Assay of Sodium Nitrite

Purification and utilization of a formerly incinerated sodium nitrite bearing wastewater stream

“…Anions in the product were determined using ion chromatography using a Dionex ICS-2000 Ion Chromatography system with an AS11 Analytical column The amount of sodium nitrite present in an aqueous sample was determined by diluting an appropriate amount of ~40 wt% material with water and adding a known excess amount of ceric ion to completely oxidize the nitrite, and then back-titrating the residual ceric ion with ferrous ion [2].…”

“…One of the steps involves the batch reaction of a sodium bisphenate (1, where R is a substituted diaryl moiety) with a 4-nitro-N-alkylphthalimide (2) in the presence of a hexaalkyliminium halide phase transfer catalyst (PTC, 3) in an aromatic organic solvent at elevated temperature, to produce bisimide 4 (Scheme 1, details of the reaction are omitted for competitive reasons), which is subsequently converted to a dianhydride, and then reacted with an aromatic diamine to produce a polyetherimide. The bisimide product (4, Scheme 1) is soluble in the solvent employed, and the sodium nitrite byproduct is insoluble in the reaction media.…”