Two solutions - a nitrite standard solution and also a 6 component multi-element standard solution.

Br 50 ppm   NO₃ 50 ppm
Cl 50 ppm   PO₄ 50 ppm
F 25 ppm   SO₄ 50 ppm
NO₂ 50 ppm

Traceable to SRM from NIST, tested in an ISO Guide 34 / ISO17025 accredited laboratory.

Supplied with certificate of analysis.