Microwave Digestion Method Research Articles

Determination of Metal Impurities in Carbon Nanotubes Sampled Using Surface Wipes.

Residual metal impurities in carbon nanotubes (CNTs) provide a means to distinguish CNT from non-CNT sources of elemental carbon in environmental samples. A practical and cost-effective analytical approach is needed to support routine surface monitoring of CNT metal tracers using wipe sampling. Wipe sampling for CNT metal tracers is considered a qualitative indicator of the presence of CNTs, not a quantitative exposure metric. In this study, two digestion approaches (microwave-assisted nitric acid/H2O2 digestion and ultrasonic nitric/HF acid digestion) in conjunction with Inductively Coupled Plasma Mass Spectrometry (ICP-MS) determination were evaluated for their ability to extract metal impurities from CNT particles captured on wipe substrates. Aliquots of different carbon nanotubes (including NIST 2483 single-wall CNT) with and without GhostWipes™ (ASTM E-1792 compliant) were used to compare the performance of the digestion methods. The microwave digestion method accommodated the bulky wipe sample and also eliminated potential ICP-MS signal interferences related to incomplete digestion. Although quantitative recoveries requiring lengthy multistep digestion protocols may be necessary in other applications, the near-total recoveries achieved in the present study for CNT catalyst elements were adequate for identifying surface contamination of CNTs in the workplace using wipe sampling.

The Levels of Trace Elements in Honey and Molasses Samples That Were Determined by ICP-OES After Microwave Digestion Method.

The aim of this study is determining the amount of Al, Cu, Fe, Mn, Ni, Pb and Zn in samples of molasses and honey which were gathered from the Sakarya and Istanbul regions. In this study, trace elements in 8 honey and 20 molasses samples with different botanic features were evaluated. The sample preparation phase was performed via wet decomposition method and microwave digestion system. The accuracy of the method was checked by the standard reference material; tea leaves (INCY-TL-1) and NIST-SRM 1515-apple. The concentrations of essential trace elements (TEs) were observed in the range of 1.61 ± 0.01-287.03 ± 1.07; 0.21 ± 0.01-11.04 ± 0.12; 0.35 ± 0.03-21.71 ± 0.02 and 1.19 ± 0.01-60.90 ± 1.09 μg g(-1) for iron, copper, manganese and zinc ions, respectively, while the toxic element contents were observed in the range of 0.82 ± 0.17-3.06 ± 0.03; 0.04 ± 0.05-1.96 ± 0.03 and 0.62 ± 0.01-120.52 ± 0.10 μg g(-1) for lead, nickel and aluminum ions, respectively. The concentrations of basic TEs iron, copper, manganese and zinc were determined as 3.87 ± 0.04-16.76 ± 0.06; 0.45 ± 0.03-2.15 ± 0.01; 0.13 ± 0.01-15.02 ± 0.14 and 0.80 ± 0.09-12.03 ± 0.19 for honey samples. Also, toxic metal, lead, nickel and aluminum values in the honey samples were determined as 1.21 ± 0.12-2.46 ± 0.21; 0.28 ± 0.14-0.88 ± 0.43 and 2.11 ± 0.02-8.04 ± 0.08. A comparison between gathered data and literature values has performed and it is determined that such findings are suitable with the literature.

Selection of wet digestion methods for metal quantification in hazardous solid wastes

Quantifying metal concentration in a hazardous solid waste is critical in evaluating techniques for metal removal or recovery from the waste. Numerous protocols have been published on the digestion of hazardous waste, with diverse methods yielding dissimilar extraction efficiencies for different metals, due to differences in composition of the wastes and chemical forms of the metals. The lack of standard methods (or failure to state the method used) has resulted in inconsistencies in data reported by different laboratories, leading to variations in metal recoveries. Using fly ash as an example, this study compares 11 metal extraction methods including ASTM, USEPA, ultrasonic-assisted and microwave digestion methods as well as a modified Tessier’s sequential extraction procedure for the extraction of metals (Al, Cd, Cr, Cu, Fe, Ni, Pb and Zn). The efficacy of acid digestion was metal dependent. ASTM method D 6357-11 was found to be an effective digestion method for most metals primarily due to the dissolution of metals bound in silicate matrices, while a microwave digestion technique (which hastened the digestion process significantly) was effective for Cd and Pb. This study highlights the importance in the selection of the most appropriate protocol for the digestion of hazardous solid waste.

