The casts of Pompeii bear witness to the people who died during the Vesuvius 79 AD eruption. However, studies on the cause of death of these victims have not been conclusive. A previous important ...step is the understanding of the post-depositional processes and the impact of the plaster in bones, two issues that have not been previously evaluated. Here we report on the anthropological and the first chemical data obtained from the study of six casts from Porta Nola area and one from Terme Suburbane. A non-invasive chemical analysis by portable X-ray fluorescence was employed for the first time on these casts of Pompeii to determine the elemental composition of the bones and the plaster. Elemental profiles were determined providing important data that cross-referenced with anthropological and stratigraphic results, are clearly helpful in the reconstruction of the perimortem and post-mortem events concerning the history of these individuals. The comparative analyses carried out on the bone casts and other collections from burned bones of the necropolis of Porta Nola in Pompeii and Rome Sepolcreto Ostiense, and buried bones from Valencia (Spain), reveal the extent of high temperature alteration and post-depositional plaster contamination. These factors make bioarchaeological analyses difficult but still allow us to support asphyxia as the likely cause of death.
The use of additives, including dyes, is common in the preparation of food products. The analytical control of artificial food dye content is relevant since some, such as azo dyes, may produce cancer ...and attention deficit disorders and hyperactivity in children. Consequently, the maximum permitted concentration of azo dyes in food is regulated by current legislation. Therefore, it is of interest to find simple and fast procedures for the control of these compounds. The aim of this study is to determine the concentration of azo dyes in food samples by the Arata-Possetto method - based on the extraction of azo dyes employing natural wool -, followed by the analysis of an image captured by a smartphone camera. After experimentally determining the optimal extraction conditions, the calibration curves for standard solutions of different food dyes and the color of the dyed wool were obtained. Results from dyed wool image processing were compared with the absorbance spectra of the solutions before extraction as measured by a diode array spectrophotometer. The spectrophotometric and the image processing procedures were employed to obtain the calibration curves for different food dyes, which were subsequently employed to analyze food samples. Statistical treatment shows that the results of both methods are comparable.
In this article, the Islamic gold coins collections of the University of Valencia is studied for the first time for its elemental composition and colorimetric properties. To that end, non-destructive ...elemental analysis using energy-dispersive X-ray fluorescence is applied to obtain the coins' elemental profile. Additionally, the colour of the coins is assessed using smartphone-based colorimetry as an innovative non-invasive method. Results indicate that the Islamic coins could be attributed to Almoravids, and the gold origin could be the famous Sudanese gold, an ore which was valued all over the world. Also, the text found in the coins was translated and allowed to objectively identify the mint and year. Based on these results, it can be seen that the earliest coins struck in the Iberian Peninsula are characterised by slightly lower gold concentrations than the ones struck in the northern part of Africa, pointing towards a potential recycling of coins which already circulated in the area. In conclusion, this work provides new analytical insights into a peculiar and unique type of samples, allowing to draw some conclusions in terms of their origins and materials, and for the first time allows to characterise the chromatic coordinates of this type of samples.
A cheap and easy to use Arduino self-assembled automatic system was employed to continuously monitor the hydrogen peroxide consumption during the photo-Fenton degradation of caffeine, selected as ...model target compound. The automatic system made it possible to measure the H2O2 concentration in the reaction cell via a colorimetric reaction and to take samples for HPLC analysis minimising the operator manual intervention and exposure to UV radiation. The obtained results were compared in terms of LOD and LOQ with H2O2 measurements manually performed using UV–Vis spectrophotometry, evidencing better analytical performance when using the automatic system; LOD and LOQ were respectively 0.032 mM and 0.106 mM for the automatic system against 0.064 mM and 0.213 mM for UV–Vis spectrophotometry. Furthermore, the photo-Fenton treatment was optimised by means of a Design of Experiments (DoE) investigating the effect of added H2O2 concentration, iron concentration and caffeine initial concentration on system performances. The use of the automatic device for such monitoring provided several advantages: automation (with consequent reduction of the workload), measurement increased precision, reduced reagents consumption and waste production in agreement with the principles of Green Analytical Chemistry.
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•An automatic system enabled H2O2 quantification & minimized manual intervention.•The automatic measurement showed lower LOD & LOQ than the traditional method.•DoE combined with automatic device allows photo-Fenton treatment optimization.•New device offers automation, precision, reduced workload & operator exposure.•Study showcases automatic devices potential in laboratory analyses.
Water pollution by heavy metal ions has become a serious environmental issue especially due to their toxicity and tendency to bioaccumulation. Natural smectite clay was treated using sulfuric acid to ...improve its adsorption capacity for the removal of iron ions from aqueous solutions. The results showed that adsorption was favored at pH 3 and room temperature. The experimental adsorption capacity of Fe(III) is 12.86 and 19.25 mg/g for natural and acid-activated clay, respectively. From all of our data, we conclude that the treated clay by sulfuric acid investigated in this study showed good potential for iron removal from aqueous solutions.
