INVESTIGADORES
SAVIO marianela
congresos y reuniones científicas
Título:
Determination of total arsenic in potato by hydride generation-microwave induced nitrogen plasma atomic emission spectrometry (HG-MIP-OES)
Autor/es:
ALICIA MOLLO; ALEXANDRA SIXTO; FLORENCIA CORA JOFRE; JAVIER SILVA; SEBASTIÁN DINI; FACUNDO IBÁNEZ; MARIANELA SAVIO; MARIELA PISTÓN
Lugar:
mexico
Reunión:
Congreso; Colloquium Spectroscopicum Internationale XLI & I Latin American Meeting on LIBS; 2019
Resumen:
HG - AAS is a well stablished technique for arsenic (As) determination in complex matrices. Despite the advantage ofthe MIPOES that runs on air, until now, very few methods using hydride generation microwave induced plasmaemission atomic spectrometry (HG-MIPOES) were developed1. This technique proposes the use of nitrogen as theworking plasma forming gas. The aim of this work is to present the capabilities of HG-MIPOES for the determination oftotal As in potato tubers.Analytical determinations were performed at 193.695 nm on an Agilent 4210 MIPOES spectrometer equipped with astandard torch and a multimode spray chamber for hydride generation (MSIS, Agilent). The multichannel spraychamber was operated with one channel to feed the sample and the other for the reductant (NaBH4). Samples weretreated by microwave assisted digestion employing 0.5 g of potatoes samples (dried and 1 mm sieved) and 8 mL ofHNO3 1:1. The heating programme was 20 min. ramp up to 120 ºC, 20 min. at 120 ºC; 20 min. ramp from 120 ºC up to170 ºC and 15 min. at 170 ºC. After digestion, samples were diluted with ultrapure water to 25 mL. The pre-reductionstep was carried out with HCl 37% (w/v) and KI 20% (w/v) in the ratio: sample/standard (10): HCl (1): KI (1). Thereductant for the hydride generation was NaBH4 2% (w/v) in NaOH 0.5 % (w/v). Samples and reagent blanks wereanalysed in triplicate. MIPOES operating conditions were: N2 flow 0.7 L min-1; pump speed 30 rpm; viewing position10; read time 10s.Figures of merit found were: linear range assayed from 4.0 to 100 μg L-1 (Intensity = 23.14 C (μg L-1) + 12.77; R2 = 0.997),precision of repeatability (n=3) sr(%) = 3.4. Trueness was assessed using a certified reference material (NIST 1568a RiceFlour) and by a spike/recovery assay at the maximum allowed concentration set by the regional regulation (n=3)2.Recoveries were all better than 70.0%. LOD was 1.2μg L-1 (3.3s). Arsenic concentration in all the analysed samples wasbelow the LOD.HG-MIPOES was successfully applied for the screening of total as levels in potato samples to comply with currentregulations. This method is an economical alternative to HG-AAS and other techniques that use argon plasma.