Optimization and Validation of a Microwave Digestion Method for Multi-element Characterization of Vranec Wines

An analytical method for determination of multi-element composition of Vranec wines using microwave digestion for sample preparation and inductively coupled plasma mass spectrometry (ICP-MS) was optimized and validated. Best recoveries, ranging from 87 to 114 %, were obtained for all analyzed elements, using a volume of 5 mL wine and 5 mL HNO3 for sample microwave digestion. In total, 38 elements (Ag, Al, As, B, Ba, Be, Bi, Ca, Cd, Co, Cr, Cs, Cu, Fe, Ga, Ge, In, Li, Mg, Mn, Mo, Na, Ni, P, Pb, Pd, Rb, S, Sb, Se, Si, Sn, Sr, Te, Ti, Tl, V, Zn) were determined in wines. The calibration curves of all elements were linear with correlation coefficients (R 2) ranging from 0.9920 for 11B to 1.0000 for 53Cr and 88Sr. The accuracy of the method was checked with a standard addition method showing good repeatability and reproducibility (relative standard deviation, RSD <10 %). Vranec wines were fermented with Saccharomyces cerevisiae yeast strains commercial Clos, RC212, D254, and BDX, and six autochthonous Vinalco yeasts. The content of total elements in all Vranec wines ranged between 348 to 678 mg/L, observing lower amounts in wines fermented with the autochthonous Vinalco yeast. The content of harmful elements, such as Pb and Cu, was below the maximal allowed concentration in all wines.

Application of the normalization process in the survey of atmospheric deposition of heavy metals in Albania through moss biomonitoring

The present paper concerns the study of atmospheric deposition of heavy metals, using a carpet-forming-moss species (Hypnum cupressiforme) as a bioindicator. It provides a complementary method to evaluate elemental deposition from the atmosphere to terrestrial systems. Compared with conventional precipitation analysis, it is an easier and cheaper method that ensures a high sampling density over the monitored area. The moss samples were collected over the whole territory of the country by following, more or less, a systematic sampling scheme, which is often used in environmental studies because it is convenient to implement in field campaigns, often providing good precision and complete coverage of the target population compared with random sampling. The 2010/2011 ICP vegetation moss survey data were used in this study. The unwashed, dried samples were digested completely by the microwave digestion method. The concentration (C) of selected trace metals (As, Cr, Cu, Ni, V and Zn) and conservative metals (Al, Li and Fe) were determined by ICP-AES and AAS (Cd and As) methods. To characterize the natural and the anthropogenic pattern of heavy metal deposition throughout the whole territory, the normalization process using lithium as a normalizing element was carried out on the C data for 11 elements of 44 moss samples. The obtained data set was used to compensate the natural variability of trace metals, so that the anthropogenic metal contributors could be detected and quantified. Descriptive statistics and multivariate analyses were used for the statistical treatment of the normalized concentration (NC) data using the MINITAB 17 software package. The statistical parameters of the NC data are discussed. The level of contamination was evaluated by calculating the enrichment factors, whereas the most probable local anthropogenic emitter sources were identified. The statistical analysis of NC data demonstrated that the normalization process is useful for evaluating the relative contributions of anthropogenic and natural sources of elemental deposition from the atmosphere to terrestrial systems, when the main pollution sources are from fine dust particles.

Optimization of Extraction of Toxic Metals from Medicinal Plants, Malva sylvestris L., and Pistacia lentiscus

The goal of the present study was to establish the best procedure for the extraction of metals from medicinal plants. Wet ashing, dry ashing, and microwave digestion methods were applied with different mixtures of nitric and hydrochloric acids using Malva sylvestris L. and Pistacia lentiscus leaves collected from two sites in Algeria. Cadmium, chromium, copper, lead, and zinc were determined by atomic absorption spectrometry. There were significant differences in the metal concentrations extracted by the methods. The highest efficiency from the leaves were obtained using a dry ashing method using 4:1 HNO3:HCl (v:v), and this approach was considered to be the optimum procedure. However, the wet and microwave digestion methods were suitable for this extraction but with reduced digestion efficiency. The extraction method has a significant influence on the measured metal concentrations, which emphasizes the need to choose the optimum procedure.

