High-performance Liquid Chromatography-inductively Coupled Plasma-mass Spectrometry Research Articles

Urine Arsenic and Prevalent Albuminuria: Evidence From a Population-Based Study

Long-term arsenic exposure is a major global health problem. However, few epidemiologic studies have evaluated the association of arsenic with kidney measures. Our objective was to evaluate the cross-sectional association between inorganic arsenic exposure and albuminuria in American Indian adults from rural areas of Arizona, Oklahoma, and North and South Dakota. Cross-sectional. SETTING & PARTIPANTS: Strong Heart Study locations in Arizona, Oklahoma, and North and South Dakota. 3,821 American Indian men and women aged 45-74 years with urine arsenic and albumin measurements. Urine arsenic. Urine albumin-creatinine ratio and albuminuria status. Arsenic exposure was estimated by measuring total urine arsenic and urine arsenic species using inductively coupled plasma mass spectrometry (ICPMS) and high-performance liquid chromatography-ICPMS, respectively. Urine albumin was measured by automated nephelometric immunochemistry. The prevalence of albuminuria (albumin-creatinine ratio ≥30 mg/g) was 30%. Median value for the sum of inorganic and methylated arsenic species was 9.7 (IQR, 5.8-15.6) μg per gram of creatinine. Multivariable-adjusted prevalence ratios of albuminuria (albumin-creatinine ratio ≥30 mg/g) comparing the 3 highest to lowest quartiles of the sum of inorganic and methylated arsenic species were 1.16 (95% CI, 1.00-1.34), 1.24 (95% CI, 1.07-1.43), and 1.55 (95% CI, 1.35-1.78), respectively (P for trend <0.001). The association between urine arsenic and albuminuria was observed across all participant subgroups evaluated and was evident for both micro- and macroalbuminuria. The cross-sectional design cannot rule out reverse causation. Increasing urine arsenic concentrations were cross-sectionally associated with increased albuminuria in a rural US population with a high burden of diabetes and obesity. Prospective epidemiologic and mechanistic evidence is needed to understand the role of arsenic as a kidney disease risk factor.

HPLC-HG-ICP-MS: a sensitive and selective method for inorganic arsenic in seafood

The addition of an online post-column hydride generation (HG) step to the commonly used high-performance liquid chromatography inductively coupled plasma-mass spectrometry (HPLC-ICP-MS) setup for arsenic speciation proved to significantly improve the detection limits for the determination of inorganic arsenic (iAs) as arsenate in seafood samples, where the limit of detection and limit of quantification were found to be 0.0004 and 0.0014 mg kg(-1), respectively with HG. HG as an additional step further added to the selectivity of the determination of the iAs species and increased the detection and quantification of low levels of iAs (<0.002 mg kg(-1)) in samples with complicated matrices.

Geochemistry of iodine-rich groundwater in the Taiyuan Basin of central Shanxi Province, North China

This paper presents the results of studies on the geochemistry of iodine-rich groundwater in the southwest of the Taiyuan Basin, Shanxi Province, North China. A total of 950 water samples were collected from shallow (≤50m), medium-depth (50–200m) and deep (≥200m) wells in the southwestern Taiyuan Basin. Total and inorganic iodine concentrations, including species of iodide and iodate, were determined using inductively coupled plasma mass spectrometry (ICP-MS) and high performance liquid chromatography- ICP-MS (HPLC-ICP-MS). The results indicate that there are 76.8%, 70.3% and 85.2% of groundwater samples from the above-mentioned three levels, respectively, that exceed the national drinking water standard for iodine (150μg/L), with the highest iodine concentration of up to 4117μg/L, 27 times higher than the standard, tested in shallow groundwater. The main species of iodine in the groundwater is iodide ion with a small proportion of iodate. Organic iodine was detected in about 60% of the water samples with relatively low content. The main factors causing the high iodine concentrations in groundwater include the unique topography, geomorphologic features and aquifer structures in the study area, resulting in hindered movement of groundwater. Furthermore, salinization of surface soil in the low-lying lands intensifies the elevation of iodine concentrations in shallow groundwater. The enrichment of iodine in groundwater is inextricably linked to the geological environment of marine, lacustrine and fluvial sedimentations. The results of this research could provide scientific bases for optimization of water supply scheme in China's iodine excess areas.

