Advances in ultrasonic slurry graphite furnace atomic absorption spectrometry

Miller-Ihli, Nancy J.

doi:10.1007/bf00326337

Cited by 105 publications

(49 citation statements)

References 11 publications

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“…Impulsion of the cavitational bubbles, extreme temperatures, and pressures is generated at the center of the collapsed bubble [36][37][38]. These effects may enhance liquid-solid mass transfer and cause physicochemical change in the processed medium considerably [39,40]. Advantages and attractive features of sonochemistry led us to explore the effect of ultrasonic waves on this catalytic system.…”

Section: Resultsmentioning

confidence: 99%

Clay‐catalyzed synthesis of 5‐substituent 1‐H‐tetrazoles

Chermahini

Teimouri

Momenbeik

et al. 2010

Journal of Heterocyclic Chem

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In this study, the possibility of 5-substituted 1-H-tetrazoles synthesis using clays as catalyst was investigated. The reaction of a series of aromatic nitriles with sodium azide was catalyzed by montmorillonite K-10 or kaolin clays in water or DMF as solvent. Conventional heating or ultrasonic irradiation was used to promote reaction. The amount of nitrile to sodium azide mole ratio, amount of catalyst, reaction time, and solvent type were optimized. The versatility of this method was checked by using various nitriles, which showed reasonable yields of tetrazole formation. It was found that using nitriles with electron-withdrawing groups result in both higher yields and lower reaction times. The catalysts could be reused several times without significant loss of their catalytic activity. Compared to conventional heating, ultrasonic irradiation reduced reaction times and increased catalyst activity. The present procedure is green and offers advantages, such as shorter reaction time, simple workup, and recovery and reusability of catalyst.

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Section: Resultsmentioning

confidence: 99%

Clay‐catalyzed synthesis of 5‐substituent 1‐H‐tetrazoles

Chermahini

Teimouri

Momenbeik

et al. 2010

Journal of Heterocyclic Chem

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“…Nitric acid has been used by several authors [27][28][29] because the analytes are mobilized from the solid particles to the liquid media, which improves the precision of the method 7 , while nitrates do not interfere in the atomization paths for the metals involved. The concentrations selected, 2.0 mol L -1 for Cu, Fe and Zn and 4.0 mol L -1 for Mn, were used according to previous studies shown in Figure 1.…”

Section: Resultsmentioning

confidence: 99%

Direct analysis of Antarctic krill by slurry sampling: determination of copper, iron, manganese and zinc by flame atomic absorption spectrometry

Alves¹,

Smichowski²,

Farías³

et al. 2000

J. Braz. Chem. Soc.

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A técnica de amostragem de suspensão aliada à espectrometria de absorção atômica com chama foi empregada para a determinação direta de Cu, Fe, Mn e Zn em matrizes de Krill antártico. O efeito dos parâmetros instrumentais e o preparo das suspensões foram estudados em função do sinal analítico. Para a determinação de Cu, Fe e Zn, as amostras foram suspensas em uma solução de HNO 3 2,0 mol L -1 e para a determinação de Mn, o krill foi suspenso em uma solução de HNO 3 4,0 mol L -1 . A precisão entre as replicas foi melhor que 5 %. A metodologia foi aplicada para a determinação direta de Cu, Fe, Mn e Zn em amostras de krill antártico, usando padrões aquosos no preparo das curvas analíticas. Os resultados obtidos estão concordantes com os encontrados na determinação por FAAS e ICP-AES, depois da digestão das amostras em um forno de microondas. Os limites de detecção foram 4,5; 1,0; 4,9 e 8,4 µg L -1 para Cu, Zn, Mn e Fe, respectivamente.Slurry sampling in combination with flame atomic absorption spectrometry was employed for the direct determination of four essential trace elements, namely Cu, Fe, Mn and Zn in Antarctic krill. The effect of instrumental operating conditions and slurry sampling preparation on the analytical signal was investigated. For the determination of Cu, Fe and Zn, samples were suspended in a solution containing 2 mol L -1 HNO 3 . In the case of Mn, 4 mol L -1 HNO 3 was necessary for the preparation of the slurry. The precision between sample replicates was better than 5%. The method was applied to the direct determination of Cu, Fe, Mn and Zn in Antarctic krill samples using aqueous reference solutions to prepare the calibration curves. The results obtained were in good agreement with those achieved by FAAS and ICP-AES after microwave-assisted wet digestion of the krill samples. The detection limits were 4.5, 1.0, 4.9 and 8.4 µg L -1 for Cu, Zn, Mn and Fe, respectively.