Separation/Preconcentration System Based on Emulsion-Induced Breaking Procedure for Determination of Cadmium in Edible Oil Samples by Flow Injection-Flame Atomic Absorption Spectrometry

In this work, a new procedure using extraction induced by emulsion breaking (EIEB) procedure has been developed for extraction/preconcentration of cadmium in various edible oils (canola, corn, hazelnut, olive, and sunflower oil) prior to its determination by flow injection (FI) flame atomic absorption spectrometry (FAAS). Five chemical variables (surfactant type, concentration of the surfactant, concentration of the nitric acid, emulsion breaking time, and temperature) were selected as the main factors affecting extraction efficiency, and two variables (sample flow rate and sample volume) were studied for optimizing flow injection conditions. The limits of detection of 1.53 and 1.55 μg L−1 were observed for cadmium when aqueous standard and oil-based standards were added to the samples for calibration, respectively. The linear range of cadmium in aqueous standard was varied in the range of 5.9–94 μg L−1. The precision of the EIEB procedure was obtained as 4.1 % by determination of ten replicates of 2.5 μg L−1 of cadmium, and the preconcentration factor 13.8 was obtained from only 4 mL of edible oil samples. The accuracy of the procedure was performed by comparison with the reference method based on the digestion of samples in a closed-vessel microwave oven and by spiking the samples with the known amounts of the cadmium in the form of oil-based standards. There were no statistical differences between the results obtained with the EIEB procedure and the reference microwave digestion method, and the recoveries were in the range of 97–104 %.

Final report of the key comparison CCQM-K106: Pb, As and Hg measurements in cosmetic (cream)

Cosmetics are used in practically all walks of life as a means of improving skin and beautifying complexion. In recent years, more and more attention has been paid to the cosmetic safety. In response to the cosmetic safety issue, the accurate measurement of the heavy metals in cosmetics is, therefore, particularly important. NMIs from different countries should establish their chemical metrology traceability system in this area, which includes both measurement methods research and certain CRMs development. It should be noted that because the matrix of many cosmetics is complex and the contents of the heavy metals are relatively low, it still is a challenging task to measure the analytes with high accuracy and precision. CCQM-K106 followed up CCQM pilot study 'CCQM-P128: Pb, As measurements in cosmetic (cream)' coordinated by the National Institute of Metrology, China (NIM) in 2009. The cream was selected as the testing material, which is widely used as a daily skin care worldwide. This is the first CCQM key comparison regarding the measurement of toxic metal elements with the cosmetic matrix, which includes pure water, liquid paraffin, silicone oil, synthetic squalane, hyaluronic acid, glycerin, propylene glycol, allantoin, preservative and so on. The aim of the CCQM-K106 is to demonstrate the capability of participating NMIs and designated institutes in measuring the contents of poisonous elements, including lead, arsenic and mercury in a cosmetic sample (cream), and support CMC claims relating to inorganic elements in cosmetic materials and similar chemical industry products. The cream matrix sample was prepared under the guidance of professional technicians. The formula of the cream was carefully chosen to match with a real cosmetic. The homogeneity and stability level of Pb, As and Hg in the cream sample were fit for the objective of the comparison. Each participant received two numbered bottles containing about 5g samples in each bottle. The instruction relating to CCQM-K106 was sent to each participant by e-mail, which consisted of technical protocol, results report form and inorganic core capabilities tables. The results were reported as mass faction (mg/kg). Calculation of the uncertainty expressed as a combined standard uncertainty and an expanded uncertainty at 95% confidence. In order to allow a sufficient evaluation of the comparison, the report was required to include a detailed description of the applied method of measurement, information about sample digestion and preparation, information about the reference material used for calibration. The methods of measurement were free to be selected by the participants. For the sample treatment, most of the participants used microwave digestion method. For instrumental determination, a variety of techniques such as ICP-MS, AAS, INAA were adopted by the participants. Most participants choose ID-ICP-MS method to measure Pb and Hg, which showed the better performance in terms of consistency and reliability of the measurement results. The reference mass fraction values and associated uncertainties were calculated by different statistic ways. As the result, the median and uncertainty of median were proposed as the key comparison reference value (KCRV) and its associated key comparison reference uncertainty after removal of suspected extreme values.In general, the performances of the majority of the CCQM-K106 participants are excellent, illustrating their measurement capability for Pb, As and Hg in a complex greasy matrix. The results can be used further by any participant to support its CMC claim at least for a borate buffer. That claim will concern the pH method employed by the participant during this comparison and will cover the used temperature(s) or the full temperature range between 15°C and 37 °C for the participant which measured pH values at the three temperatures. Main text.To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.The final report has been peer-reviewed and approved for publication by CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Determination of the alloying elements of nickel-based alloys designed for aviation application by inductively coupled plasma atomic emission spectrometry in combination with the microwave digestion method

