Merck, 1146750001, CombiCheck 20

General description
This Spectroquant® CombiCheck 20 is a high-quality laboratory solution used for internal quality control and method-controlling purposes.

These Spectroquant® standard solutions perfectly complement our ready-to-use test kits and photometers within the Spectroquant® portfolio and are ideal for validating international norm methods described in e.g., ISO, EN, APHA, and EPA.

Please visit the Reference Material Quality Grade website to find a comprehensive overview of our different grades of standards.
Application
CombiCheck 20 can be used to check the photometric measurement system (reagents, measurement device, handling) and the mode of working.
Features and Benefits
Manufactured and tested in DIN EN ISO 9001:2008 accredited laboratory
The solution is pre-diluted to a concentration that falls into the range of our Spectroquant® test kits. This eliminates the need for dilution prior to analysis and hence avoids a common source of error
Ready-to-use diluted reference materials (RMs) along with expanded measurement uncertainty ensure absolute precision
Accompanied with a certificate of analysis (COA) detailing the certified values, including uncertainty and expiry date
Directly traceable to standard reference materials (SRM) from the National Institute of Standards and Technology (NIST) or to United States Pharmacopeia (USP)
Reliable and reproducible results

Analysis Note
Standard Solution Reagent R-1:

Ammonium: 12.0 ± 1.0 mg/L NH₄-N
Chloride: 60 ± 10 mg/L Cl COD: 750 ± 75 mg/L COD
Nitrate: 9.0 ± 0.9 mg/L NO₃-N
Phosphorous: 8.0 ± 0.7 mg/L PO₄-P
Sulfate: 500 ± 75 mg/L SO₄

Addition Solution Reagent R-2 (Spike sample):

Ammonium: 8.0 ± 0.8 mg/L NH₄-N
Chloride: 40 ± 7 mg/L Cl
COD: 200 ± 40 mg/L COD
Nitrate: 7.5 ± 0.8 mg/L NO₃-N
Phosphorous: 5.0 ± 0.5 mg/L PO₄-P
Sulfate: 150 ± 30 mg/L SO₄
Legal Information
SPECTROQUANT is a registered trademark of Merck KGaA, Darmstadt, Germany