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“…Nevertheless, incomplete atomization and poor precision occur for slurries with particle size larger than 50 μm, which have been attributed to poor sampling and slower vaporization of larger particles from the graphite furnace platform [2,[6][7][8]. Conversely, several studies reported successful determinations with particles as large as 300 μm [9][10][11]. It was pointed out that the uniformity of the particle size was more influential on the precision, which was better for coarse particles (e.g., 250-600 μm) than for particles smaller than 250 μm [9].…”

Section: Introductionmentioning

confidence: 99%

“…Precision degrades with highly diluted and concentrated slurries due to the variations in sampling and delivery of representative aliquots onto the furnace. For stabilization of slurries, a number of viscous reagents, such as Triton X-100 [9,13,14], glycerol [20,21] and hexametaphosphate [22] have been used, while homogeneity is usually achieved by means ultrasonic agitation [4,9,10,14], magnetic stirring [12,13,15] and vortex mixing [23,24]. Among these procedures, ultrasonic agitation has been highly popular as it improves the extraction of the analyte of interest into the liquid phase, especially when slurries are prepared in acidic medium [2][3][4][5][6].…”

Section: Introductionmentioning

confidence: 99%

Slurry sampling for determination of lead in marine plankton by electrothermal atomic absorption spectrometry

Arslan

Tyson

2007

Microchemical Journal

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A slurry sampling method has been developed for the determination of Pb in marine plankton by ETAAS using a freshwater plankton certified reference material (CRM 414). Slurries were prepared in 1-3% m/v range with 1% v/v HNO 3 by ultrasonic agitation for 5 min. The effects of several chemical modifiers, including Ir(NO 3 ) 2 , Mg(NO 3 ) 2 , Pd(NO 3 ) 2 , Pd(NO 3 ) 2 +Mg(NO 3 ) 2 , and Mg(NO 3 ) 2 +NH 4 H 2 PO 4 , were investigated for the stabilization of Pb during thermal pretreatment. Lead in slurries was effectively stabilized up to 1000 °C with Ir, Pd and Pd +Mg modifiers among which Pd +Mg provided the best results with complete atomization at 1850 °C. Firings in the presence of Ir were, problematic due to ash formation inside the atomizer. Water, dilute HNO 3 and HF were examined as suspension medium. Dilute HNO 3 (1-2% v/v) proved to be advantageous over water as it afforded extraction of Pb from plankton almost quantitatively in 5 min agitation. Hydrofluoric acid was the least suitable medium. Increasing HF concentration up to 5% v/v resulted in inaccuracy and substantial background absorption. Fast-heating furnace method provided comparable accuracy and precision to that of conventional-heating in slurries of CRM 414. Detection limits and characteristic masses were, respectively, 0.49 μgL − 1 and 32 pg for the conventional method and 0.62 μgL − 1 and 37 pg for the fast-heating method. However, fast-heating approach suffered from distorted peaks at high temperatures and incomplete pyrolysis of matrix at lower temperatures. Analysis of marine plankton samples for Pb was performed by using the conventional furnace program. The results showed a high correlation with those obtained by solution ICP-MS. Differences were statistically insignificant within 95% confidence interval.

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Advances in ultrasonic slurry graphite furnace atomic absorption spectrometry

Cited by 105 publications

References 11 publications

Clay‐catalyzed synthesis of 5‐substituent 1‐H‐tetrazoles

Clay‐catalyzed synthesis of 5‐substituent 1‐H‐tetrazoles

Direct analysis of Antarctic krill by slurry sampling: determination of copper, iron, manganese and zinc by flame atomic absorption spectrometry

Slurry sampling for determination of lead in marine plankton by electrothermal atomic absorption spectrometry

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