White Paper

Automated Performance Verification

White Paper

Advances in UV/VIS Spectroscopy

The CertiRef module verification tool integrates automated performance verification into the analytical workflow. For USP 857 and Ph.Eur. compliant performance verification, including the new stray light test.
The CertiRef module verification tool integrates automated performance verification into the analytical workflow. For USP 857 and Ph.Eur. compliant performance verification, including the new stray light test.

Performance verification is essential to ensure accurate and reliable instrument performance. Widely accepted guidelines for performance verification of spectrophotometers are described in the US Pharmacopeia chapter, USP 857

The recommended tests include the check of photometric accuracy and repeatability, wavelength accuracy and repeatability, instrument resolution as well as stray light measurement.

The US Pharmacopeia has introduced the USP 857 chapter on ultra-violet visible spectroscopy and adapted the test for stray light. Here, we compare the methods for measuring stray light according to the current and previous version of the US Pharmacopeia, assess the advantages of the new test and introduce automated optical performance verification.

Automate your optical performance verification

With increasing demands for time-consuming performance verification in regulated laboratories, the CertiRef modules offer a fully automated USP 857 and European Pharmacopeia (Ph.Eur.) compliant solution. Performance checks can be started easily with One Click™. Once started the performance verification tests are automatically carried out using certified reference materials according to USP 857 or Ph.Eur. respectively. All certificate data are securely stored on the CertiRef module, the test results are automatically evaluated and a comprehensive report is generated. Save time and avoid errors due to manual analysis.

Download the Brochure and learn about automated optical performance verification and compliance to latest USP stray light test requirements.

Performance verification in UV/VIS Spectroscopy

Table of Contents

1. Performance verification in UV/VIS Spectroscopy

 1.1 CertiRef™ – Automated and Pharmacopoeia Compliant Performance Verification

 1.1.1 How it works in detail

 1.1.2 What are the benefits of CertiRef™?


1.2 Stray Light – A Fundamental Parameter

 1.2.1 Compliance to the Latest USP stray light regulations


1.3 Service Offering for UV/VIS Spectrophotometers

 1.3.1 Good UV/VIS Practice

 1.3.2 UV/VIS instrument qualification

 1.3.3 Routine UV/VIS operation

1.1 CertiRef™ – Automated and Pharmacopoeia Compliant Performance Verification

Regulated environments require performance verification of UV/VIS spectrophotometers on a regular basis. Instrument performance is the main factor directly affecting the accuracy and repeatability of measurements. It is therefore important that it be monitored regularly and documentary evidence is provided. As the procedure for performance verification is intricate and time consuming there are great benefits in integrating it in the analytical workflow. For this reason METTLER TOLEDO has developed an accessory, the CertiRef, for automatic calibration and performance tests of the UV/VIS Excellence spectrophotometer instrument line. The CertiRef module offers a full US Pharmacopoeia compliant solution for the automated performance verification of the UV/VIS Excellence spectrophotometers UV7, UV5 and UV5Bio.

1.1.1 How it works in detail

The quality of UV/VIS spectrophotometry measurements is quantified in its spectrum. Performance tests have to verify:

  • that the wavelength positions (x axis) are correct (wavelength accuracy) and stable (wavelength repeatability),
  • that the intensities, absorbances or transmittances (y axis) are correctly measured (photometric accuracy) and stable (photometric repeatability), and
  • that the measured shape of the spectrum is correct and not distorted (resolution toluene, stray light).

Certified reference materials (CRMs) manufactured and certified by Starna Scientific Ltd (England), are used to carry out the tests. The CRMs are contained in heat sealed, quartz cuvettes and accommodated in the CertiRef module, which protects the cuvettes against light and damage, allowing long-term use. The fully automated system runs the pharmacopoeia performance calibration tests in less than 10 minutes, displaying detailed results on the terminal screen once completed. As the results are also stored in the instrument, it is possible to call up the control charts of up to 100 past calibrations. The results of each test can be printed or stored as a PDF file.


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Automated Performance Verification
Figure 1: The sealed reference material CRM containing cuvettes of the CertiRef module. Figure 2: The CertiRef module mounted on top of a METTLER TOLEDO UV7 spectrophotometer.