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Minerals are important components of thousands of enzymes and other compounds in the body. Although the content of minerals in the human body is small, their importance is immense. Edible insects can provide many of these minerals in abundance, and are therefore thought to be a good source of micronutrients. This study dealt with the effect of a rearing temperature and feed on the mineral content and on the content of selected heavy metals in mealworm (Tenebrio molitor). Mealworm larvae were kept at temperatures of 15, 20 and 25°C, and fed with wheat bran, lentil flour and a mixture of both. The types of feed for the experimental groups were chosen purposefully, considering the availability on site, price and especially the impact on the nutrition composition suitable for human. The concentrations of the most significant elements in terms of human nutrition concerns, that is zinc and copper, were determined with inductively coupled plasma mass spectrometry. The results showed that the normality condition was not achieved for Ca, Fe, P and Pb (p, TBU in Zlin [IGA/FT/2020/010]; project BUT in Brno [FEKT-S-20-6215]

International audience; This study assesses the impact of the farming system on the levels of copper, zinc, arsenic, cadmium, lead and mercury in pig tissues from three types of production (Organic (n = 28), Label Rouge (n = 12) and Conventional (n = 30)) randomly sampled in different slaughterhouses. All the concentrations were below regulatory limits. In muscles, Cu, Zn and As were measured at slightly higher levels in organic samples but no differences between organic and Label Rouge was observed. Livers from conventional and Label Rouge pig farms exhibited higher Zn and Cd contents than the organic ones, probably due to different practice in zinc or phytase supplementation of fattening diets. Principal component analysis indicated a correlation between Cu and As concentrations in liver and carcass weight, and between Zn and Cd liver levels and lean meat percentage. The linear discriminant analysis succeeded in predicting the farming process on the basis of the lean meat percentage and the liver Cd level.

We report the first halogen speciation analysis study by high performance liquid chromatography coupled with inductively coupled plasma tandem mass spectrometry (HPLC-ICPMS/MS) in the fruiting bodies of various mushroom species. Non-targeted speciation analysis revealed the occurrence of dichloroacetic acid (DCAA) in the edible mushroom Russula nigricans. Multiple samples of this mushroom (n = 5) collected from different geographic non-industrial regions in two different countries confirmed the consistent presence of this species at a relatively narrow concentration range (23–37 mg kg−1), whereas no other chlorinated acetic acid (e.g. chloroacetic acid and trichloroacetic acid) was detected. Neither DCAA nor any other chlorinated acetic acid were detected in any of the other mushroom species investigated in the present study, including seven different mushroom species of the same genus Russula, even though all mushrooms were collected from the same non-industrial geographic regions. Together with the previously reported biological activities of DCAA, these findings collectively suggest biosynthesis of this compound as an explanation for its dominant presence in R. nigricans, and constitute the first example of the dominant natural occurrence of this compound over other chlorinated acetic acids in a living organism. This may warrant a change in our view of the occurrence of dichloroacetic acid in nature, where primarily considered as a pollutant arising from water disinfection. Version of record

