights this module as having true “on/off” simplicity. It integrates seamlessly into an existing optical detector stack—such as a PDA, TUV, or FLR—utilizing the same Waters Empower Software workflow. By eliminating sample-specific optimizations and manual calibrations, it provides definitive compound verification and trace impurity detection right at the chemist’s bench.

The QDa Detector runs a ZSpray dual-orthogonal electrospray ionization interface with automated gas and heating control, a disposable sample aperture, and declustering cone gas. Dual off-axis ion guides, a conjoined stacked ring ion guide paired with a second-stage quadrupole ion guide, cut neutral noise and improve ion transmission ahead of a single high-resolution quadrupole analyzer. A pre-filter ahead of the analyzer maximizes resolution and transmission while keeping the analyzer itself free of contamination. A low-noise, off-axis photomultiplier detector reaches a digital dynamic range up to 4 x 10 to the sixth. Mass range covers 30 to 1,250 m/z, with scan speeds up to 10 Hz from 100 to 1,000 m/z and 20 Hz from 50 to 500 m/z. Mass accuracy holds better than 0.2 Da across the full range, with drift under 0.1 Da over 24 hours. Ion polarity switches in 25 milliseconds. SIR acquisition runs up to 100 Hz across as many as 1,024 channels, rated at a signal-to-noise ratio above 2,000 to 1 for 100 picograms of sulfadimethoxine in positive electrospray. The detector integrates with Acquity UPLC, Acquity UPC2, Alliance HPLC, and purification LC or SFC systems, controlled through Empower 2/3 or MassLynx 4.1.

What this module does

Single-quadrupole mass detection

The ACQUITY QDa operates as a ultra-compact, single-quadrupole mass detector that acts as a powerful complement to traditional UV/Vis detectors. When connected to your HPLC or UPLC stream, it performs three vital tasks:

• Mass Confirmation: It instantly identifies peaks by their actual molecular mass (m/z), allowing you to definitively confirm compound identity and track co-eluting peaks or unexpected components that an optical detector might miss.
• Non-UV Quantitative Reach: It extends your lab’s detection limits by quantifying compounds that have poor or entirely absent UV responses, measuring trace impurities down to levels otherwise inaccessible by optical detection.
• Automatic Data Processing: Using integrated software workflows, it pairs mass spectral fragments side-by-side with chromatographic data tracks, maximizing daily laboratory output through automated mass calibration and resolution verification.

Technical detail

*OEM specifications for brand new instrument.

Labs that run this system

The Waters QDa Detector is method-compatible across the techniques most regulated and research labs run every day. These are the application areas buyers ask about most.