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Proficiency Testing (PT) and Quality Control (QC) products

Simplify Your Lab’s Path to Proficiency and Compliance

Ensure confident, compliant results with NSI Proficiency Testing (PT) and Quality Control (QC) products—designed to work seamlessly together so your lab can excel in every proficiency test.

Why Combine PT & QC?

  • Build confidence by practicing with QC materials derived from prior PT samples, complete with a certificate of analysis.
  • Improve accuracy and reliability before official testing begins.
  • Streamline audits with compliant, traceable materials designed for regulatory success.
  • Reduce cost and time with consistent, easy-to-implement testing workflows.

Our PT & QC solutions empower your laboratory to practice, refine protocols, and verify performance in advance—an “open-book” preparation approach proven to enhance overall testing precision and audit readiness.

Explore our full catalog of matched PT and QC materials designed to help your lab meet every challenge with confidence.

Download Our PT Brochure

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SKU: PEI-032

Total Phenolics (2 pack)

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  • Brand NSI
  • Raw Material >95% min; as available
  • Certification Single: Grav. w/Analytical Confirmation
SKU: PEI-031

Amenable and Total Cyanide (2 pack)

  • CCL
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  • Brand NSI
  • Concentration 0.1 - 1 mg/L
  • Raw Material >95% min; as available
  • Certification Single: Grav. w/Analytical Confirmation
SKU: PEI-029

Oil and Grease (2 pack)

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  • Brand NSI
  • Raw Material >95% min; as available
  • Certification Single: Grav. w/Analytical Confirmation
SKU: PEI-026

Demand (2 pack)

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  • Brand NSI
  • Raw Material >95% min; as available
  • Certification Single: Gravimetric w/IC Confirmation
SKU: PEI-020K

EPA WS Inorganics Kit

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  • Brand NSI
  • Raw Material >95% min; as available
  • Certification Single: Grav. w/Analytical Confirmation
SKU: PEI-018K

Full NELAC WS Inorganics Kit

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  • Brand NSI
  • Raw Material >95% min; as available
  • Certification Single: Grav. w/Analytical Confirmation
SKU: PEI-017

Inorganic Disinfection By-Products Drinking Water Inorganic Standard

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  • Brand NSI
  • Raw Material >95% min; as available
  • Certification Single: Gravimetric w/IC Confirmation
SKU: PEI-016

Trace Metals Drinking Water Inorganic Standard

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  • Brand NSI
  • Raw Material >95% min; as available
  • Certification Single: Gravimetric w/ICP Confirmation
SKU: PEI-015

Cyanide Drinking Water Inorganic Standard

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  • Brand NSI
  • Concentration 0.1 - 0.5 mg/L
  • Raw Material >95% min; as available
  • Certification Single: Grav. w/Analytical Confirmation
SKU: PEI-014

Turbidity Drinking Water Inorganic Standard

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  • Brand NSI
  • Raw Material >95% min; as available
  • Certification Single: Grav. w/Analytical Confirmation
SKU: PEI-013

TOC/DOC Drinking Water Inorganic Standard

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  • Brand NSI
  • Raw Material >95% min; as available
  • Certification Single: Grav. w/Analytical Confirmation
SKU: PEI-012

Residual Free Chlorine Drinking Water Inorganic Standard

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  • Brand NSI
  • Raw Material >95% min; as available
  • Certification Single: Grav. w/Analytical Confirmation
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