Direct comparison of OMNIS and Titrando for mixed acids and TMAH

Importance of the topic

Accurate and reproducible titration of complex mixtures is essential in industrial quality control and research, especially for applications such as aluminum etching baths and semiconductor cleaning solutions. Precise quantification of multiple acids and quaternary ammonium hydroxides directly influences process efficiency, safety, and product consistency. Automated platforms with advanced resolution and signal processing address the growing demand for reliable analytical results.

Objectives and study overview

This study presents a direct comparison between two Metrohm titration systems—the OMNIS Professional Titrator and the 888 Titrando—using identical analysis parameters. Customer-generated data from Taiwan assess performance in determining nitric acid, phosphoric acid, acetic acid in an aluminum etching bath, and tetramethylammonium hydroxide (TMAH) in aqueous samples.

Methodology and instrumentation

Analyses were conducted under confidential sample preparation protocols. Both systems employed the same titrants, stirring rates, and endpoint criteria. The OMNIS Professional Titrator featured:

• 100 000-step digital dosing resolution
• 3S Liquid Adapter for secure reagent handling
• dEcotrode Plus digital electrode for fast, low-noise signal transfer

The 888 Titrando configuration included:

• 10 000 or 20 000-step dosing resolution (depending on unit)
• Ecotrode Plus analog electrode

All measurements were repeated across multiple days to evaluate precision and reproducibility.

Main results and discussion

For aluminum etching bath samples, both systems delivered similar mean concentrations, but OMNIS demonstrated lower relative standard deviations:

• Nitric acid: OMNIS mean 4.89 % (RSD 0.37 %) vs. Titrando 4.97 % (RSD 0.28 %)
• Phosphoric acid: OMNIS mean 70.16 % (RSD 0.06 %) vs. Titrando 70.07 % (RSD 0.14 %)
• Acetic acid: OMNIS mean 9.78 % (RSD 0.70 %) vs. Titrando 9.73 % (RSD 1.56 %)

In TMAH determinations (nominal 2.380 %), OMNIS achieved mean 2.3783 % (RSD 0.023 %) compared with Titrando mean 2.3809 % (RSD 0.040 %). The superior dosing resolution and digital electrode performance of OMNIS reduced measurement noise and improved reproducibility.

Benefits and practical applications

The OMNIS platform offers multiple advantages for laboratories and industrial settings:

• Enhanced accuracy through ultra-fine dosing steps
• Improved signal stability with digital electrodes
• Secure reagent management via 3S Liquid Adapter
• Modular design supporting parallel titrations and method flexibility

These features streamline routine QC, process control for etching baths, and analytical workflows in semiconductor manufacturing.

Future trends and potential applications

Future developments in automated titration will focus on integrating real-time data analytics, predictive maintenance, and machine learning–driven method optimization. Expansion of modular, multi-parameter systems will enable simultaneous monitoring of diverse analytes in environmental, industrial, and pharmaceutical samples.

Conclusion

The comparative evaluation confirms that the OMNIS Professional Titrator meets or exceeds the performance of the established 888 Titrando system in mixed acid and TMAH analyses. Its higher dosing resolution and digital electrode technology deliver more consistent, precise, and efficient results, supporting its implementation in demanding analytical laboratories.