A technique for determination of Al, Ti, Cr, Co, Nb, Mo, Ru, Ta, W, and Re in nickel-based alloys by inductively coupled plasma atomic emission spectrometry (ICP-AES) in combination with microwave digestion is described. The composition of the mixture used to dissolve the samples is formulated and the parameters of the microwave decomposition are adjusted. The relative error of determination of 0.1–20.00 wt % of elements does not exceed 4%.

MnZn ferrite synthesized by sol–gel auto-combustion and microwave digestion routes using spent alkaline batteries

The combination of a sol–gel auto-combustion method and a microwave digestion method was used to synthesize nanocrystalline MnZn ferrite powders using spent alkaline batteries. The overall process involved four steps: dissolution of spent batteries; the sol–gel formation; MnZn ferrite precursor powder formation; MnZn ferrite powder formation. The products were characterized for phase composition, morphology, and magnetic properties by inductively coupled plasma optical emission spectroscopy (ICP-OES), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis/differential scanning calorimetry (TG/DSC), X-ray diffraction (XRD), scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS), and vibrating sample magnetometer (VSM) techniques. IR spectra and DTA/DSC studies revealed that the combustion process is an oxidation–reduction reaction in which the NO3− ion is the oxidant and the citric acid is the reductant. Nanocrystalline MnZn ferrite powders were successfully prepared by a microwave digestion method using MnZn ferrite precursor powders at 120 °C for 15min. The results obtained showed the formation of single-phase MnZn ferrite powders with an average particle size of about 50nm. The results further revealed that microwave digestion conditions had a greater influence on the magnetic properties of the MnZn ferrite powders than the sol–gel auto combustion process alone.

Detection and Evaluation of Heavy Metal in Edible Fungi of Liaoning Province

Adopting microwave digestion and ICP-AES method while detecting Ni, Cr, Pb, Cd, As and Hg in edible fungus of Liaoning province, results show that the acceptance rate of heavy metal in lentinus edodes, oyster mushrooms, pleurotus eryngium, agrocybe cylindracea, agaricus bisporus, black fungus, coprinus comatus, cordyceps militaris was above 90%, Hg was not checked out, only in exceptional sampals Pb, Cd, Cr have checked out but not exceed, Ni and As out of limits, but the superscale was very small, the lentinus edodes in Liaoning province in a great measrue was safty.

Simple and Accurate Method for Routine Analysis of Heavy Metals in Soil, Plant, and Fertilizer

With environmental issues relating to heavy-metal contamination of natural resources becoming of increasing concern, there is an obvious need to have a method that can be used for routine analysis of a range of materials including soil, sediment, sewage sludge, plant, mineral and organic fertilizers, and other miscellaneous materials for heavy metals of concern. A single-step microwave digestion method was developed using aqua regia solution for digestion of finely ground samples for determining 15 heavy metals in soil, plant, and fertilizer materials using inductively coupled plasma–optical emission spectrometry (ICP-OES). Results on the recoveries of 15 heavy metals added via certified standard reference sample to soil, plant, or fertilizer samples showed that the results varied with the metal and the substrate, and with few exceptions, the results were satisfactory. The method is simple, rapid, and accurate and seems ideal for the routine analyses of a range of materials. Using microwave-assisted digestion, an analyst can perform more than 100 analyses in a working day.