Total and inorganic arsenic in fish samples from Norwegian waters

The contents of total arsenic and inorganic arsenic were determined in fillet samples of Northeast Artic cod, herring, mackerel, Greenland halibut, tusk, saithe and Atlantic halibut. In total, 923 individual fish samples were analysed. The fish were mostly caught in the open sea off the coast of Norway, from 40 positions. The determination of total arsenic was carried out by inductively coupled plasma mass spectrometry following microwave-assisted wet digestion. The determination of inorganic arsenic was carried out by high-performance liquid chromatography–ICP-MS following microwave-assisted dissolution of the samples. The concentrations found for total arsenic varied greatly between fish species, and ranged from 0.3 to 110 mg kg–1 wet weight. For inorganic arsenic, the concentrations found were very low (<0.006 mg kg–1) in all cases. The obtained results question the assumptions made by the European Food Safety Authority (EFSA) on the inorganic arsenic level in fish used in the recent EFSA opinion on arsenic in food.

Arsenic speciation in soils and Erica andevalensis Cabezudo & Rivera and Erica australis L. from São Domingos Mine area, Portugal

Arsenic is very abundant in the Iberian Pyrite Belt (IPB) and it might have hazardous consequences for plants. The chemical speciation is an important factor to take into account in toxicity evaluations. Arsenate is analogous to phosphate and it can seriously interfere with cellular processes. In the present study we have analysed by high performance liquid chromatography-inductively coupled plasma-mass spectrometry (HPLC-ICP-MS) the arsenic speciation in soils from São Domingos mine area (IPB) and arsenate resulted to be the major species. The arsenic content and speciation analysis have been carried out also in two metal tolerant species from that area: Erica andevalensis, endemic heather from the mining areas of the Southwest Iberian Peninsula, and Erica australis, a widely distributed species. The total content of arsenic ranged in soils from 194 to 7924mgkg−1 (dry mass), and from 1 to 24.4mgkg−1 in E. andevalensis and from 2.7 to 11.6mgkg−1 in E. australis. The organic forms of arsenic were almost absent, with only dimethylarsinate (DMA) found in some samples of E. andevalensis. These plant species must possess different tolerance mechanisms, as E. australis accumulates mainly arsenite, while in E. andevalensis arsenate is the most abundant species in some cases.

Arsenic Speciation in Tobacco and Cigarette Smoke

Abstract Arsenic is one of the metals found in cured tobacco and mainstream cigarette smoke. Levels of arsenic in modern filtered cigarette smoke range from sub-ppm to a few tens of ppms. To enable accurate smoke toxicity assessment on arsenic in cigarette smoke, it is desirable to establish its chemical forms in addition to total quantities because different arsenic compounds possess different toxicological potentials. Progress has been made on measuring the arsenic speciation in tobacco and mainstream cigarette smoke by using a combination of synchrotron-based X-ray absorption spectroscopy and high-performance liquid chromatography- inductively coupled plasma mass spectrometry (HPLC-ICP-MS). In this paper, we describe the experimental procedures developed together with the main findings. A transient redox transformation between As(V) and As(III) was confirmed in freshly generated mainstream smoke. Potential areas for future research are highlighted in order to further our understanding of the speciation mechanism for arsenic in tobacco products.

