Orthogonal array design for the optimization of closed-vessel microwave digestion parameters for the determination of trace metals in sediments

Zhou, Chao; Wong, Ming Keong; Koh, Lip Lin; Wee, Y. C.

doi:10.1016/0003-2670(95)00261-w

Cited by 43 publications

(17 citation statements)

References 16 publications

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“…Our observations regarding digestion time differ somewhat from those of Zhou, et al (1995), who suggested that changes in microwave digestion time should not affect recoveries. The authors do not imply that the digestion time has no effect on the sample decomposition; they simply indicate that 15 min is sufficient to complete the digestion of most samples and that varying the digestion times should not have statistical significance.…”

Section: Table VIcontrasting

confidence: 98%

Analysis of Environmental Samples Using Microwave-Assisted Acid Digestion and Inductively Coupled Plasma Mass Spectrometry: Maximizing Total Element Recoveries

Hassan

Rasmussen

Da̧bek-Złotorzyńska

et al. 2006

Water Air Soil Pollut

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For the routine determination of metals in environmental samples, we require microwave-assisted digestion methods that yield 'total' or 'near-total' recoveries while avoiding the use of HF acid. As inductively coupled plasma mass spectrometry (ICP-MS) is the method of detection, it is desirable to minimize the use of HCl to avoid spectral interferences caused by high Cl -concentrations. Using certified reference materials, we performed a series of modifications to the US EPA method 3051 which included: increasing the temperature and durations of microwave digestion, varying the ratio of sample mass to acid volume, and alterations to the compositions of the acid digestion mixture. The experiments were conducted using urban particulate matter (NIST-1648), coal fly ash (NBS-1633) and six CANMET certified reference materials (Till-2, Till-3, Till-4, LKSD-1, LKSD-2 and LKSD-4), in two laboratories (Health Canada and Environment Canada) using different microwave digestion systems and different ICP-MS instruments. Our modified microwaveassisted nitric acid digestion method improved recoveries for Pb, Zn, V, Fe and Cu approaching 'total' recoveries in the same matrices determined using Xray fluorescence (XRF) and instrumental neutron activation analysis (INAA) as reported in the certificates of analysis. Recoveries for other elements such as Cr and Ni compared well with 'near-total' recoveries yielded by traditional (non-assisted) acid digestion methods.

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Section: Table VIcontrasting

confidence: 98%

Analysis of Environmental Samples Using Microwave-Assisted Acid Digestion and Inductively Coupled Plasma Mass Spectrometry: Maximizing Total Element Recoveries

Hassan

Rasmussen

Da̧bek-Złotorzyńska

et al. 2006

Water Air Soil Pollut

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“…Since most sediment samples contain relatively small amount of organic substances, the quick-digestion program is suitable for their digestion. 12 The maximum microwave output can reduce the digestion time, and a high-pressure setting can increase the temperature in the digestion vessel. Thirty minutes would be sufficient for the complete digestion of a soil matrix.l°,12 Hence, quick digestion with 100% power output, a pressure setting at 1035 kPa (150 psi), a temperature setting at 200°C and a time of 30 min were used in this study.…”

Section: Analytical Proceduresmentioning

confidence: 99%

“…FIA-CV-AAS has become the most widely used method for mercury determination. 12,5,6 Different complex matrices of the analytical sample require prior mineralization for most analytical methods. The two types of digestion methods which are commonly employed for determining trace metals are wet digestion and dry ashing.…”

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confidence: 99%

“…Secondly, the reaction temperature can be elevated, thus accomplishing faster and more efficient sample digestion. 12 In sediments and other soil samples, mercury exists in different forms, such as cinnabar (HgS), organomercurials and so on.13 Partially digested final solutions can give rise to matrix effects.14 Hence, complete digestion is necessary for determining the total mercury. Recently, Adeloju et al4 evaluated some wet decomposition methods for mercury determination in environmental materials by CV-AAS.…”

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confidence: 99%

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Comparison of Acid Mixtures in High-Pressure Microwave Digestion Methods for the Determination of the Total Mercury in Sediments by Cold-Vapor Atomic Absorption Spectrometry

et al. 1996

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Four closed-vessel microwave digestion methods were compared for the accurate determination of mercury in sediments by flow-injection cold-vapor atomic absorption spectrometry. The results showed that several acid mixtures (HNO3/ H2SO4, HNO3/ HC10a, HCI/ HNO3 and HCl/ HNO3/ HF) completely digested'the soil matrix for the determination of mercury. The method using aqua regia is preferred because it is time saving, less dangerous and suitable for other tracemetal analyses. The merits of pressure-feedback microwave digestion is that it simplifies soil sample digestion, and there is no loss of mercury. The digestion methods were evaluated by determining mercury in NIST SRM 1645 River Sediment, NIES CRM No. 2 Pond Sediment and NRCC BCSS-1 Marine Sediment. Recoveries of 92 -108were achieved. Good recoveries of 94 -104% were also obtained for soil and marine-sediment samples spiked with different species of mercury.

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“…All the representative combinations distribute uniformly in the research area and can greatly reflect the situation of the whole selected examined area. This method has proven to be a cost-effective optimization strategy that can obtain the optimal conditions of each parameter in a limited number of experimental trials [24][25][26][27]. Therefore, this paper discussed four main process conditions in the transesterification reaction (i.e.…”

Section: Introductionmentioning

confidence: 99%

Optimization of biodiesel production from camelina oil using orthogonal experiment

2011

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Orthogonal array design for the optimization of closed-vessel microwave digestion parameters for the determination of trace metals in sediments

Cited by 43 publications

References 16 publications

Analysis of Environmental Samples Using Microwave-Assisted Acid Digestion and Inductively Coupled Plasma Mass Spectrometry: Maximizing Total Element Recoveries

Analysis of Environmental Samples Using Microwave-Assisted Acid Digestion and Inductively Coupled Plasma Mass Spectrometry: Maximizing Total Element Recoveries

Comparison of Acid Mixtures in High-Pressure Microwave Digestion Methods for the Determination of the Total Mercury in Sediments by Cold-Vapor Atomic Absorption Spectrometry

Optimization of biodiesel production from camelina oil using orthogonal experiment

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