A cold vapor atomic fluorescence spectrometry method (CV-AFS) has been developed for the determination of Hg in rice samples at a few ng
g
−1 concentration level. The method is based on the previous ...digestion of samples in a microwave oven with HNO
3 and H
2O
2 followed by dilution with water containing KBr/KBrO
3 and hydroxylamine and reduction with SnCl
2 in HCl using external calibration. The matrix interferences and the effect of nitrogen oxide vapors have been evaluated and the method validated using a certified reference material. The limit of detection of the method was 0.9
ng
g
−1 with a recovery percentage of 95
±
4% at an added concentration of 5
ng
g
−1. The concentration level of Hg found in 24 natural rice samples from different origin ranged between 1.3 and 7.8
ng
g
−1.
•Multivariate calibration models to predict Ca, K, Mg, Fe, Mn and Zn in artichokes were developed.•NIR and XRF spectra were used to generate calibration models.•XRF and NIR are an alternative to ...classical analysis of mineral elements in foods.
Near infrared (NIR) and X-ray fluorescence (XRF) spectroscopy were investigated to predict the concentration of calcium, potassium, iron, magnesium, manganese and zinc in artichoke samples. Sixty artichokes were purchased from different Spanish areas (Benicarló, Valencia and Murcia). NIR and XRF spectra, combined with partial least squares (PLS) data treatment, were used to develop chemometric models for the prediction of mineral concentration. To obtain reference data, samples were mineralised and analysed by inductively coupled plasma optical emission spectrometry (ICP-OES). Coefficients of determination obtained for the regression between predicted values and reference ones for calcium, potassium, magnesium, iron, manganese and zinc were 0.61, 0.79, 0.53, 0.77, 0.54 and 0.60 for NIR and 0.96, 0.93, 0.80, 0.79, 0.76 and 0.90 for XRF, respectively. Both assayed methodologies, offer green alternatives to classical mineral analysis, but XRF provided the best results in order to be used as a quantitative screening method.
•Mineral profile of baby foods compared with values found in the literature.•The 35 baby foods analysed are generally adequate for essential mineral intake.•Ca, Fe and Zn levels are very low to baby ...recommended daily intake.•Low levels of potentially toxic elements were found.
Commercial baby foods are an important part of the daily intake of babies from 6 to 12months. The mineral profile of commercial baby foods in Spain was determined to establish levels of essential and non-essential elements, and their contribution to adequate intake (AI) and estimated average requirement (EAR). Thirty-five jars of commercial foods containing meat, fish, vegetables and fruit were obtained from the Spanish market and the mineral composition determined for 14 elements. In general, the baby foods analysed were sufficient for an adequate mineral intake, but contributions to AI and EAR for iron, zinc and calcium were very low (5–20%, 10–60% and 10–70%, respectively). This deficiency could be associated with growth problems or diseases in adulthood, and fortification of commercial products is recommended.
•Kaki fruit samples produced in Spain are generally adequate for essential elements.•Low levels of potentially toxic elements were found.•Consume of one pieces per day of kaki fruit involves ...appropriate mineral intake.•Mineral profile of kaki fruit samples compared with values found in the literature.
The main objective of this study was the determination of the mineral profile of 167 kaki fruit (Diospyros kaki L.) samples produced from different regions of Spain, including samples with the protected designation of origin (PDO) ‘Kaki Ribera del Xúquer’ Valencia (Spain). Samples were analysed by inductively coupled plasma optical emission spectroscopy (ICP-OES) and inductively coupled plasma mass spectrometry (ICP-MS). Consumption of one piece of kaki fruit (200–400g) would give a mineral intake providing 1–10% of the recommended daily allowance (RDA) for calcium, 1–30% for copper and potassium, 1–15% from iron and magnesium, up to 1% of sodium, and up to 4% of zinc. ANOVA analysis indicates differences between samples from different Spanish region, thus offering a way for authentication of PDO sample origin.
•Tuna samples were adulterated with NaNO2 and NaNO3, as well as vegetable extracts.•HPLC-DAD was applied to quantify the amount of NaNO2 and NaNO3 in the samples.•Colorimetric analysis was made using ...a smartphone and a spectroradiometer.•Beetroot and nitrite were the most effective treatments, maintaining red colour.•Colour allows to objectively discriminate between adulteration methods.
In this work, a colorimetric analysis of adulterated tuna samples is carried out using both a spectroradiometer and a smartphone as capture devices. Yellowfin tuna (Thunnus albacares) slices were treated with nitrate and nitrite salts, as well as with two different vegetable extracts (beetroot and radish), and the resulting NO2– and NO3– concentration was analysed using HPLC-DAD. The results indicate that both nitrite and beetroot treatments work properly as colouring agents in tuna, being nitrate also effective. When assessing the effect of radish, the final flesh had a more whitish colour. Overall, this approach allows to obtain colorimetric data which can distinguish among the different adulterating agents.
