Determination of phosphorus in biodiesel using FIA with spectrophotometric detection

Greener procedures for biodiesel quality control

“…This can be exemplied by the spectrophotometric determination of Si, P, Fe, and Al, in which the multicommuted stepwise injection analysis system allowed for less waste generation, but pre-digestion of the sample with 5 mL of 10 mol L À1 HNO 3 plus 2 mL of 9 mol L À1 H 2 O 2 was required. 114 In this sense, a greener alternative was proposed for P determination, 115 involving replacement of the wet-acid digestion in a heating block (which consumes 10 mL HNO 3 , 2 mL H 2 SO 4 and 6 mL H 2 O 2 per determination) 15 by calcination as previously proposed. 116 It requires only 500 mg MgO 2 and an equivalent amount of 1.4 mL H 2 SO 4 per determination.…”

“…11,12 As a contradiction to the objective of using greener fuels, most of these procedures are timeconsuming, expensive, and generate large amounts of wastes (usually comprising toxic chemicals and organic solvents). Titrimetric methods, 13 chromatographic separations that require previous chemical derivatisation 14 and elemental analysis aer complete sample mineralisation 15 are representative examples.…”

Biodiesel: Production, Characterization, Metallic Corrosion and Analytical Methods for Contaminants

“…A graphite-furnace AAS method was developed for the direct determination of phosphorus in biodiesel using a solid sampling accessory [164]. Simpler methodologies using spectrophotometry were developed [165,166]. In the first work biodiesel samples were mineralized (dry ashing) and their residue containing phosphate was reacted with 1-amino-2-naphthol-4-sulfonic acid to form a blue molybdenum complex [165].…”

“…In the second work biodiesel samples were digested using an acid mixture and the obtained solution containing phosphate was mixed with ammonium molybdate and potassium and antimony tartrate ion to form phosphomolybdic acid (yellow) [166]. An electroanalytical method was developed for phosphorus determination in biodiesel using a phosphomolybdic modified electrode [167].…”

Efeito do tamanho de nanotubos de carbono de paredes múltiplas em sensores eletroquímicos para moléculas de interesse farmacêutico

“…Neste sentido, as análises por injeção em fluxo (FIA-"Flow Injection Analysis") [3] ou por injeção em batelada (BIA-"Batch Injection Analysis") [4] têm sido amplamente exploradas para satisfazer estes requisitos. Os sistemas FIA e BIA permitem o acoplamento a diversos tipos de detectores, tais como espectrofotométricos [5][6][7], fluorescentes [8,9], termométrico [10], quimiluminescentes [11][12][13], potenciométricos [14][15][16], voltamétricos [17][18][19][20], amperométricos [21][22][23][24], entre outros. Os dispositivos eletroquímicos de análise oferecem vantagens tais como alta sensibilidade, ampla faixa linear e instrumentação simples e portátil (requer baixa quantidade de energia que pode ser fornecida por uma bateria) [25], e portanto, atendem a demanda por métodos analíticos modernos.…”