BlindReferenzproben

BlindReferenzproben are sample materials used in quality assurance to assess analytical performance without revealing the true results to the tester. In a typical setup, the sample is prepared with a known level of the analyte or a defined composition, but the value is masked from the laboratory performing the test. The goal is to simulate routine samples while measuring accuracy and precision in an unbiased way.

Usage and procedures: They are a core component of external quality assessment or proficiency testing schemes. Laboratories analyze blinded samples alongside routine analyses. Results are submitted to an organizing body which compares them to target values and to peer performance, using metrics such as z-scores, percent bias, or consensus means. The blinding preserves objectivity and allows detection of systematic errors, drift, or inter-lab variation.

Creation and types: Blind reference samples may be prepared in-house or supplied by external providers. They can be blank, spiked, or composed of reference materials embedded in a matrix that matches routine samples. Blinding is ensured by masking the sample identity or by encrypting the target result. Matrices are often matched to real-world samples to preserve matrix effects.

Context and standards: They are widely used in clinical chemistry, toxicology, environmental and food testing, microbiology, and forensic analysis. Proficiency testing programs are typically governed by ISO 17043; laboratories seeking accreditation to ISO 17025 rely on such programs. Reference materials and their producers adhere to ISO 17034 and related guidelines.

Advantages and challenges: Blind reference samples provide objective assessment, benchmarking, and ongoing quality assurance. They require careful design to ensure stability, traceability, and proper blinding; costs and logistical complexity can be significant, and mislabeling or incomplete documentation may compromise results.