Proficiency Testing Standards

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Proficiency testing (PT) or interlaboratory comparison testing is a critical tool not only for ISO/IEC 17025 laboratories, but also for quality assurance and continuous improvement as it allows laboratories to validate their analytical performance of specific tests, measurements, or calibrations. All participants and new users of our PT program, please visit our PT portal to register, enter data, download reporting packets, or access final results.

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Air PT

We offer air proficiency testing material in form of samples of ammonia, fluoride, hydrogen halides/halogens, lead, mercury, metals, NO, SO2, H2SO4, and particulate matter in impinger solution as a concentrate to be diluted with reagent grade water for immediate analysis. Additionally, we also provide air PT samples such as volatiles and ketones on the sorbent, semi-volatiles on PUF, PAHs on PUF, PCBs on PUF, anions, chromium (VI), lead, mercury, metals, and particulate matter on a filter paper.


Discharge Monitoring Report–Quality Assurance (DMR-QA) ensures data reliability by analyzing wastewater samples to evaluate laboratory performance.


Microbiological PT samples are placed in vials containing a Vitroid™ disk, a small disk that consists of viable microorganisms with a certified number (ISO/IEC 17025), of colony forming units (CFUs). The discs contain bacteria or fungi in a solid water-soluble matrix, that rehydrates easily. The samples in the vials are dehydrated standards to provide prolonged stability.


For the chemical analysis of pharmaceutical materials, we offer PT materials for spectroscopy studies. Further, we also provide samples for conductivity, heavy metals, loss on drying, melting range, microbial enumeration test, pH, residual solvents, residue on ignition, sterility, titration, total organic carbon (TOC), and water determination.

Solids/soil hazardous waste

To ensure reliable solid and soil monitoring, our dried soil/solid standards meet PT requirements. We provide organic PT material such as BNAs, BTEX/MTBE, diesel, dioxin and furans, gasoline, herbicides, nitrosamines/nitroaromatics, oil and grease, PAHs, PCBs, phenolics, total petroleum hydrocarbons (TPH) and metals in soil, dioxins and furans in tissue, free liquids in paint, PBDE/PCBs in sediment, PCB congeners in fish tissue, and toxicity characteristic leaching procedure (TCLP) semi-VOAs. In addition, our inorganics PT include anions, Cr (IV), cyanide, nutrients, solids and sulfide in the soil matrix, metals in sewage sludge, lead in powdered paint, specific gravity, the heat of combustion, flash point and corrosivity.

Water pollution/wastewater

Standards with high-concentrate analytes are available for water pollution and wastewater analysis. Our water pollution/wastewater PT materials include inorganic, organic, and microbiological samples. We also offer samples, such as nutrients, minerals, oils and grease, silica, trace metals, and total suspended solids (TSS), to be tested in seawater.

Water supply/drinking water

For quality testing of safe drinking water, our PT samples provide low-concentrate analytes to represent the levels observed in drinking water.

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