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

Br 40 ppm   NO₃ 40 ppm
Cl 40 ppm   PO₄ 40 ppm
F 20 ppm   SO₄ 40 ppm
NO₂ 40 ppm

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

Supplied with certificate of analysis.