Lithographically Cut Multiwalled Carbon Nanotubes: Opening Caps, Controlling Length Distribution, and Functionalization

This work presents a microwave digestion heating method using a 40 ml mixture of potassium permanganate and sulfuric acid (3/1 mol) to cut, end-open, and functionalize as-prepared multiwalled carbon nanotubes (A-MWCNTs). Also, the ability of the microwave digestion method was studied at different reaction times (5, 10, 20, 30, and 40 minutes). To harness the extent of treatment, shortened multiwalled carbon nanotubes (S-MWCNTs) were fully characterized by UV-visible, Fourier transform infrared spectroscopy, and Raman spectroscopies, as well as, transmission electron microscopy and optical microscopy. The results showed that, with this mild treatment, the A-MWCNTs (>80 µm) were efficiently and significantly shortened to below 1 µm after 40 minutes. Also, heating the closed reaction vessel under microwave irradiation at 90°C for 20 minutes was very effective in the functionalization of MWNTs. At the same time, the S-MWCNTs formed the best state of dispersion in water without the help of surfactants that provided possibility for further functionalizations. For the first 10 minutes, crystallinity increased then decreased until 20 minutes, and after that improved slightly. Finally, the mechanism of this process is explained schematically. This method could be used as high-efficiency and damage-free process to the cut, end-open, and functionalization of CNTs that led to dispersion of CNTs and ultimately for such application.

Performance comparison of material tests for cadmium and lead in food contact plastics

Based on the Japanese Food Sanitation Law, the performances of official and alternative material test methods for cadmium (Cd) and lead (Pb) in food contact plastics were compared. Nineteen laboratories participated to an interlaboratory study, and quantified Cd and Pb in three PVC pellets. in the official method, a sample is digested with H2SO4, taken up in HCl, and evaporated to dryness on a water bath, then measured by atomic absorption spectrometry (AAS) or inductively coupled plasma-optical emission spectrometry (ICP-OES). Statistical treatment revealed that the trueness, repeatability (RSDr) and reproducibility (RSDr) were 86-95%, 3.1-9.4% and 8.6-22.1%, respectively. The values of the performance parameters fulfilled the requirements , and the performances met the test specifications. The combination of evaporation to dryness on a hot plate and measurement by AAS or ICP-OES is applicable as an alternative method. However, the trueness and RSDr were inferior to those of the official method. The performance parameters obtained by using the microwave digestion method (MW method) to prepare test solution were better than those of the official method. Thus, the MW method is available as an alternative method. Induced coupled plasma-mass spectrometry (ICP-MS) is also available as an alternative method. However, it is necessary to ensure complete digestion of the sample.

Assessment of trace element levels in muscle tissues of fish species collected from a river, stream, lake, and sea in Sakarya, Turkey.

Levels of some trace and essential elements, including Al, B, Ba, Cr, Cu, Fe, Mn, Ni, Sr, and Zn, were determined in 17 different fish species from Sakarya River, Çark Stream, Sapanca Lake, and Western Black Sea using ICP-OES after microwave (MW) digestion procedure. During preparation of samples for analysis, wet and MW digestion methods were also compared. Accuracy of the digestion methods was checked by the analysis of DORM-3 reference material (Fish Protein Certified Reference Material for Trace Metals). Concentrations of trace elements were found as Al: 6.5–48.5, B: 0.06–3.30, Ba: 0.09–2.92, Cr: 0.02–1.64, Cu: 0.13–2.28, Fe: 7.28–39.9, Mn: 0.08–11.4, Ni: 0.01–26.1, Sr: 0.17–13.5, and Zn: 11.5–52.9 µg g−1. The obtained results were compared with other studies published in the literature. Trace element levels in various fish species collected from waters in Sakarya region were found to be below limit values provided by Turkish Food Codex (TFC), Food and Agriculture Organization (FAO), and World Health Organization (WHO).

Determination of Bromine in Plastics by ICP-MS Using Microwave Digestion

A microwave digestion method for the determination of bromine in polyethylene (BCR 680 and 681) and peach leaves (SRM1547) by inductively coupled plasma mass spectrometry (ICP/MS) has been investigated. In the microwave digestion system, a sample of 0.1–0.3 g was weighed and 7 mL of nitric acid and 1 mL of hydrogen peroxide were added in a quartz insert. The insert was used within the standard TFM vessel which 6 mL of 10% hydrogen peroxide was added. The accuracy of the digestion method was evaluated. The recovery and the standard deviation (n = 3) for the bromine tested was 109% and 9.4%. The results obtained by the present method were in good agreement with the certified values.