Protocols for solution nebulization (SN) multi collector (MC) ICP-MS analysis of the Hf isotopic composition of accessory minerals (zircon and baddeleyite) selected for high-precision ID-TIMS U\Pb geochronology have improved significantly during the last two decades. Precise crystallization age and Hf isotopic composition from the exact same volume of mineral can be retrieved, provided that time-consuming sample preparation and purification is possible. The present work focuses on the analytical capabilities of SN-MC-ICP-MS for Hf isotope analysis on non-purified reference materials. Analytical issues arise for (i) igneous and metamorphic zircons, often enriched in trace elements and REEs, which increase the amount of isobaric interferences. (ii) Small minerals that challenge the limits of quantification of the apparatus. JMC475 Hf standard, Plešovice and Temora-2 zircons and Phalaborwa baddeleyite were used to characterize the sources of analytical bias and to set up an optimized protocol for Hf isotope analysis of small accessory minerals with accurate correction of the isobaric interferences and accounting for the matrix effects. Doping of JMC475 with major (Zr, Si), trace (U, Th, Y, Ti) and rare earth elements (Ce, Nd, Gd, Dy, Ho, Er) shows that oxide species produced in the ICP induce an offset of the measured 176Hf/177Hf ratios that is corrected by normalization to the reference value. The 176Yb isobaric interference is efficiently removed for samples with Yb/Hf ratios b0.6 using in-run determined 176Yb/173Yb reference ratios from Yb doped reference material. This isotopic ratio varies (i) with time and (ii) sample matrix. Plasma loading by Zr is not the source of these variations. We propose that Yb oxidation in the plasma torch is responsible for variations in the 176Yb/173Yb ratio. Our dataset shows that matrix matched standards should be preferred for data reduction, and that Plešovice is a good zircon standard because of its availability, quantifiable REEs composition and potential forwide range of Yb doping. Consequently, lowHf concentration solutions fromTemora-2 zirconswere accurately measured in a small sample volume (b120 μl), using a short acquisition protocol (50 × 1 s cycles), and sample-standard bracketing for mass bias coefficient determination in a [Hf]~10 ng/g Plešovice solution measured through 80 × 4 s cycles. The repeatability of the measurement (2SD) is improved by factors of up to ~4.4 and the limit of quantification is brought down to b2 ng/g Hf, corresponding to zircon minerals of b24 ng.

Analytical and Bioanalytical Chemistry, 401 (9), ISSN:1618-2650, ISSN:1618-2642

A large variety of analytical methods are available to characterize particles in aerosols and suspensions. The choice of the appropriate technique depends on the properties to be determined. In many fields information about particle size and chemical composition are of great importance. While in aerosol techniques particle size distributions of gas-borne particles are determined online, their elemental composition is commonly analyzed offline after an appropriate sampling and preparation procedure. To obtain both types of information online and simultaneously, a hyphenated setup was recently developed, including a Scanning Mobility Particle Sizer (SMPS) and an Inductively Coupled Plasma Mass Spectrometer (ICPMS). This allows first to classify the particles with respect to their mobility diameter, and then to determine their number concentration and elemental composition in parallel. A Rotating Disk Diluter (RDD) is used as the introduction system, giving more flexibility regarding the use of different aerosol sources. In this work, a practical guide is provided describing the different steps for establishing this instrumentation, and how to use this analysis tool. The versatility of this hyphenated technique is demonstrated in example measurements on three different aerosols generated out of a) a salt solution, b) a suspension, and c) emitted by a thermal process., Journal of Visualized Experiments. JoVE (125), ISSN:1940-087X

Chronic high-exposure to arsenic (As) is associated with noncancerous and cancerous health effects (skin lesions, diabetes mellitus, degenerative effects on the circulatory system, neurotoxicity, cancer: liver, skin, bladder, kidneys, prostate and lungs). In Eastern Croatia, As geographically rich, As concentrations in official drinking water are still much higher than 10 µg/L (WHO, EU), with also wells massively used for gardening/drinking. As-species can be measured in the urine, but correlation with genetic damage and cancer risk demands time, invasive methods (e.g. blood) and cell culture. Since most of the cancers are of epithelial origin, buccal micronucleus cytome assay may be a potential new noninvasive biomarker of As- exposure and cancer risk before cancers development. We examined urine As- concentrations and As-species (organic: dimethylarsinic acid-DMA, monomethylarsonic acid-MA ; inorganic ; and the sum of cationic arsenic species) in 105 individuals using liquid chromatography coupled to inductively coupled plasma mass spectrometry-ICPMS and correlated the results with life style and drinking water habits, development of different diseases and parameters of buccal micronucleus cytome assay. The results demonstrated higher concentrations (mean±standard deviation, µg/L) of total As(33±33), DMA(18±13), MA(4.4±3.9) and inorganic As(4.1±3.3) ; higher frequency of micronucleated, binucleated and apoptotic cells ; with individual As concentrations above 100 µg/L, although the mean As value did not exceed the permitted levels. Matched control from Zagreb (continental part with uncontaminated drinking water) demonstrated low As concentrations in urine.

