Solid phase extraction and spectrophotometric determination of mercury in tobacco and tobacco additives with 5-(p-aminobenzylidene)-thiothiorhodanine

Abstract

Foi desenvolvido um método altamente sensível, seletivo e rápido para a determinação de mercúrio, a partir da reação rápida de mercúrio(II) com 5-(p-aminobenzilideno)-tiorodanina (ABTR) e posterior extração em fase sólida do quelato colorido, utilizando discos C 18 . Em pH 3,5 e na presença do emulsificante-OP, ABTR reage com mercúrio(II) para formar um quelato vermelho na razão molar 1:2 (mercúrio:ABTR). O quelato foi enriquecido pela extração em fase sólida com discos C 18 e o quelato retido, eluído com dimethyl formamida (DMF). Um fator de enriquecimento na ordem de 50 foi obtido. Em DMF, a absortividade molar do quelato é 1,21×10 5 L mol -1 cm -1 a 545 nm, e a lei de Beer é obedecida no intervalo 0,01~3 μg mL -1 na solução medida. O desvio padrão relativo para onze replicatas a 0,01 μg mL -1 é 1,7%. Este método foi aplicado para a determinação de mercúrio em tabaco e aditivos de tabaco. Bom coeficiente de preconcentração foi encontrado, comparando-se o método proposto com outros similares.A highly sensitive, selective and rapid method for the determination of mercury based on the rapid reaction of mercury(II) with 5-(p-aminobenzylidene)-thiorhodanine (ABTR) and the solid phase extraction of the colored chelate with C 18 disks has been developed. At pH 3.5 and in the presence of emulsifier-OP medium, ABTR reacts with mercury(II) to form a red chelate of a 1:2 (mercury to ABTR) molar ratio. This chelate was enriched by solid phase extraction with C 18 disks and the retained chelate eluted form the disks with dimethyl formamide (DMF). An enrichment factor of 50 was achieved. In the DMF medium, the molar absorptivity of the chelate is 1.21×10 5 L mol -1 cm -1 at 545 nm, and Beer's law is obeyed in the 0.01~3 μg mL -1 range in the measured solution. The relative standard deviation for eleven sample replicate measurements at the 0.01 μg mL -1 level is 1.7%. This method was applied to the determination of mercury in tobacco and tobacco additives and good preconcentration was found between proposed and comparative methods results.

Selective and Sensitive Electrochemical Determination of Trace Amounts of Mercury Ion in Some Real Samples Using an Ion Imprinted Polymer Nano-Modifier

“…The samples were purchased from a local market in Hamedan, and pretreated according to previously reported procedures. [62][63][64][65][66] CV results are shown in Fig. 1a.…”

An efficient ionic liquid-based cloud point extraction to preconcentrate mercury in environmental samples and hair of occupational workers before spectrophotometric detection

“…Therefore, rapid, environmentally acceptable, validated approaches for separation of Hg(II) in environmental and biological samples in occupational environments are required. Different preconcentration-separation techniques have been utilized to preconcentrate Hg(II) ions in various samples such as solid phase extraction [1,3,6,[16][17][18], liquid-phase microextraction (LPME) [4,5,11,[19][20][21][22][23] and cloud point extraction (CPE) [24][25][26][27][28][29][30].…”

Mercury(II) determination in commercial cosmetics and local Thai traditional medicines by flow injection spectrophotometry

“…Besides, visible spectrophotometric detection is much more viable as a useful technique to develop a portable, online or at‐line system . Many spectrophotometric methods can be found in the literature for mercury determination using complexing agents such as 4‐(2‐pyridylazo)‐resorcinol , 1,3‐di‐(4‐nitrodiazoamino)‐benzene , o ‐carboxy phenyl diazoamino p ‐asobenzene , potassium iodide , 2‐mercaptobenzothiazole (MBT) and 5‐(p‐aminobenzylidene)‐thaioyhiorhodamine . The above‐mentioned spectrophotometric methods for mercury(II) determination are based on batch‐wise methods which are time‐consuming and rather large amounts of hazardous and/or expensive reagents or solvent.…”