Quality Management for Ion Chromatography Systems

By: Jürg Wüthrich,Markus Läubli, AnalytiX Volume 8 Issue 1

Traceable and vertified standards for IQ, OQ and PQ activities

Jürg Wüthrich, Senior Scientist R&D Europe, Sigma-Aldrich, Switzerland juerg.wuethrich@sial.com
Markus Läubli, Manager Marketing Support IC, Metrohm AG, Switzerland lae@metrohm.com

Validation and qualification processes

Today, analysts spend a great deal of time and effort ensuring that their analytical data is reliable and in compliance with specific regulations. For laboratories working in regulated environments (e.g. GMP), there are several standards that deal with the validation and qualification of processes and computer-assisted instruments. The most important guidelines are the EU-GMP Guide, DIN ISO 9001, GLP, ISO/IEC 17025, USP General Chapters <1058>, GAMP Good Practices Guide on Validation of Laboratory Computerized Systems and FDA 21CFR Part 11.

The quality of analytical data can be demonstrated by different validation and qualification tools, such as in-process quality control checks, system suitability tests and the use of validated methods. However, before the method can be validated, it is necessary to ensure that the analytical system itself is qualified (see Figure 1). In this context it is widely agreed that processes are “validated” and instruments are “qualified.”


Figure 1.The main components for good data quality 1

Figure 1.The main components for good data quality1

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Analytical Instrument Qualification (AIQ)

According to the draft of United States Pharmacopeia (USP) General Chapter <1058> “Analytical Instrument Qualification,“ instruments are qualified in a stepwise process following four phases: design qualification, installation qualification, operational qualification and performance qualification2. This is graphically depicted in Figure 2.


Figure 2.Qualification processes during the lifecycle of an analytical instrument

Figure 2.Qualification processes during the lifecycle of an analytical instrument

Design Qualification (DQ): The AIQ process timeline begins with the DQ phase at the vendor’s site where the instrument is developed, designed and produced in a validated environment (e.g. ISO 9001). The user usually does not need to repeat DQ. However, users should ensure that instruments are suitable for their intended applications and that the manufacturer has adopted a quality system for developing, manufacturing and testing. Users should also establish that the manufacturer provides installation support, service and training.

Installation Qualification (IQ): The following activities and documentation are associated with IQ to guarantee completeness and operability of the new installed system: providing detailed descriptions of the analytical system, ensuring that all components have arrived as purchased and are undamaged, verifying that the installation site meets the requirements, assembling and installing the system, and performing diagnostics and testing after installation.

Operational Qualification (OQ): OQ is performed after initial system installation, after modification of the existing system or repair of a specific module. The instrument is tested according to the manufacturer‘s specifications in the user’s environment. Therefore, the manufacturer must define test conditions and specifications. OQ can be executed by testing all individual components or the entire system.

Performance Qualification (PQ): PQ tests conclude the qualification process of a newly installed instrument and verify that the system has performance in line with its intended use. After the successful completion of PQ, the system can be handed over to the customer.

The user should perform PQ at regular intervals and not just after installation of a new instrument. The tests can be similar to those performed during the OQ phase, but the specifi cations are usually less restrictive. When PQ tests fail to meet specifi cations, the instrument requires maintenance or repair. Each laboratory should also have SOPs in place that defi ne the period of use, calibration procedures and proper maintenance.

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IQ, OQ and PQ for Metrohm ion chromatography

Metrohm AG (Herisau, Switzerland) and Sigma-Aldrich Production GmbH (Buchs, Switzerland) share a fruitful cooperation with a focus on developing customer solutions for ion analysis. While Metrohm’s emphasis is on developing and producing powerful ion chromatography systems, Sigma-Aldrich is a strong partner for the supply of chemical standards, solutions and certifi ed reference materials.

Metrohm has increased its efforts in quality management and documentation following the latest international guidelines. The recent publication “Quality Management with Metrohm – IQ/OQ for Professional IC Systems” provides detailed documentation and guidance3.

When installing a new Professional IC Instrument, the Metrohm service engineer will perform the following inspections during IQ: completeness of delivery, check of installation site and media supply, documentation of all instruments and detailed tests on hardware and software installations.

After completion of IQ, the following OQ and PQ tests are carried out: IC pump fl ow (accuracy and reproducibility), noise and drift as parameters for pump and detector stability, injector precision, injection carry-over, detector linearity, suppression, IC gradient (accuracy, reproducibility and noise of gradient steps) and temperature of the column thermostat.
parameters described above are only examples of the primary tests; Metrohm performs several other test procedures during IQ, OQ or PQ to ensure the optimum system performance.

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Qualify new and existing IC systems with IQ/OQ/PQ Kit

Chemicals, including the standards, reagents and solutions, are integral parts of testing procedures to measure the IC system’s performance. Sigma-Aldrich has developed a new IQ/OQ/PQ Kit (prod. no. 12674) that is extremely useful for qualifying ion chromatography systems. The kit is intended for testing detection linearity, injector precision and injector carry-over, and is part of Metrohm‘s “IQ/OQ Kit for IC” (6.5333.000), which includes all parts for validation of Professional IC Systems.

The kit consists of six certifi ed bromide standards (5, 10, 20, 50, 100 and 1000 mg kg-1). The calculated correlation coeffi cient for the 5 to 100 mg kg-1 standards is provided. The 50 mg kg-1 standard is used for repeatability tests (injector precision) and the maximum carry-over during injection is verifi ed with the 1000 mg kg-1 standard. The 5 to 100 mg kg-1 standards are used to prove the detector linearity. A special advantage of the kit is that the certifi ed bromide standards can be used with conductivity, UV/Vis and electrochemical detectors.

The kit’s certifi ed standards are produced in a double-accredited laboratory, fulfi lling ISO/IEC 17025 (general requirements for the competence of testing and calibration laboratories) and ISO Guide 34 (general requirements for the competence of reference material producers). Appropriate documentation is an important quality characteristic. A detailed certifi cate, showing the traceability to a NIST SRM and SI unit kg and measurement uncertainty of the certifi ed values, is included with each kit.

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  1. AAPS PharmSciTech (2004), 5 (1), article 22.
  2. Pharmacopeial Forum (2005), 31(5), 1453 – 63.
  3. 3.6.9988.503 Quality Management with Metrohm – IQ/OQ for Professional IC Systems.


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