Making the case for accurate multipoint analysis by process mass spectrometry in biological production

Accurate Multipoint Analysis by Process Mass Spectrometry in Biological Production — Summary

Importance of the topic

Accurate, continuous gas-phase monitoring is a cornerstone of robust bioprocess control. Real-time information on inlet (sparge) and outlet (effluent) gas composition enables detection of contamination, calculation of culture respiration, and timely feed or environmental adjustments. Process mass spectrometry (MS) provides multicomponent, high-precision measurements that support advanced process analytical technology (PAT) strategies and accelerate scale-up, reduce risk, and improve yield across R&D and manufacturing of biologics, vaccines, enzymes, and other fermentation-derived products.

Objectives and overview of the application note

This application note argues for multipoint, multicomponent, high-accuracy online gas analysis using process mass spectrometers in biological production. It reviews minimum requirements for meaningful process control, highlights field-proven Thermo Scientific Prima series instruments (Prima PRO and Prima BT), and illustrates how integrated gas measurements feed advanced process control (APC) systems to deliver rapid, practical value throughout product development and scale-up.

Minimum requirements for effective control

Key operational and analytical requirements identified are:

• Simultaneous measurement of both sparge (inlet) and effluent (outlet) gases.
• Measurement of all relevant gas components (O2, CO2, N2, Ar, trace gases and volatiles) rather than only O2/CO2.
• High accuracy and precision to enable quantitative metrics such as respiration rates and gas balances.
• Automatic calibration of all measured components to maintain data integrity over time.
• Flexible analysis methods and sampling schedules to support many fermentors and sampling points.
• Operational simplicity, reliability, and local technical support for routine use in production environments.

Methodology and process integration

Process MS is applied as a multistream online analyzer connected to fermentor sample lines. Typical deployment couples gas- and liquid-phase sensors with a multistream mass spectrometer whose outputs are routed to an APC system. APC implementations commonly use hybrid control models — linear formal models combined with nonlinear neural-network components — to compute setpoints for nutrient dosing, sparge gas composition and flow, agitation, temperature, pressure, and pH.

The note emphasizes comparing sparge and effluent gas streams directly because inlet gas composition can vary (ambient influences, regenerator dryers affecting CO2 retention or release), and only a true differential measurement supports reliable contamination screening and respiration calculations. Sample lines are noted to often originate in non-sterile piping regions, so system design must preserve sterility where required and account for potential contamination pathways.

Used instrumentation

The application note documents field use of Thermo Scientific process mass spectrometers dating from the early 1980s and highlights two models:

• Prima PRO — a multistream analyzer capable of monitoring 60+ fermentors without compromising sterility, designed for large-scale or multi-bioreactor installations.
• Prima BT — a bench-top configuration aimed at smaller-scale operations, offering 15 sample and 6 calibration ports for flexible deployment.

These instruments are described as magnetic-sector type mass spectrometers offering high analytical precision and the capability for automated calibration and multicomponent quantification. The note also references magnetic sector analytical performance data showing excellent repeatability and low standard deviations for atmospheric gas components measured over multiple days.

Main results and discussion

The application note conveys practical results rather than a formal experimental dataset. Representative performance summarized in the document shows consistent air composition measurements across several days: nitrogen ~78.08% (mol), oxygen ~20.95% (mol), argon ~0.93% (mol), and CO2 near ambient levels (~396–397 ppm) with small standard deviations, demonstrating instrument stability and reproducibility for routine monitoring.

Discussion points emphasize that single-parameter or discrete sensors (e.g., standalone O2/CO2 probes) are insufficient for robust PAT. Multicomponent MS provides the accuracy and breadth of information required for contamination prescreening, mass balance calculations, and reliable process metrics used by APC systems.

Benefits and practical applications

Key benefits and applications include:

• Early detection of contamination through direct comparison of sparge and effluent gas signatures.
• Accurate, real-time respiration and metabolic rate calculations to guide nutrient feeding and process optimization.
• Rapid value delivery during scale-up: MS integration often yields meaningful process control improvements within days of implementation.
• Support for PAT and APC workflows, enabling automated, model-based control strategies that improve yield and reduce time-to-market.
• Flexible deployment across development and manufacturing stages — from bench-top experiments to multi-reactor production floors.

Future trends and applications

Emerging directions and opportunities for process MS in bioproduction include:

• Tighter integration with machine learning and hybrid APC models to exploit high-resolution gas signatures for predictive control.
• Expansion of multistream capabilities and miniaturized platforms to monitor larger numbers of bioreactors with lower footprint and cost.
• Improved automation for calibration and validation to further reduce operator burden and increase data reliability in GMP environments.
• Broader use beyond fermentation — for cell culture, vaccine manufacturing, enzyme production, and bioremediation applications where gas-phase indicators provide actionable process insight.

Conclusion

Multipoint, multicomponent process mass spectrometry offers a proven, high-value path to improved bioprocess control. By delivering accurate comparisons of sparge and effluent gases with automated calibration and multistream sampling, process MS addresses key limitations of discrete sensors and supports advanced process control strategies that accelerate development, increase yields, and reduce operational risk. Instruments such as the Prima PRO and Prima BT illustrate practical implementations that scale from bench-top to production.

Reference

Traynor P. Making the case for accurate multipoint analysis by process mass spectrometry in biological production. Thermo Fisher Scientific Application Note; 2020.