Oxalic acid standard SRM 4990C

Oxalic acid standard SRM 4990C
Name	Oxalic acid standard SRM 4990C
Cas number	144-62-7
Formula	C2H2O4
Molar mass	90.03 g/mol

Oxalic acid standard SRM 4990C is a certified reference material produced for high-accuracy analytical chemistry, used to calibrate instruments and validate methods in quantitative analysis. It is distributed as a high-purity crystalline material with characterized composition, uncertainty statements, and traceability to national measurement standards. Laboratories in metrology, pharmaceuticals, environmental monitoring, and materials science use the standard to ensure comparability of results across institutions and regulatory programs.

Overview

SRM 4990C is issued by a national metrology institute as a primary or secondary chemical standard to support measurement comparability among laboratories such as national laboratories, university research groups, and commercial testing facilities. The material serves as a benchmark in contexts that include titrimetry, gravimetry, coulometry, and chromatographic quantitation, providing a known amount-of-substance concentration for method validation and instrument calibration. Stakeholders who rely on the SRM include accreditation bodies, standards organizations, and industrial quality-control departments.

Certification and Properties

The certificate for SRM 4990C reports the certified mass fraction, associated expanded uncertainty, and the metrological basis for certification. Certification typically references calibration chains maintained by national institutes and may cite interlaboratory comparisons, primary-method determinations, and material characterization studies. Reported physico-chemical properties include purity, moisture content, melting point range, and identified impurities with quantified mass fractions. The uncertainty budget combines contributions from characterization, homogeneity, and stability assessments using established statistical protocols and international guidelines.

Preparation and Traceability

Preparation of SRM 4990C follows documented procedures for synthesis or purification, recrystallization, and packaging under controlled conditions to minimize contamination and variability. The gravimetric or coulometric determination of content is anchored to traceable mass and electrical standards held by national metrology institutes, ensuring linkage to internationally recognized units. Chain-of-custody and lot documentation support traceability to reference balances, mass standards, and measurement procedures maintained by metrology institutes and national laboratories. Stability studies under defined temperature and humidity regimes inform shelf-life and recommended storage conditions.

Applications and Use

The standard underpins quantitative determinations in analytical chemistry where oxalate or oxalic acid must be measured accurately, including calibration of titrators, validation of HPLC and IC methods, and verification of mass-balance procedures in chemical manufacturing. Regulatory testing laboratories and pharmaceutical quality-control units apply SRM 4990C when establishing method performance characteristics such as accuracy, precision, limit of detection, and linearity. Environmental monitoring programs and geochemical laboratories may use the material to verify trace-level analyses in water and soil matrices. In teaching and proficiency testing, SRM 4990C provides a known-reference point for laboratory training and interlaboratory comparison studies.

Handling, Storage, and Safety

Handling recommendations for SRM 4990C emphasize the use of appropriate personal protective equipment and engineering controls consistent with chemical safety practices at research institutions and industrial facilities. Storage instructions typically specify sealed containers, controlled temperature, and protection from humidity and contaminants to preserve material integrity. Safety data relevant to oxalic acid, as provided by chemical safety authorities, note considerations such as corrosivity, toxicity if ingested, and risks to renal function at high exposures; affected organizations implement hazard communication, exposure controls, and emergency response procedures. Disposal follows institutional hazardous-waste protocols and local regulatory requirements overseen by environmental and public-health agencies.

Quality Assurance and Interlaboratory Studies

SRM 4990C plays a central role in quality assurance programs, enabling laboratories to demonstrate measurement traceability in accreditation schemes and proficiency testing organized by standards bodies and certification organizations. Interlaboratory comparison exercises and round-robin studies that feature SRM 4990C support method harmonization and reveal systematic biases across analytical platforms. The standard is used in method validation studies reported in peer-reviewed journals, and its performance in collaborative studies informs updates to measurement standards and best-practice guidance adopted by research consortia and regulatory agencies.

Category:Chemical standards