Quality Determination of Biomass for Combustion: A New High-Throughput Microwave Digestion Method Prior to Elemental Analysis by Inductively Coupled Plasma–Optical Emission Spectroscopy

A high content of minerals in biomass feedstock may cause fouling, slagging, and corrosion in the furnace during combustion. Here, a new pressurized microwave digestion method for biomass digestion prior to elemental analysis is presented. This high-throughput method is capable of processing approximately 48 samples per hour with reduced laboratory hazards and waste because only a very small volume of hydrofluoric acid is used. Concentrations of 12 elements (Al, Ca, Cd, Cu, Fe, K, Mg, Mn, Na, P, Si, and Zn) were determined using inductively coupled plasma–optical emission spectroscopy (ICP–OES). National Institute of Standards and Technology (NIST) standard reference materials (SRMs) 1515 apple leaves and 1575a pine needles were used for method validation. Recoveries of the 12 elements in the NIST SRMs ranged from 93 to 115%. A comparison of the high-throughput method with the European Union (EU) standard method showed agreements in the range from 98 to 115% (except for Al) when the elements were quantified in plant material of the energy crop Miscanthus × giganteus.

Quantitative elemental analysis of Celocia argentea leaves by ICP-OES technique using various digestion methods

Abstract Aim Quantification of macronutrient, micronutrient and toxic elements from the leaves of Celocia argentea by inductively coupled plasma-optical emission spectrometry (ICP-OES) and to report efficient, reliable, eco friendly method of digestion for better recovery of the elements. Methods The five digestion methods are studied included, dry ashing method with HNO3/HCl, wet digestion method with HNO3/HClO4 and HNO3/H2O2, microwave digestion with HNO3/HClO4 and HNO3/H2O2. ICP-OES operating parameter was optimized at radial and axial viewing along with the radio-frequency power, sample flush time and gas flow rate. The results of the elemental quantification were statistically analyzed using one way analysis of variance (ANOVA) by Kruskal–Wallis test. Results C. argentea exhibits good quantity of macronutrients like Mg, Ca S, P, K and Fe. The ashing and microwave digestion method were found to more reliable as compare to wet digestion method and hence recommended for better recovery. The element Ca, Cu and Fe gives better recovery by ash and microwave digestion method as compare to wet digestion method. Toxic elements show their concentration below permissible limit. Conclusion All the nutrients as well as toxic elements are quantified successfully by ICP-OES technique by all methods of digestion. Dry and wet digestion methods are tedious and time consuming compare to microwave digestion method, which is greener and simpler. Kruskal–Wallis test can be employed for non-parametric methods to compare more than two population average which do not require any specific form of the distribution of the population. The C. argentea can be used as supplementary food for deficiency of minerals like Fe, Mg and Ca.

Heavy Metal Pollution Characteristics in the Sediment of Elephant Lake in Nanchang City, Jiangxi

In order to understand the pollution features of heavy metals in sediments of Elephant Lake in Nanchang city, sediment samples were collected and detected .Using microwave digestion and BCR Method for sediment pre-treatment, the concentrations of heavy elements were measured by ICP-OES emission spectrometer. Sediment heavy metal contents were in descending order of Zn&gt; Pb&gt; Cu&gt; Cr&gt; As&gt; Cd. According to the national soil environmental quality standards of P.R.China, there was Cd contamination in lakebed mud. And five kinds of metals existed mainly in oxidizable (F3) and residual (F4) , indicating less risk of migration of heavy metals .

Determination of antimony in bottled water and polyethylene terephthalate bottles: a routine laboratory quality check

The paper describes a modified and optimised conventional wet ashing method for the determination of antimony (Sb) in polyethylene terephthalate (PET) bottles used for bottling sparkling and still water. The modified optimum conventional wet ashing method was applied as the digestion method to extract Sb from PET bottles, and the extracted Sb analysed using flame atomic absorption spectrometry (F-AAS), and in bottled water, Sb was analysed with hydride vapour generator atomic absorption spectrometry (HVG-AAS). Microwave digestion method was also used as described above for comparison. The concentrations of Sb obtained using modified optimum conventional wet ashing and microwave digestion protocols were from 169 ± 13 to 285 ± 17 μg g−1 and from 123 ± 0.5 to 249 ± 18 μg g−1, respectively. The average concentration of Sb in bottled water samples using the HVG-AAS was 0.183 ± 0.013 μg L−1, with a range of 0.012 ± 0.001 to 0.358 ± 0.006 μg L−1. Sb concentration increased marginally with longevity of storage, but still remained well below the various guidelines for Sb levels in drinking water.