Selenium speciation analysis of Misgurnus anguillicaudatus selenoprotein by HPLC–ICP–MS and HPLC–ESI–MS/MS

Analytical methods for selenium (Se) speciation were developed using high-performance liquid chromatography (HPLC) coupled to either inductively coupled plasma mass spectrometry (ICP–MS) or electrospray ionization tandem mass spectrometry (ESI–MS/MS). Separations of selenomethionine (Se-Met) and selenocysteine (Se-(Cys)2) with favorable peak shape and resolution were obtained by both HPLC-ICP-MS and HPLC–ESI–MS/MS. Both methods achieved low limits of detection, high sensitivity and favorable stability. With HPLC–ESI–MS/MS, signal suppression was observed when complex matrix was co-eluted, but excellent structural characterization was still achieved. Thus, HPLC-ICP-MS is better for the detection of Se species, and HPLC–ESI–MS/MS is essential for molecular identification and confirmation. A water-soluble selenoprotein from purified M. anguillicaudatus muscle tissue was analyzed by the two complementary systems (HPLC-ICP-MS and HPLC–ESI–MS/MS) with high sensitivity and accuracy. The results demonstrated that Se-Met was the predominant selenoamino acid in the purified selenoprotein from M. anguillicaudatus muscle tissue, and the concentration of Se-Met in the selenoprotein was 6.280 mg/kg (dry mass). In addition, in HPLC-ICP-MS, an unknown Se-containing compound with similar polarity to Se-(Cys)2 was discovered. Using complementary data from HPLC–ESI–MS/MS, it was determined that this unknown Se-containing compound was not Se(Cys)2.

Isolation of Selenoprotein-P and Determination of Se Concentration Incorporated in Proteins in Human and Mouse Plasma by Tandem Heparin Affinity and Size-exclusion Column HPLC-ICPMS

Sel-P is considered to be the most important selenoprotein for evaluating the selenium (Se) status in the body. To isolate and determine Sel-P in plasma, we have developed an analytical method combining heparin affinity (AF) and size-exclusion column (SEC) high-performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICPMS). We used this method to validate the adsorption efficiency of selenoproteins on a heparin AF column, and to then determine the Se concentrations incorporated in proteins in human and mouse plasma. The adsorption efficiency of Sel-P on a heparin column was more than 90% for both human and mouse plasma. Tandem AF and SEC separation proved to be useful for determining the Se concentrations incorporated in Sel-P in mouse plasma, but not in human plasma, because of nonspecific adsorption of plasma-extracellular glutathione peroxidase (eGPx) and albumin on the heparin AF column. Ultimately, we used the tandem AF and SEC separation method for mouse plasma and SEC separation alone for human plasma. The Se concentration incorporated in selenoproteins determined by our method showed good agreements with the total Se concentration determined following acid digestion.

Metallomic study of selenium biomolecules metabolized by the microalgae Chlorella sorkiniana in the biotechnological production of functional foods enriched in selenium

The optimization of culture conditions for selenium (Se) bioaccumulation in the microalgae Chlorella sorokiniana growth in a Na2SeO4-enriched medium was explored, in order to obtain a suitable approach for the biotechnological production of a Se-enriched food. Se concentration (as Na2SeO4) in the culture medium until 100 μg ml–1 allows the growth of algae colonies during long periods of time, until 300 h, but higher concentrations cause the collapse of the colony. The bioaccumulation process causes a concentration of Se in algae in the order of 3 μg g–1 in about 100 h. A metallomic analytical approach based in the coupling high-performance liquid chromatography-inductively coupled plasma-mass spectrometry (HPLC-ICP-MS), which uses two chromatographic switched columns (C-18 and chiral columns) with ICP-MS detection, has been applied to characterize the different Se metabolites, including chiral forms, in both the algae and culture medium. The results reveal that selenate present in the culture is biotransformed in selenocystine (SeCys2), selenomethylselenocysteine (SeMeSeCys), and mainly selenomethionine (SeMet) by the algae, although appreciable concentration of Se(VI) is also present in cells. When algae are cultured under sulfur (S) deficiency conditions, the accumulation of Se in the cell is enhanced owing to the great chemical similarity between S and Se that promotes the substitution of S by Se in the cell metabolism, therefore, SeMet concentration in the algae increases from about 7 to 15 μg g–1 and Se(VI) from 15 to 25 μg g–1, after 500 h of exposure.

