Determination of magnesium by thermospray flame furnace atomic absorption spectrometry (TS-FFAAS): Influence of the solvent on the analytical sensitivity.

S.G. LANAS; EZEQUIEL MORZÁN; ORNELA PIANO; JORGE STRIPEIKIS; MABEL B. TUDINO

Foz do Iguazu

Simposio; 12th Rio Symposium on Atomic Spectrometry; 2012

CENA-Universidad de San Pablo

The more rccent literature dedicated to analytical determinations by thermospray flamefimace atomic spectrometry (TS-FFAAS) [1], ha^s rejectcd the abiiity oi'this techniqul for rhedcterminalion of magnesium due to its extremely lora,.sensitivity. ihis could be aicribed totwo main reasons: the tendency of magncsium to 1'orm hydroxylated compounds and the lowtcmperalule values inside the ñunace when compar.ed to the traditional flamc atomicabsorption spectromchy (FAAS). Taking into account thc influence of the solventcharacteristics (density, surface tension, volatility, etc.) on TS-FFAAS sensitivity, theanalytical signal ofmagnesium in different water soluble solvcnts was assessed. In doing this,different proporlions ofmethanol, ethanol, i-propanol, acetonih-ile and. acetonc in watcr, wcretested for magnesium detemination. It *'as observcd that an incrcment on thc ratiosolvenl,/r,'r'ater, yielded a bettcl sensitivi[y lor ali the cases undcr sturiy. A cliscussion involvingthe influence of droplets size, reduoing environment and atomization cell temperafurc on theanal¡icai signal wili be provided. Methanol was selected as the best option. under optimizedsonditions a LoD of 41 :g L'l x,as reached. ALthough lhcsc vaLues are not an improvlment inrelation to FAAS with pneumatic ncbulization, it is the fir'st time that a calibr.ation curvc 1brmagnesium is obtaincd with a 'fs systcm. Moreovcr, the absence of clogging in thethemospray production s'ould allow' the introduction of highly saline matrices, án"áu.agingthe determination of magnesium in this kind of samples without sample pre-treatment-1. Pen Wu, Yunchang Zhang, Rui Liu, Yi Lv, Xiandeng I{ou, Talanta jj:1jjg,2010