8 LC/MS/MS Design Advancements That Improve Workflow

LC/MS/MS is perhaps one of the most common bioanalytical methods used today, offering ultrasensitive detection in the several parts per million, and sometimes billion, range. The unique specificity of tandem mass spectrometry provides greater flexibility for LC separations, expanding the applications that can utilize LC/MS/MS. It is used in a variety of applications including environment monitoring, food processing, pharmaceutical, agrochemical, biotech, toxicology, and cosmetic industries.

Taking a closer look at LC/MS/MS allows one to discover how this innovative method works and how key innovations in its design are set to change the landscape by simplifying workflows and driving more accurate results.

The utilization of liquid chromatography (LC) in tandem to multiple quadrupole mass spectrometers (MS) generates an optimized analytical testing methodology, referred to as LC/MS/MS. The LC/MS/MS method first relies on LC to separate and concentrate sample components prior to reaching the MS. After chromatographic separation, samples are introduced into the mass spectrometer where they are vaporized and ionized. Within the mass spectrometer, the ion source ionizes analyte molecules, then the first quadrupole separates the ions by their mass-to-charge ration. The second quadrupole is where ion fragmentation occurs, and the third quadrupole selectively isolates the ions for measurement via the detector.

Next generation LC/MS/MS systems are incorporating key design innovations that enhance sensitivity and throughput.

8 Design Innovations to Consider When Evaluating an LC/MS/MS System 

1. Flow-Based Technology

Flow-based technology enhances the LC/MS/MS system by utilizing hot gas for efficient desolation and preventing ions from colliding with the side walls, minimizing cleaning needs and enhancing sensitivity. In LC/MS/MS systems such the PerkinElmer QSight^® Triple Quadrupole Systems, ions are transferred from the HSID interface to the system’s Laminar Flow Ion Guide^™, then moved to the analyzing region by a flow of background gas. Therefore, no axial electrical fields are necessary, and the operator does not have to worry about field fluctuations. Additionally, instrument drift and frequent reoptimization and maintenance are eliminated for enhanced productivity.

2. Coaxial Flow Electrospray Design

Coaxial flow electrospray design prevents dispersion of like charge species in front of the sampling orifice, optimizing ion sampling and sensitivity. With no crossflow turbulent formation is reduced, minimizing ion fluctuation.

3. High-Performance Mass Filters

High-performance mass filters enhance resolution, selectivity, and signal-to-noise ratio without compromising sensitivity and transmission.

4. Independently Operating Ion Inlets

Independently operating ion inlets enable users to collect data in two complementary modes, maximizing the output from a single injection.

5. Triple Quad Collision Cells

The design of triple quad collision cells establishes a high electric field at entrance and low electric field at exit, generating ion movement quickly by field gradient. This promotes fast and efficient fragmentation (fast MRMs), shortening cycle time with zero crosstalk.

6. Dual-Probe Source

The dual-source configuration enhances throughput by switching between electrospray ionization (ESI) or atmospheric pressure chemical ionization (APCI) modes and enabling combination applications with the same or opposite polarities. Data can be collected in two complementary modes, maximizing the output of a single injection.

7. Self-Cleaning Interface Design

Some self-cleaning interface designs, like the StayClean™ technology found in PerkinElmer QSight LC/MS/MS instruments, are estimated to provide 15% higher uptime than conventional LC/MS/MS systems. The built-in hot-surface-induced desolvation (HSID^™) uses continuous hot gas clean uncharged species that might accumulate in the source, while charged species are entrained and desolvated. This process reduces chemical noise and provides a higher signal-to-noise ratio.

8. Enhanced Detection

A high-energy dynode is utilized to attract positive ions and have them collide with the dynode to form electrons, while negative ions are detected from pulse counting. This enables near-simultaneous detection of positive and negative ions without the need for high-voltage switching.

Innovation can be defined as the successful generation of new ideas to create unprecedented techniques, understandings, and processes. Download the brochure to learn how the PerkinElmer QSight LC-MS/MS incorporates the latest technologies.