Human exposure to elements is a process difficult to control and monitor. Studies on this topic usually rely on single spot urine sample to assess exposure, with the risk of ignoring variability over a longer period. In this work, we measured the urinary excretion of toxic and essential elements during 1 year with the overall goal of exploring the variability caused by seasonality on their concentration. Seven participants were recruited, and first morning urines were collected three times for each season, during November, January, April and July. Participants followed the same balanced diet during the week of collection. We then monitored nineteen essential and toxic elements in urines by inductively coupled plasma mass spectrometry. Unsupervised multivariate statistical analysis separated samples collected during summer from the ones collected during other seasons. Twelve elements had a significant seasonal variation (ANOVA test, p

Inductively coupled plasma mass spectrometry is increasingly used for non-traditional applications such as the analysis of solids at high spatial resolution when combined with laser ablation or the analysis of engineered nanoparticles. This report highlights recent projects and discusses the potentials and limitations these techniques offer. High-resolution laser ablation instrumentation allows element imaging at the ?m-scale and can, therefore, be applied to, e.g., the mapping of metal isotope-labeled antibodies in biological tissues. Despite these advancements, the quantitative analysis of laser-produced aerosols is still a major concern. Here, the accuracy of analysis was found to strongly depend on particle size distribution but also on the morphology and composition of particles. In order to achieve a controlled supply of nanoparticles for analysis by inductively coupled plasma mass spectrometry, a dedicated microdroplet injection system was developed and characterized. This system allows a reproducible injection of single nanoparticles together with internal standards to determine their mass and composition.

In compliance with the European law (EC No. 510/2006), geographical indications and designations of origin for agricultural products and foodstuffs must be protected against mislabelling. This is particularly important for PDO hard cheeses, as Parmigiano Reggiano, that can cost up to the double of the no-PDO competitors. This paper presents two statistical models, based on isotopic and elemental composition, able to trace the origin of cheese also in grated and shredded forms, for which it is not possible to check the logo fire-marked on the rind. One model is able to predict the origin of seven types of European hard cheeses (in a validation step, 236 samples out of 240 are correctly recognised) and the other specifically to discriminate the PDO Parmigiano Reggiano cheese from 9 European and 2 extra-European imitators (260 out of 264 correct classifications). Both models are based on Random Forests. The most significant variables for cheese traceability common in both models are δ(13)C, δ(2)H, δ(15)N, δ(34)S and Sr, Cu, Mo, Re, Na, U, Bi, Ni, Fe, Mn, Ga, Se, and Li. These variables are linked not only to geography, but also to cow diet and cheese making processes.