Speciated urinary arsenic as a biomarker of dietary exposure to inorganic arsenic in residents living in high-arsenic areas in Latium, Italy

Current knowledge indicates that total urinary arsenic is not a suitable biomarker of exposure to toxic, i.e., inorganic, arsenic (iAs), whereas measurement of iAs and its methylated metabolites in urine using speciation analysis provides much more reliable estimates of exposure. The relative proportions of urinary iAs, monomethylarsonate (MA), and dimethylarsinate (DMA) can be used as a measure of methylation capacity, provided that there are no confounding factors such as consumption of food rich in DMA or containing As compounds metabolized to DMA.We analyzed by gradient elution anion-exchange HPLC-ICP-MS (high-performance liquid chromatography-inductively coupled plasma-mass spectrometry) urine samples from 153 residents in Latium (central Italy) chronically exposed to iAs via water and food. Excluding 26 subjects that excreted high concentrations of arsenobetaine (AB) (≥50 μg As/L) due to seafood consumption, iAs and related metabolites summed up about 75 % of total urinary As as measured by ICP-MS. AB and other organoarsenic compounds were detected at low concentrations in all urine samples. Considering all subjects, the sum of iAs and metabolites ranged 2–72 μg/L and relative proportions were iAs 14 %, MA 13 %, and DMA 72 % (median values), with a wide individual variability.In addition to the above arsenocompounds, the analytical method used in this study enabled the detection of dimethylthioarsinic acid (DMTA), which was found to be present in 33 % of the samples at concentrations ranging mostly from trace amounts to ~6 μg As/L. We found that part of the certified DMA content of human urine reference material SRM 2669 was present as DMTA. Four unknown arsenicals were also detected as minor species in a small proportion of samples.

Selenium compounds in selenium-enriched cabbage

For the study, cabbage (Brassica oleracea var. capitata L.) and red cabbage (Brassica oleracea var. capitata L. f. rubra) were treated with Na selenate. Cabbage was foliarly sprayed twice with 20 mg Se(VI) L–1, while red cabbage was fertilized twice with 0.5 mg Se(VI) L–1. Despite the high dose of Se, no toxic effects were observed on cabbage plants. The total Se concentration in cabbage leaves was 4.80 ± 0.25 μg Se g–1 (DM) and in red cabbage 0.96 ± 0.04 μg Se g–1 (DM). Soluble Se compounds were extracted from parts of cabbage with protease XIV, resulting in 49 % of soluble Se from roots, 59 % from leaves, and 65 % from stems. In red cabbage, the corresponding figures were 28 % of soluble Se in roots, 31 % in stems, and 43 % in leaves. Se species were determined in the enzymatic extracts using ion exchange high-performance liquid chromatography-inductively coupled plasma-mass spectrometry (HPLC-ICP-MS). The main Se species found in all parts of cabbage and red cabbage was selenomethionine (SeMet), which in roots represented 94 and 55 % of the soluble Se content in cabbage and red cabbage, respectively. In stems and leaves of cabbage, SeMet represented only 23 % of the soluble Se content. In stems of red cabbage SeMet represented 80 % and in leaves 41 % of the soluble Se content. We observed that traces of Se(VI) were present in upper parts of both plants.

Arsenic speciation in freshwater snails and its life cycle variation

Terrestrial snails are consumed by humans occasionally and they are an important food source for many creatures including fish and birds. Little is known about arsenic speciation in these gastropods, let alone life cycle variations. Here we report on the arsenic speciation in freshwater snails from Pender Island and Vancouver Island, B.C., Canada, which was determined on methanol/water extracts (43-59% extraction efficiency) by using high performance liquid chromatography-inductively coupled plasma-mass spectrometry (HPLC-ICP-MS) and HPLC-electrospray tandem mass spectrometry. The tetramethylarsonium ion, oxo-arsenosugars and thio-arsenosugars are the main arsenic species encountered. Arsenobetaine, which is commonly found in the marine environment, is minor. Live bearing snails Viviparidae sp. from Pender Island were maintained in aquaria and the arsenic speciation in the unborn, newly born, and adult animals was monitored. Oxo-arsenosugars predominate in the adults, whereas thio-arsenosugars seem to predominate in juveniles, suggesting that these arsenicals are snail metabolites.

