A quartz crystal microbalance sensor for the determination of nitroaromatics in landfill gas

Rocha-Santos, Teresa; Gomes, M. Teresa S.R.; Duarte, Armando C.; Oliveira, João A.B.P.

doi:10.1016/s0039-9140(00)00292-7

Cited by 8 publications

(4 citation statements)

References 11 publications

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“…The effect of pH on mercury sorption in the column's reactive phase was evaluated by varying the pH in the 1 -5 range [19] with a constant injection of 600 ng L -1 of mercury solution and 3 min. sampling time.…”

Section: Effect Of Physical and Chemical Parametersmentioning

confidence: 99%

“…Mercury contamination in environmental samples is usually caused by less than 1 mg L -1 of this element, thus requiring highly sensitive techniques to determine and quantify its presence. Several analytical techniques exist to determine mercury at trace levels [7][8][9][10][11][12][13][14][15][16][17][18][19][20]. One of these techniques is cold vapor atomic absorption spectrometry (CVAAS), which is suitable due to its high sensitivity for accurate determinations of mercury [11,14,18].…”

Section: Introductionmentioning

confidence: 99%

“…One of these techniques is cold vapor atomic absorption spectrometry (CVAAS), which is suitable due to its high sensitivity for accurate determinations of mercury [11,14,18]. However, CVAAS technique's selectivity and sensitivity to environmental samples is strongly dependent on the matrix components [19]. Preconcentration steps based on amalgamation onto a gold trap have been used to enhance the sensitivity in mercury determinations by atomic absorption spectrometry [7-10, 15, 16].…”

Section: Introductionmentioning

confidence: 99%

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Determination of Hg in water by CVAAS using 2-aminothiazole modified silica

et al. 2005

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This paper discusses a rapid and sensitive method developed to determine trace levels ofmercury in natural water samples by cold vapor atomic absorption spectrometry using a preconcentrationsystem composed by mini-column packed with 100 mg of 2-aminothiazol modified silica gel (SiAT)coupled on-line with the spectrometer’s cold vapor generator system. The optimum preconcentrationconditions are also described here. The preconcentrated Hg(II) ions were eluted directly from the columnto the spectrometer’s cold vapor generator system using 100 μL of 2 mol L -1 hydrochloric acid and theretention efficiency achieved exceeded 95%. The enrichment factors determined were 29, 38 and 46using 3, 4 and 5 mL of preconcentrated aqueous solutions containing 400 ng L -1 of Hg. The detectionlimit calculated was 5 ng L -1 . The preconcentration procedure was applied to determine trace levelmercury in spiked river water samples.

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Section: Effect Of Physical and Chemical Parametersmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Determination of Hg in water by CVAAS using 2-aminothiazole modified silica

et al. 2005

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“…Teresa et al developed CuPc-coated on a quartz crystal microbalance (QCM) as a sensor material for oxidative combustion of nitroaromatics to -NO 2 in landll gas. 29 Different MPcs and their composites with oxide networks were employed as homogeneous and heterogeneous photocatalysts in the reduction of nitroaromatic compounds. 30 To the best of our knowledge, there are no reports on the chemosensing ability of differently substituted phthalocyanines to detect NACs.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and photophysical characterization of dimethylamine-derived Zn(ii)phthalocyanines: exploring their potential as selective chemosensors for trinitrophenol

et al. 2015

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We report a novel synthetic approach, with good yields, for the synthesis of selective dimethylaminesubstituted phthalonitriles (1-3) in the presence of triethyl phosphite and dimethylformamide at 160 C.The peripherally modified dimethylamine substituted Zn(II)phthalocyanines (ZnPc1-3) with varied numbers and positions of dimethylamine groups were prepared for a systematic investigation of the effect of the substituents on their electronic and spectroscopic properties. Compounds show strong aggregation behaviour in methanol and this behaviour decreases with the increase of the alkyl chain length of the alcohol solvents (i.e., from methanol to octanol). The fluorescence quantum yields of ZnPc1-3 showed an excellent correlation with the extent of the molecular aggregation. The versatility of the ZnPc1-5 compounds possessing both electron donating and electron withdrawing substituents at their periphery is investigated towards the detection of nitroaromatic compounds (NACs) in solution and in the vapour phase. It was found that ZnPc1-5 exhibit high selectivity towards trinitrophenol (TNP). A good linearity of fluorescence detection using ZnPc3 as the fluorescent probe was observed in the concentration range of 50 Â 10 À6 to 450 Â 10 À6 M in chloroform, with a detection limit (LOD) of 11 AE 2 ppm. Stern-Volmer (SV) and DFT studies reveal that the fluorescence quenching behaviour occurs through photo-induced electron transfer from the excited state of ZnPcs to TNP with static quenching behaviour occurring in a predominant fashion. The formation of a porous morphology of ZnPc3 thin films promotes high selectivity and accessibility to TNP vapours (7.7 Â 10 À3 ppb).

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