Strontium and barium incorporation into otoliths was compared between whitemouth croaker, Micropogonias furnieri, collected from an entrapped freshwater population (Mirim Lagoon) and a normal marine/estuarine population in southern Brazil. Chemical analysis was performed using LA-ICPMS with the objective of validating the effects of marine and freshwater environments on Sr and Ba incorporation as a basis for further investigation of marine and freshwater connectivity of M. furnieri. The freshwater population was dominated by older fish with mean ±SD age of 34±1 y, whereas the coastal samples were dominated by younger fish of 14±7 y. Comparison of strontium and barium incorporation among otolith life-history profiles indicated significantly higher barium and lower strontium for the freshwater population compared to the marine population. Furthermore, comparison of otolith material deposited in the freshwater, estuarine and marine life-history phases demonstrated clear differences among these environments. Mean concentrations of strontium and barium in otoliths of M. furnieri were respectively 710 and 112 µg g-1 for freshwater, 2069 and 16.7 µg g-1 for estuarine, and 2990 and 2.7 µg g-1 for marine life-history phases. Barium concentrations in otoliths from the freshwater population of M. furnieri appeared high relative to other freshwater species. Strontium levels across life-history profiles of marine fish increased with age from 2000 to 2900 µg g-1, possibly indicating more time spent in marine than estuarine waters with age. In contrast, for the freshwater population, strontium levels decreased during the first year of life approximately to 700 µg g-1, and remained low and stable thereafter, consistent with the early life-history occurring in an estuarine environment prior to entrapment in Mirim Lagoon. The results confirm the strong and opposite effects of marine and freshwater environments on incorporation of barium and strontium into otoliths, and indicate that the population of M. furnieri in Mirim Lagoon represents an isolated population that does not reproduce and is therefore likely to become extinct. Estrôncio e bário foram determinados em otólitos de corvina Micropogonias furnieri coletados em habitats de água doce (lagoa Mirim) e costeiros no Sul Brasil. As análises foram realizadas utilizando-se LA-ICPMS, com o objetivo de estabelecer assinaturas químicas específicas para os diferentes habitats e avaliar a aplicabilidade da química de otólitos para o estudo de mudanças de habitat na espécie em questão para futuros estudos sobre conectividade de populações. Os animais coletados na lagoa Mirim apresentaram idade média de 34±1 anos, não sendo observados adultos jovens ou juvenis. Foi verificada uma variação significativa nas concentrações de Sr e Ba em otólitos para áreas marinhas e de água doce. Para ambientes marinhos, a idade média foi de 14±7 anos. Os valores médios de Sr e Ba foram estimados, respectivamente, em 710 e 112 µg g-1 para água doce, 2069 e 16,7 µg g-1 para água estuarina e 2990 e 2,7 µg g-1 para águas costeiras. Nos otólitos provenientes dos indivíduos de água doce, o Ba apresentou concentrações mais altas quando comparado a valores observados para outras espécies. Observou-se que a incorporação de Ba nos otólitos ao longo da vida sofre certa influência ontogenética, com valores mais altos medidos no início da vida. As concentrações de Sr em otólitos de animais costeiros aumentaram em média de 2000 a 2900 µg g-1 ao longo da vida, indicando a mudança de habitats estuarinos para marinhos. Para água doce, a concentração de Sr decresce antes do primeiro ano até valores em torno de 700 µg g-1 mantendo essa concentração por toda a vida, indicando um ambiente de água doce estável. Estes resultados confirmam o forte efeito inverso que ambientes marinhos e de água doce promovem na incorporação de Sr e Ba em otólitos e permitem sugerir que a corvina encontrada na lagoa Mirim é representada por um grupo isolado de animais com baixa probabilidade de reprodução que, portanto, será possivelmente extinto nos próximos anos.

This study investigated the body copper accumulation in the amphipod Gammarus sp.. Groups of copper-binding proteins were also investigated considering their molecular weights. Regarding copper accumulation, a saturation type kinetics was observed with Km and Vmax values of 0.48 mg Cu.L–1 and 713.3 μg Cu.g–1 dw, respectively. Size exclusion chromatography (5 to 150 KDa) associated with ICP-MS showed that most of copper-binding proteins in Gammarus sp. have molecular weights

We describe trends in fast, high resolution elemental imaging by laser ablation–inductively coupled plasma mass spectrometry (LA–ICPMS). Recently developed low dispersion LA cells deliver quantitative transport of ablated aerosols within 10 ms and also provide enhanced sensitivity compared to conventional LA cells because the analyte ion signal becomes less diluted during aerosol transport. When connected to simultaneous ICPMS instruments, these low dispersion LA cells offer a platform for high speed and high lateral resolution shot-resolved LA–ICPMS imaging. Here, we examine the current paradigms of LA–ICPMS imaging and discuss how newly developed LA cell technology combined with simultaneous ICPMS instrumentation is poised to overcome current instrumental limitations to deliver faster, higher resolution elemental imaging., Analytical and Bioanalytical Chemistry, 408 (11), ISSN:1618-2650, ISSN:1618-2642

Trace metals have negative effects on the oxidative stability of edible oils and they are important because of possibility for oils characterisation. A single-step procedure for trace elemental analysis of edible oils is presented. To this aim, a solubilisation with tetramethylammonium hydroxide (TMAH) was assayed prior to inductively coupled plasma mass spectrometry detection. Small amounts of TMAH were used, resulting in high elemental concentrations. This method was applied to edible oils commercially available in Argentine. Elements present in small amounts (Cu, Ge, Mn, Mo, Ni, Sb, Sr, Ti, and V) were determined in olive, corn, almond and sunflower oils. The limits of detection were between 0.004 μg g−1 for Mn and Sr, and 0.32 μg g−1 for Sb. Principal components analysis was used to correlate the content of trace metals with the type of oils. The two first principal components retained 91.6% of the variability of the system. This is a relatively simple and safe procedure, and could be an attractive alternative for quality control, traceability and routine analysis of edible oils. Fil: Savio, Marianela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; Argentina Fil: Ortiz, María S.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; Argentina Fil: Almeida, César Américo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; Argentina Fil: Olsina, Roberto Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; Argentina Fil: Martinez, Luis Dante. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; Argentina Fil: Gil, Raul Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; Argentina