Environmental Exposure to Silver and its Health Effects

Silver (Ag) possesses a well-known antibacterial activity and has been used for medical treatment and cosmetics such as wound dressing and deodorant powders. Occupational Safety and Health Administration (OSHA) and Mine Safety and Health Administration (MSHA) proposed that the permissible exposure limit (PEL) for both metallic and most soluble Ag compounds should be 0.01 mg/m3. Argyria and argyrosis are known to be caused by deposition of insoluble Ag in the dermis and cornea/conjunctiva. However, the metabolic behavior and biological roles of Ag have not been well characterized in mammals. Ag can be absorbed into the systemic circulation from drinking water, and also through parenteral routes such as inhalation and dermal exposure. Experimental studies have demonstrated that Ag+ induces and binds to metallothionein I and II (MTs), which are cysteine-rich proteins, in cells. MTs are major cytoplasmic metal binding proteins and thereby reduce cellular damage caused by toxic heavy metals including Ag. Profiles of Ag distribution in MTs and other Ag-binding proteins can be determined using high performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICP-MS). This technique directly provides information on the intracellular behavior of Ag, which is important for elucidating the mechanism underlying Ag toxicity. Silver nanoparticles (AgNPs) are also commercially used mainly as antimicrobial agents. Despite the widespread use of AgNPs, relatively few studies have been undertaken to evaluate the health effects of AgNP exposure. In the present paper, we discuss the absorption, toxicodynamics, and metabolism of both Ag and AgNPs in mammals and their health effects.

Arsenic Speciation in Plankton Organisms from Contaminated Lakes: Transformations at the Base of the Freshwater Food Chain

The two complementary techniques high performance liquid chromatography-inductively coupled plasma-mass spectrometry (HPLC-ICP-MS) and X-ray absorption near edge structure (XANES) analysis were used to assess arsenic speciation in freshwater phytoplankton and zooplankton collected from arsenic-contaminated lakes in Yellowknife (Northwest Territories, Canada). Arsenic concentrations in lake water ranged from 7 μg L(-1) in a noncontaminated lake to 250 μg L(-1) in mine-contaminated lakes, which resulted in arsenic concentrations ranging from 7 to 340 mg kg(-1) d.w. in zooplankton organisms (Cyclops sp.) and from 154 to 894 mg kg(-1) d.w. in phytoplankton. The main arsenic compounds identified by HPLC-ICP-MS in all plankton were inorganic arsenic (from 38% to 98% of total arsenic). No other arsenic compounds were found in phytoplankton, but zooplankton organisms showed the presence of organoarsenic compounds, the most common being the sulfate arsenosugar, up to 47% of total arsenic, with traces of phosphate sugar, glycerol sugar, methylarsonate (MMA), and dimethylarsinate (DMA). In the uncontaminated Grace Lake, zooplankton also contained arsenobetaine (AB). XANES characterization of arsenic in the whole plankton samples showed As(V)-O as the only arsenic compound in phytoplankton, and As(III)-S and As(V)-O compounds as the two major inorganic arsenic species in zooplankton. The proportion of organoarsenicals and inorganic arsenic in zooplankton depends upon the arsenic concentration in lakes and shows the impact of arsenic contamination: zooplankton from uncontaminated lake has higher proportions of organoarsenic compounds and contains arsenobetaine, while zooplankton from contaminated area contains mostly inorganic arsenic.

