ChemTron RFOZNO Series Reference Electrolyte Solutions and Calibration Standards

Overview

The ChemTron RFOZNO Series comprises high-purity, NIST-traceable reference electrolyte solutions and certified calibration standards engineered for precision electrochemical measurement in laboratory, industrial QC, and regulatory-compliant environments. Designed specifically for use with pH, ORP, conductivity, and dissolved oxygen electrodes, these solutions provide thermodynamically stable liquid junction potentials and reproducible reference potentials critical to accurate sensor calibration and long-term electrode stability. The RFOZNO formulation delivers a saturated 4 M KCl electrolyte without silver/silver chloride (Ag/AgCl), eliminating risk of Ag⁺ contamination in chloride-sensitive applications—such as protein analysis, pharmaceutical buffer preparation, or wastewater testing where trace metal interference must be avoided. All pH standard solutions (pH 4.01, 6.86, 7.00, 9.18, and 10.01) are prepared in accordance with ISO 17025-accredited procedures and certified against primary NIST SRM 186, 189, and 192a; each batch includes a Certificate of Analysis documenting measured pH (±0.002 at 25 °C), uncertainty budget, and temperature coefficient (d(pH)/dT). Conductivity standards (84 µS/cm, 1413 µS/cm, 12.88 mS/cm, and 15.0 mS/cm) are formulated using ultra-pure KCl (≥99.999%) and doubly distilled water meeting ISO 3696 Grade 2 specifications, with certified conductivity values traceable to NIST SRM 3109a.

Key Features

• Ag/AgCl-free 4 M KCl reference electrolyte (RFOZNO) ensures compatibility with Ag-sensitive matrices and eliminates galvanic drift in low-chloride or protein-rich samples.
• Full portfolio of pH calibration standards spanning pH 4.01 to 10.01, each supplied in dual volumes (125 mL and 500 mL) with individual CoA referencing NIST traceability and temperature-compensated values.
• Dissolved oxygen standard (DOGALSO) formulated as air-saturated ultrapure water with defined O₂ saturation level per ISO 5814:2012, enabling verification of Clark-type and optical DO probe accuracy.
• Conductivity standards covering four decades (84 µS/cm to 15.0 mS/cm), validated across 5–35 °C using calibrated AC conductance bridges compliant with ASTM D1125 and IEC 60746-3.
• pH/ORP storage (CSHOST) and cleaning solutions (CSHOCL, CSHOPC) optimized for electrode hydration integrity and removal of organic fouling—CSHOCL contains mild surfactants and chelating agents; CSHOPC is enzymatically enhanced for protein residue dissolution.
• All solutions packaged in amber borosilicate glass with inert PTFE/HDPE septum caps to prevent CO₂ ingress, evaporation, and UV-induced degradation.

Sample Compatibility & Compliance

These standards are validated for use with all major pH, ORP, conductivity, and dissolved oxygen instrumentation—including benchtop meters (e.g., Mettler Toledo SevenCompact, Thermo Scientific Orion Star), portable field analyzers (Hach HQ40d, YSI ProDSS), and inline process sensors (Endress+Hauser Liquiline CM44P, Emerson Rosemount 5081). Each lot undergoes rigorous quality control per ISO/IEC 17025 requirements, including pH homogeneity testing (≤0.001 pH unit variation across bottle), conductivity repeatability (RSD < 0.15%), and microbial limits (<1 CFU/mL). Documentation supports FDA 21 CFR Part 11 compliance when integrated into validated LIMS or ELN workflows; CoAs include electronic signatures, audit trails, and batch-specific uncertainty statements. The absence of Ag/AgCl in RFOZNO aligns with USP and guidelines for sterile compounding and hazardous drug handling environments.

Software & Data Management

While the RFOZNO series itself is a consumable product, ChemTron provides digital integration support via downloadable .csv and .pdf CoA files linked to unique batch numbers. These files are compatible with laboratory information management systems (LIMS) and electronic lab notebooks (ELN) such as LabWare LIMS, Benchling, and Veeva Vault. Each CoA includes machine-readable QR codes for rapid traceability scanning, expiration alerts, and automated inventory reconciliation. For regulated users, ChemTron offers optional IQ/OQ documentation packages aligned with GxP expectations—including installation qualification checklists for storage conditions and operational qualification protocols for verification of solution performance on user-specific instruments.

Applications

• Calibration and verification of pH and ORP electrodes in environmental monitoring (EPA Method 150.1, ISO 10523), food safety testing (AOAC 973.41), and biopharmaceutical upstream processing.
• Validation of conductivity sensors in purified water (PW) and water-for-injection (WFI) systems per USP and EU Annex 1.
• Performance checks of dissolved oxygen probes in activated sludge reactors, fermentation bioreactors, and aquaculture systems per APHA Standard Methods 4500-O G.
• Electrode conditioning and recovery in clinical chemistry analyzers and point-of-care devices requiring frequent recalibration cycles.
• Reference material for interlaboratory comparison studies under ILAC P14 and ISO/IEC 17043 proficiency testing schemes.

FAQ

What is the difference between RFOZNO and RFOZAG reference electrolytes?

RFOZNO contains 4 M KCl without Ag/AgCl, making it suitable for chloride-sensitive or Ag-contamination–restricted applications. RFOZAG includes Ag/AgCl for higher potential stability in general-purpose use.
Are pH standard solutions certified for ISO 17025 accreditation?

Yes—each batch carries a NIST-traceable Certificate of Analysis issued by an ISO/IEC 17025-accredited calibration laboratory, including expanded uncertainty at k=2.
Can DOGALSO solution be used for optical DO sensor calibration?

Yes—DOGALSO is formulated to match the oxygen solubility profile of air-saturated water at 25 °C per ISO 5814:2012 and is validated for both electrochemical and luminescence-based DO probes.
How should opened bottles be stored to maintain accuracy?

Store upright at 15–25 °C, protect from direct light and ambient CO₂; use within 6 months. Avoid repeated temperature cycling or exposure to humid environments.
Do conductivity standards require temperature correction during use?

Yes—certified values are reported at 25 °C. Use built-in temperature compensation on your meter or apply ASTM D1125 correction factors for measurements at other temperatures.