Elemental Imaging of Fertilized ZnO NP Wheat Endosperms Using Laser Ablation-Inductively Coupled Plasma Optical Emission Spectrometry

Zinc (Zn) is an essential trace element in the human body, and its deficiency can seriously affect health. Agronomic Zn biofortification with ZnO nanoparticles (ZnO NPs) in consumable wheat prospectively relieves Zn deficiency. We developed an elemental quantitative imaging laser ablation-inductively coupled plasma optical emission spectrometry method to examine the distributions of Zn and other micronutrient elements in wheat grain and the endosperm. After foliar application of ZnO NPs (four rounds), Zn content in the endosperm can be significantly increased (221 ± 61%), and the Zn, Ca, Mg, and P content gradient decreased from the outside seed coat and aleurone layer to the endosperm, whereas the Fe, Mn, K, Cu, Sr, and Ba content gradient decreased from the crease region to the deeper endosperm. This may indicate how different elements enter the endosperm. Foliar application of ZnO NPs did not change the micronutrient accumulation pattern but did change their contents in wheat grain.

Gadolinium retention in the tunica media of arterial walls - a complementary study using elemental bioimaging and immunogold staining

Gadolinium (Gd) deposition has been found in both animal and human tissues after serial injections of gadolinium-based contrast agents (GBCAs). Without the knowledge of which tissues are most affected, it is difficult to determine whether Gd accumulation could lead to any pathological changes. The current study aims at investigating histological sections of three patients who were exposed to GBCAs during their lifetime, and identify areas of Gd accumulation. Tissue sections of three autopsy cases were investigated by laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) to assess the distribution of Gd, and the deposition within tissue sections was quantified. Additional application of laser ablation-inductively coupled plasma-optical emission spectroscopy (LA-ICP-OES) enabled a sensitive detection of calcium (Ca) in the vessel walls, which is usually impeded in LA-ICP-MS due to the isobaric interference with argon. Complementary LA-ICP-MS and LA-ICP-OES analysis revealed that Gd was co-localized with zinc and calcium, in the area where smooth muscle actin was present. Notably, high levels of Gd were found in the tunica media of arterial walls, which requires further research into potential Gd-related toxicity in this specific location.

Laser-Ablation Sampling for Accurate Analysis of Sulfur in Edible Salts

We evaluated the performance of laser ablation analysis techniques such as laser-induced breakdown spectroscopy (LIBS), laser ablation inductively coupled optical emission spectrometry (LA-ICP-OES), and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), in comparison with that of ICP-OES using aqueous solutions for the quantification of sulfur (S) in edible salts from different geographical origins. We found that the laser ablation based sampling techniques were not influenced by loss of S, which was observed in ICP-OES with aqueous solutions for a certain salt upon their dissolution in aqueous solutions, originating from the formation of volatile species and precipitates upon their dilution in water. Although detection of S using direct laser sampling with LA-ICP-MS has well-known isobaric and polyatomic interferences, LIBS and LA-ICP-OES showed good accuracy in the detection of S for all salts. LIBS also provided the ability to identify the dominant chemical form in which S is present in salts. Correlation between S and oxygen, observed in LIBS spectra, provided chemical information about the presence of S^2- or [Formula: see text], which are associated with the origin and quality of edible salts.