Fractionation and speciation of arsenic in fresh and combusted coal wastes from Yangquan, northern China

In this study, the content and speciation of arsenic in coal waste and gas condensates from coal waste fires were investigated, respectively, using the digestion and sequential extraction methods. The fresh and fired-coal waste samples were collected from Yangquan, which is one of the major coal production regions in northern China. High-performance liquid chromatography-inductively coupled plasma-mass spectrometry (HPLC-ICP-MS) was used to determine the concentrations of four major arsenic species [As(III), As(V), monomethylarsonic acid (MMA) and dimethylarsenic acid (DMA)] in the extracts, while ICP-MS was used to measure total As content. Arsenic content in the investigated coal wastes and the condensate ranges between 23.3 and 69.3 mg/kg, which are higher than its reported average content in soils. Arsenic in coal waste exists primarily in the residual fraction; this is followed in decreasing order by the organic matter-bound, Fe-Mn oxides-bound, exchangeable, carbonates-bound, and water-soluble fractions. The high content of arsenic in the condensates indicates that combustion or spontaneous combustion is one of the major ways for arsenic release into the environment from coal waste. About 15% of the arsenic in the condensate sample is labile and can release into the environment under leaching processes. The water extractable arsenic (WEA) in the fresh coal waste, fired coal wastes, and the condensate varied between 14.6 and 341 μg/kg, with As(V) as the major species. Furthermore, both MMA and DMA were found in fresh coal wastes, fired coal wastes, and the condensate.

Quantitative determination of small selenium species in human serum by HPLC/ICPMS following a protein-removal, pre-concentration procedure

Protein precipitation was incorporated into a sample preparation method for the quantitative determination of small "non-protein" selenium species in human serum by high-performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC/ICPMS). The advantages of cleaner matrix and concomitant concentration of the small compounds result in quantification limits in the native serum at the sub-micrograms Se per litre level. Spiking experiments with methyl 2-acetamido-2-deoxy-1-seleno-β-D-galactopyranoside (selenosugar 1), trimethylselenonium ion, selenomethionine, methylselenocysteine (MeSeCys) and selenate yielded recoveries from 73% to 103%. Selenite had a low recovery (44%), possibly owing to protein binding. The validated method was applied to serum samples from two volunteers before and after ingestion of a selenium food supplement. HPLC/ICPMS analysis showed, besides ingested selenate, the presence of selenosugar 1 and trace amounts of MeSeCys and methyl 2-amino-2-deoxy-1-seleno-β-D-galactopyranoside, which have not been reported in human serum before.

Arsenic biotransformation and volatilization in transgenic rice

• Biotransformation of arsenic includes oxidation, reduction, methylation, and conversion to more complex organic arsenicals. Members of the class of arsenite (As(III)) S-adenosylmethyltransferase enzymes catalyze As(III) methylation to a variety of mono-, di-, and trimethylated species, some of which are less toxic than As(III) itself. However, no methyltransferase gene has been identified in plants. • Here, an arsM gene from the soil bacterium Rhodopseudomonas palustris was expressed in Japonica rice (Oryza sativa) cv Nipponbare, and the transgenic rice produced methylated arsenic species, which were measured by inductively coupled plasma mass spectrometry (ICP-MS) and high-performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICP-MS). • Both monomethylarsenate (MAs(V)) and dimethylarsenate (DMAs(V)) were detected in the roots and shoots of transgenic rice. After 12 d exposure to As(III), the transgenic rice gave off 10-fold greater volatile arsenicals. • The present study demonstrates that expression of an arsM gene in rice induces arsenic methylation and volatilization, theoretically providing a potential stratagem for phytoremediation.

Low-level determination of six arsenic species in urine by High Performance Liquid Chromatography-Inductively Coupled Plasma-Mass Spectrometry (HPLC-ICP-MS).

