Concentrations Of Multiple Elements Research Articles

Potential of Otolith Microchemistry to Distinguish Nursery Areas of Salmon within River Simojoki

Draining into the northern Baltic Sea, River Simojoki is an important spawning river for Atlantic salmon. The present study aimed to preliminary explore the potential of analysing the elemental composition of otoliths to distinguish the within-river nursery area of origin for salmon. Parr were sampled at three nursery areas in the river and smolts of unknown origin were sampled near the river mouth during the migration to the sea. The concentrations of multiple elements and the strontium 87Sr/86Sr isotopic ratio in the otoliths were analysed using single- and multi-collector laser ablation inductively coupled plasma mass spectrometry, respectively. Based on the otolith elemental variables, parr could be reclassified to the sampled nursery areas using discriminant function analysis and random forest with a success rate of 53.3% and 63.3%, respectively. However, for parr sampled at the uppermost nursery area in the river, the success rates were 90% and 100%, respectively. Applying the classification models trained on the parr samples to determine which nursery area sampled smolt originated from was constrained by the limited sampling of parr, both in sample sizes and the coverage of the nursery areas found in the river.

Post-deposition hydrothermal alteration and U-Pb isotopic resetting of wolframite in the Tiantangshan deposit, Nanling Range (South China): Implications for complex isotopic ages of ore deposits

Tiantangshan deposit in the southeastern Nanling Range is a newly discovered Rb-Sn-W polymetallic deposit. In this paper, we present in-situ U-Pb isotope and major and trace element analyses of wolframite from the Tiantangshan deposit to examine the possible post-deposition hydrothermal alteration and U-Pb isotopic resetting of wolframite, with additional insight into possible genesis of variably young mineralization ages in the Nanling Range. Wolframite in the W ore body (wolframite-cassiterite quartz veins) of the Tiantangshan deposit comprises two stages, i.e., Wolf I and Wolf II. The primary Wolf I occurs as euhedral crystals with oscillatory growth bands, and is rich in Fe relative to Mn, with Mn/(Mn + Fe) ratios varying from 0.15 to 0.26. The Wolf I yielded U-Pb age of 133.7 ± 1.8 Ma (2σ; MSWD = 0.6). The Wolf II crosscuts and occurs as rims of the Wolf I with irregular boundaries, which has higher Mn and lower Fe contents than the Wolf I, with Mn/(Mn + Fe) ratios varying from 0.43 to 0.88. It shows similar REE pattern and concentrations of multiple elements (e.g., Sc, Ti, V, Zr, Hf and In) with the Wolf I, and also correlates with the Wolf I for elemental ratios of Nb vs. Ta, Zr vs. Hf, Nb + Ta vs. WO3 and Sn vs. WO3. These features suggest that the Wolf II was formed by replacing the Wolf I. The Wolf II yielded U-Pb age of 95.4 ± 1.3 Ma (2σ; MSWD = 0.8). Collectively, the U-Pb age of Wolf I (∼134 Ma) represents the W mineralization age in the Tiantangshan deposit, whereas, the age of the Wolf II (∼95 Ma) does not represent a second stage of W mineralization, but isotopic resetting during post-deposition hydrothermal alteration of the Wolf I. The fluids accounting for the Wolf II was likely sourced from granites of the Late Cretaceous episode (∼96 Ma) outcropping in adjacent areas. Our results indicate that wolframite and its U-Pb isotope system is susceptible to post-deposition hydrothermal alteration. This study also implies that later magmatism and hydrothermal fluids may result in isotopic resetting and the variably young ages in the Nanling Range. Therefore, interpretation of ages obtained from a hydrothermal ore deposit should be based on detailed macroscopic to microscopic observation and multiple isotopic ages of different minerals, and particularly, abnormal young ages need to be treated with caution.

Essential and Non-essential Trace Elements in Milks and Plant-Based Drinks

Although milk and plant-based drinks are widely consumed foodstuffs with high nutritional value, their consumption may also mean intake of non-essential/toxic elements becoming a risk for human health. This study was aimed at determining the concentrations of essential (Ca, Co, K, Mg, Mn, Na, Ni and P) and non-essential/toxic (Hg, Pb, U and V) elements in milks (cow and goat), plant-based drinks (soy, almond, rice and oat) and infant formulas from organic and conventional production systems. Lactose-free, fresh and ultra-high-temperature (UHT) milks were also included. Chemical analyses were performed by means of inductively coupled plasma-mass spectrometry (ICP-MS). The content of the elements hereby assessed did not depend on the production system and the presence of lactose. However, significant differences were found in the concentrations of multiple elements when comparing sterilization methods, source (animal vs. plant-based) and animal species. Non-essential elements were not detected in milks and plant-based drinks, excepting Pb, which was detected in three samples. While the consumption of goat milk is recommended, considering the global intake of essential elements and the absence of non-essential elements, further studies should be conducted to confirm the absence of non-target toxic elements at very low trace levels. On the other hand, the best plant-based drinks are those made up with almonds (intake of Ca) and soy (K and Mg). The current results should be useful to help the population to balance the benefits and risks from milks and plant-based drinks consumption, as well as to adapt their dietary habits.

Identification of goat milk powder by manufacturer using multiple chemical parameters

Concentrations of multiple elements and ratios of stable isotopes of carbon and nitrogen were measured and combined to create a chemical fingerprint of production batches of goat whole milk powder (WMP) produced by different manufacturers. Our objectives were to determine whether or not differences exist in the chemical fingerprint among samples of goat WMP produced at different sites, and assess temporal changes in the chemical fingerprint in product manufactured at one site. In total, 58 samples of goat WMP were analyzed by inductively coupled plasma-mass spectrometry as well as isotope ratio mass spectrometry and a suite of 13 elements (Li, Na, Mg, K, Ca, Mn, Cu, Zn, Rb, Sr, Mo, Cs, and Ba), δ13C, and δ15N selected to create the chemical fingerprint. Differences in the chemical fingerprint of samples between sites and over time were assessed using principal components analysis and canonical analysis of principal coordinates. Differences in the chemical fingerprints of samples between production sites provided a classification success rate (leave-one-out classification) of 98.1%, providing a basis for using the approach to test the authenticity of product manufactured at a site. Within one site, the chemical fingerprint of samples produced at the beginning of the production season differed from those produced in the middle and late season, driven predominantly by lower concentrations of Na, Mg, K, Mn, and Rb, and higher concentrations of Ba and Cu. This observed temporal variability highlights the importance of obtaining samples from throughout the season to ensure a representative chemical fingerprint is obtained for goat WMP from a single manufacturing site. The reconstitution and spray drying of samples from one manufacturer by the other manufacturer enabled the relative influence of the manufacturing process on the chemical fingerprint to be examined. It was found that such reprocessing altered the chemical fingerprint, although the degree of alteration varied among samples and individual elements. The findings of this study support the use of trace elements and stable isotope ratios to test the authenticity of goat WMP, which can likely be applied to other dairy goat products. This approach could be used test to the factory of origin (and potentially batch of origin) of products in the supply chain, thus providing the ability to audit the supply chain and monitor for fraudulent activity.