title: Determination of halogens and sulfur in high-purity polyimide by IC after digestion by MIC.
abstract: In this work, a method for sample preparation of high-purity polyimide was proposed for halogens and sulfur determination by ion chromatography (IC) with conductivity detection and, alternatively, by inductively coupled plasma mass spectrometry (ICP-MS). A relatively high polyimide mass (600mg) was completely digested by microwave-induced combustion (MIC) using 20bar of O2 and 50mmolL(-1) NH4OH as absorbing solution. These conditions allowed final solutions with low carbon content (<10mgL(-1)) and suitable pH for analysis by both IC and ICP-MS. The accuracy was evaluated using a certified reference material of polymer for Cl, Br and S and spike recovery experiments for all analytes. No statistical difference (t-test, 95% of confidence level) was observed between the results obtained for Cl, Br and S by IC after MIC and the certified values. In addition, spike recoveries obtained for F, Cl, Br, I and S ranged from 94% to 101%. The proposed method was suitable for polyimide decomposition for further determination of halogens and sulfur by IC and by ICP-MS (Br and I only). Taking into account the lack of methods and the difficulty of bringing this material into solution, MIC can be considered as a suitable alternative for the decomposition of polyimide for routine quality control of halogens and sulfur using IC or ICP-MS.
authors.affiliation: Departamento de Química, Universidade Federal de Santa Maria, 97105-900 Santa Maria, Brazil.
authors.forename: Sindy R
authors.initials: SR
authors.lastname: Krzyzaniak
authors.affiliation: Departamento de Química, Universidade Federal de Santa Maria, 97105-900 Santa Maria, Brazil.
authors.forename: Rafael F
authors.initials: RF
authors.lastname: Santos
authors.affiliation: Departamento de Química, Universidade Federal de Santa Maria, 97105-900 Santa Maria, Brazil.
authors.forename: Flavia M
authors.initials: FM
authors.lastname: Dalla Nora
authors.affiliation: Departamento de Química, Universidade Federal de Santa Maria, 97105-900 Santa Maria, Brazil.
authors.forename: Sandra M
authors.initials: SM
authors.lastname: Cruz
authors.affiliation: Departamento de Química, Universidade Federal de Santa Maria, 97105-900 Santa Maria, Brazil.
authors.forename: Erico M M
authors.initials: EMM
authors.lastname: Flores
authors.affiliation: Departamento de Química, Universidade Federal de Santa Maria, 97105-900 Santa Maria, Brazil. Electronic address: paola.mello@ufsm.br.
authors.forename: Paola A
authors.initials: PA
authors.lastname: Mello
keywords: IC; ICP-MS; Microwave-induced combustion; Polyimide; Sample preparation