TOC Standards

To evaluate higher TOC content in aqueous samples (25-1000 ppm), the European Community had set up the guidelines for preparation of TOC stock solutions and TOC standard solutions. Later on, numerous scientists have contacted Sigma-Aldrich and asked for TOC standards. We responded to the challenge and developed 6 thoroughly tested TOC standards, produced from an analytical grade KHP (potassium hydrogen phthalate), diluted in purified water and stabilized for your daily work!

Product List

All KHP solutions are filled in 250 or 500 ml white glass bottles, hydrolysis class 1 (Figure 1).

Measured Parameters

TOC Application test tolerances:
1000-500 ppm +/- 10 ppm
250-100 ppm +/- 5 ppm
50-25 ppm +/- 3 ppm
Assay determination by titrimetry
Shelf life: 9 months from QC release

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For low level TOC determination used to monitor the performance of various operations during the manufacture of medicines, the European Pharmacopoeia and the USP set up guidelines for the measurement of low level TOCs, (USP 23 <643> "TOC and Conductivity", PhEur Cap. 2.2.44). Both pharmacopoeias describe the procedures used to qualify the chosen method and the interpretation of results in limit tests.

Since the suitability check has to be carried out in defined, narrow time frames, the standard solution and suitability solution have to be prepared frequently. Furthermore, the preparation of reagents also requires scrupulous cleaning of glassware to remove organic matter. Finally, the continous preparation of these samples is a critical point in all system suitability measurements and means a high effort for laboratory staff.

Fluka has been innovative, met the challenge and now offers a convenient ready-to-use kit for system suitability tests. The kit (Cat. No. 95451, see Figure 2) contains 5 solutions:

• 3 x 40 ml reagent grade water
• 1 x 40 ml system suitability solution
• 1 x 40 ml standard solution

Figure 2: Assembly of TOC System Suitability Test Kit acc. USP

The solutions are stabilized and filled under laminar flow in pre-cleaned vials. These vials are equipped with open-top screw caps and specially designed septa (10 mil of Teflon facing 90 mil of silicone). The vials are made of low extractable borosilicate glass. The ampoules are tailor-made for most autosamplers. The kit is assembled in a box containing a holder for the 5 vials for safety and convenient storage (see Figure 2); it is delivered at 4°C and should be stored in a refrigerator until use.

The convenient kit reduces your sample preparation by 1-1.5 hours!

Each kit is delivered with a Certificate of Analysis.

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