In this study a novel method to determine iodine concentrations in human breast milk was developed andvalidated. The iodine was analyzed by inductively coupled plasma mass spectrometry (ICPMS) followingtetramethylammonium hydroxide (TMAH) extraction at 90◦C in disposable polypropylene tubes. Whilesimilar approaches have been used previously, this method adopted a shorter extraction time (1 h vs. 3 h)and used antimony (Sb) as the internal standard, which exhibited greater stability in breast milk and milkpowder matrices compared to tellurium (Te). Method validation included: defining iodine linearity up to200 g L−1; confirming recovery of iodine from NIST 1549 milk powder. A recovery of 94-98% was alsoachieved for the NIST 1549 milk powder and human breast milk samples spiked with sodium iodide andthyroxine (T4) solutions. The method quantitation limit (MQL) for human breast milk was 1.6 g L−1. Theintra-assay and inter-assay coefficient of variation for the breast milk samples and NIST powder were

International audience; Cr, Co, Cu, Zn, Cd and Pb in the bottom sediments from 93 sites at Quiberon bay were analyzed by Inductively Coupled Plasma Mass Spectrometry (ICPMS) after acid extraction. The ranges of the concentration in the sediments are as follows: 27.3 µg/g (Cr), 11.6 µg/g (Co), 13.8 µg/g (Cu), 42.0 µg/g (Zn), 0.08 µg/g (Cd) and 17.8 µg/g (Pb). Potential contamination of the bay was assessed by Igeo and pollution load index whether the concentration observed represent background or contaminated levels. Based on the results, it can be concluded that the bay is unpolluted for the studied metals.

The analysis of engineered nanomaterials (ENMs), especially engineered nanoparticles (ENPs), is a fast growing analytical research field. New trends in plasma spectrometry such as direct single particle inductively coupled plasma mass spectrometry (spICPMS) or the coupling of asymmetric flow field flow fractionation to ICPMS (A4F-ICPMS) allow direct analysis of ENPs by getting not only chemical but also size information simultaneously. However, sample handling of nanoparticles could be challenging and change the ENP properties. For most of the analysing techniques, dilution of ENP samples is needed as minimum sample preparation. The colloidal stability and the agglomeration behaviour depend on the ENP-type, the coating or functionalization agent and on the surrounding media. The stability of charge stabilized ENPs is especially sensitive to changes of pH or ionic strength, and sometimes even to dilution. Although the stability of sterically stabilized ENPs is typically less affected by the above-mentioned factors, agglomeration can still occur in certain environments. Thus, storage, handling and sample preparation are big challenges in ENP analysis. Kinetic studies of different ENPs, representative of typical nanoparticle types and coatings, point out that the behaviour is dependent on various influencing factors pertaining to the chemical environment (pH, ionic strength, dilution). In this study polyvinyl alcohol (Ag@PVA) and citrate (Ag@citrate) stabilized silver nanoparticles, as well as titanium oxide ENPs functionalized with poly-acrylate (TiO2@PA) have been studied. A simple analytical approach using batch dynamic light scattering (DLS) is proposed for a fast assessment of samples containing unknown ENP types or structures. Besides aspects of sample handling, unwanted particle–membrane interactions, which often lead to inappropriate recovery rates in A4F fractionation, are investigated here. These interactions are caused by the electrostatic charges carried by different membrane materials and the resulting interaction with the ENPs' charge. This is critically discussed for membrane materials typical for A4F analysis: polyethersulfone (PES), regenerated cellulose (RC), and polyvinylidene difluoride (PVDF).