Many methods that have been used to speciate arsenic metabolites in urine are unable to adequately resolve the chromatographic peaks for arsenite (As[iii]) and arsenobetaine (AsB). We present a High Performance Liquid Chromatography-Inductively Coupled Plasma-Mass Spectrometry (HPLC-ICP-MS) method that has been optimized to reliably measure the following six arsenic species in human urine: As[iii], arsenate (As[v]), monomethylarsonous acid (MMA[iii]), monomethylarsonic acid (MMA[v]), dimethylarsinic acid (DMA[v]) and AsB. The method was evaluated with regards to changes in mobile phase, accuracy and precision. The ability to quantify the six species in a given sample depended on the low detection limits of the method-0.06 μg L-1 for AsB, 0.11 μg L-1 for As[iii], 0.08 μg L-1 for DMA[v], 0.12 μg L-1 for MMA[v] and 0.15 μg L-1 for As[v]. The procedure was used to measure the six arsenic species in urine samples from 387 individuals in southeast Michigan who are chronically exposed to slightly elevated levels of arsenic in their drinking water. The DMA[v] was detected in 99.2% of samples, AsB in 98.2%, MMA[v] in 73.4%, As[iii] in 45.0%, and As[v] in 27.1%. No MMA[iii] was detected even in samples analyzed within 6 hours after collection. The results raise some doubt as to whether MMA[iii] is a significant metabolite in urine of people exposed to arsenic concentrations below 20 μg L-1 in their drinking water.

Speciation of mercury in liquid cosmetic samples by ionic liquid based dispersive liquid–liquid microextraction combined with high-performance liquid chromatography-inductively coupled plasma mass spectrometry

Ionic liquid based dispersive liquid–liquid microextraction (IL-DLLME) combined with high performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICP-MS) for the determination of mercury species in liquid cosmetic samples is described. Firstly mercury (Hg2+), methylmercury (MeHg+) and ethylmercury (EtHg+) were complexed with ammonium pyrrolidinedithiocarbamate (APDC), and then the complexes were extracted into 1-hexyl-3-methylimidazolium hexafluorophosphate ([C6MIM][PF6]) using DLLME. Under the optimized conditions, the enrichment factors of 760, 115, 235 for Hg2+, MeHg+ and EtHg+ were obtained from only 5.00 mL sample solution. The detection limits of the analytes (as Hg) were 1.3 ng L−1 for Hg2+, 7.2 ng L−1 for MeHg+ and 5.4 ng L−1 for EtHg+, respectively. The relative standard deviation (n = 10) of 0.5 ng mL−1 Hg2+, MeHg+ and EtHg+ were 7.4%, 5.2% and 2.3%, respectively. Finally, the developed method was successfully applied for the speciation of mercury in four liquid cosmetic samples, Hg2+ was found as the main species in these samples, and a spike test was performed to verify the accuracy of the method.

An approach to the arsenic status in cardiovascular tissues of patients with coronary heart disease

Among non-cancer effects of arsenic, cardiovascular diseases have been well documented; however, few are known about the arsenic fate in cardiovascular tissues. We studied the analytic bioinorganic arsenic behaviour in cardiovascular tissues from an arsenic exposure coronary heart disease patient group from Antofagasta-Chile against a small unexposed arsenic coronary heart patient group. Total arsenic concentrations were measured in pieces of cardiovascular tissues of the arsenic-exposed and unexposed coronary heart patient groups by hydride generation atomic absorption spectrometry (HG-AAS); speciation analysis was made by high performance liquid chromatography-inductively coupled plasma-mass spectrometry (HPLC-ICP-MS). Pieces of auricle (AU), mammary artery (MAM), saphenous vein (SAP) and fat residuals (FAT) were considered in this study. The arsenic concentrations in AU and MAM tissues were significantly different between both groups of patients. Also, it was demonstrated that the AU is an 'As(3+) target tissue.' Otherwise, linking of the total concentrations of arsenic with conditional variables and variables related to medical geology factors allowed us to infer that the latter are more important for the cardiovascular risk of arsenic exposure in the Antofagasta region. Knowledge of total arsenic and the prevalence of the trivalent ion (As(3+)) in the AU of patients could contribute to understanding the effect of arsenic on cardiovascular diseases.