Analytical and Bioanalytical Chemistry, 399 (6), ISSN:1618-2650, ISSN:1618-2642

The investigation was aimed at defining the compositional and structural characteristics of a group of monochrome blue faiences recovered in Pompeii to assess provenance on the basis of their technological features. Different complementary analytical techniques were used: Scanning Electron Microscopy (SEM) to investigate the morphological aspects of the samples and in particular of the interfaces, micro-Raman Spectroscopy and XRPD to identify crystalline phases and Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) to assess the elemental composition due to its sensitivity to a wide range of elements and the adequate lateral resolution. Statistical data treatment of the elemental concentrations of both the ceramic bodies and the glazes allowed us to classify the objects into compositional groups and to verify the previously established archaeological hypothesis suggesting an Egyptian provenance for faience of Pompeii.

International audience; A 2D high repetition rate femtosecond laser ablation strategy (2-mm wide lane) previously developed for the detection of selenoproteins in gel electrophoresis by inductively coupled plasma mass spectrometry was found to increase signal sensitivity by a factor of 40 compared to conventional nanosecond ablation (0.12-mm wide lane) [G. Ballihaut, F. Claverie, C. Pécheyran, S. Mounicou, R. Grimaud and R. Lobinski, Sensitive Detection of Selenoproteins in Gel Electrophoresis by High Repetition Rate Femtosecond Laser Ablation-Inductively Coupled Plasma Mass Spectrometry, Anal. Chem. 79 (2007) 6874-6880]. Such improvement couldn't be explained solely by the difference of amount of material ablated, and then, was attributed to the aerosol properties. In order to validate this hypothesis, the characterization of the aerosol produced by nanosecond and high repetition rate femtosecond laser ablation of polyacrylamide gels was investigated. Our 2D high repetition rate femtosecond laser ablation strategy of 2-mm wide lane was found to produce aerosols of similar particle size distribution compared to nanosecond laser ablation of 0.12-mm wide lane, with 38% mass of particles \textless 1 μm. However, at high repetition rate, when the ablated surface was reduced, the particle size distribution was shifted toward thinner particle diameter (up to 77% for a 0.12-mm wide lane at 285 μm depth). Meanwhile, scanning electron microscopy was employed to visualize the morphology of the aerosol. In the case of larger ablation, the fine particles ejected from the sample were found to form agglomerates due to higher ablation rate and then higher collision probability. Additionally, investigations of the plasma temperature changes during the ablation demonstrated that the introduction of such amount of polyacrylamide gel particles had very limited impact on the ICP source (ΔT~ 25 ± 5 K). This suggests that the cohesion forces between the thin particles composing these large aggregates were weak enough to have negligible impact on the ICPMS detection. © 2009 Elsevier B.V. All rights reserved.

Ni and V have been determined in snow and ice collected at a high altitude location (Col du Dôme) near the summit of Mont Blanc on the French-Italian border; dated from the 1960s and 1990s. Ni and V were simultaneously determined by inductively coupled plasma sector field mass spectrometry. Measured concentrations range from 6 to 700 pg g(-1) and 4 to 1,100 pg g(-1) for Ni and V, respectively. The results show pronounced seasonal variations in the concentrations of both metals, with high concentration values in summer layers and much lower values for winter layers. These seasonal variations are linked especially with the existence of inversion layers during winter months. Ni and V concentrations in excess of the contributions from rock and soil dust (Ni(excess), V(excess)) appear to be mainly associated with anthropogenic inputs, with pronounced seasonal variations. Large variations in the V(excess)/Ni(excess) ratio are observed, with a higher ratio in summer than in winter. This shows differences in anthropogenic inputs at Col du Dôme during the different parts of the year. The above ratio was compared with the corresponding ratios for oil combustion from stationary sources and the exhaust from gasoline and diesel engines. It appears that Ni and V concentrations at Col du Dôme are probably the result of changing combinations of contributions from oil combustion for power generation, industrial and residential uses, on one side, and automobile and truck traffic, on the other side, with possibly a significant contribution from Ni smelters in Russia during winter months.