Exploring a low-cost turbidimetric sensor for available potassium determination in soil.

Potassium (K) is among the macronutrients required for crop production and it is absorbed through plant roots from the soil solution. Replenishment of soil K is usually done by fertilizer application; therefore, it is crucial to know the amount of this nutrient that's available in the soil. There's very little literature reporting a turbidimetric method for K determination, and even less in soil samples.

Waterborne metal levels in four freshwater lakes from Harmony Point, Nelson Island, Antarctica.

The aim of this study is to analyze the waterborne metal levels in four lakes (one endorheic and three exorheic) of Harmony Point, Nelson Island, Antarctica. Water samples were analyzed by using a quadrupole type inductively coupled plasma mass spectrometer and an inductively coupled plasma optical emission spectrometer. The levels of As, Cu, Mn, Mo, and V were significantly lower and those of Cr, Mg, Na, and Sr were significantly higher in the endorheic lake than in the other lakes.

A miniaturized flow batch chemical vapor generation system for Hg determination in fish by ICP-MS.

A new flow batch (FB) system for chemical vapor generation (CVG) is proposed for mercury (Hg) determination in fish. An inductively coupled plasma mass spectrometer was used as a detector. Low-cost peristaltic mini pumps were used to propel the solutions and different configurations of FB systems (reactor/gas/liquid separator) were studied.

Toxicity of copper and zinc alone and in combination in Caenorhabditis elegans model of Huntington's disease and protective effects of rutin.

Copper (Cu) and Zinc (Zn) are required in small concentrations for metabolic functions, but are also toxic. There is a great concern about soil pollution by heavy metals, which may exposure the population to these toxicants, either by inhalation of dust or exposure to toxicants through ingestion of food derived from contaminated soils. In addition, the toxicity of metals in combination is questionable, as soil quality guidelines only assess them separately.

Effects of LaO nanoparticles and bulk-LaO on the development of Pfaffia glomerata (Spreng.) Pedersen and respective nutrient element concentration.

Nanoparticles (NPs) have been progressively applied in the last decades, which may impact the environment. Synthesis of pigments, growing, and nutrient element uptake by plants can also be affected by NPs. The influence of lanthanum oxide nanoparticles (LaO NPs) on growth, pigment synthesis, and nutrient element uptake by Pfaffia glomerata (Spreng.

Habitat use and nursery evaluation for the longnose stingray Hypanus guttatus (Bloch & Schneider, 1801) using vertebral microchemistry.

Here, we use vertebral microchemistry to investigate the habitat use patterns of the longnose stingray Hypanus guttatus in the northern and northeastern regions of Brazil, and to evaluate the existence of potential nurseries of the species. Samples were collected in Maranhão, Rio Grande do Norte and Pernambuco states between 2008 and 2019. Trace element concentrations of Ba:Ca, Mg:Ca, Mn:Ca and Sr:Ca in vertebrae were determined through laser ablation inductively coupled plasma mass spectrometry.

Plants' genetic variation approach applied to zinc contamination: secondary metabolites and enzymes of the antioxidant system in Pfaffia glomerata accessions.

Zinc (Zn) is a micronutrient, but its excessive concentration can impair plant growth and development. Fertilizers, liming materials, pesticides and fungicides containing Zn have contributed to increase its concentration in agricultural soils. The aim of the present study is to evaluate the effect of Zn excess on the non-enzymatic (anthocyanin and β-ecdysone) and enzymatic (superoxide dismutase-SOD and guaiacol peroxidase-GPX) antioxidant system of two P.

Investigative Analysis of Lanthanum Oxide Nanoparticles on Elements in Bone of Wistar Rats After 30 Days of Repeated Oral Administration.

Accumulation of lanthanum oxide nanoparticles (LaONPs) in the femur bone of rats after 30 days of oral administration was explored. Also, the influence of LaONPs on macro and trace elements in the rats' femur bone was assessed. Inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma optical spectrometry (ICP OES) were used for total element determination in the bone after decomposition while laser ablation-ICP-MS (LA-ICP-MS) was used to investigate element distribution (bio-imaging) in the bone.

LaO Nanoparticles: Study of Uptake and Distribution in (Spreng.) Pedersen by LA-ICP-MS and μ-XRF.

The production and use of nanoparticles (NPs) in different fields increased in the last years. However, some NPs have toxicological properties, making these materials potential emerging pollutants. Therefore, it is important to investigate the uptake, transformation, translocation, and deposition of NPs in plants.

Arsenic speciation analysis in rice milk using LC-ICP-MS.

The consumption of rice milk has increased, mainly by individuals intolerant to lactose or allergic to cow milk. However, rice milk contains As. In this sense, the concentration of As in rice milk should be controlled.

In vitro stability of arsenic trioxide-liposome encapsulates for acute promyelocytic leukemia treatment.

In this work, we investigated the stability of arsenic trioxide (ATO) used in leukemia treatment, encapsulated with nanoliposome, with the aid of ultrasound treatment. Stability studies of As species were followed by liquid chromatography-inductively coupled plasma mass spectrometry (LC-ICP-MS), allowing for the detection of the conversion of low amounts of As(III) to As(V) or the formation of other As species. The influence of storage temperature and time on ATO was evaluated.

Combined exposure to methylmercury and manganese during L1 larval stage causes motor dysfunction, cholinergic and monoaminergic up-regulation and oxidative stress in L4 Caenorhabditis elegans.

Humans are exposed simultaneously to a variety of neurotoxic agents, including manganese (Mn) and methylmercury (MeHg). Therefore, the study of combined exposures to toxicants is timely. This work aimed to study changes in cholinergic system focusing on acetylcholinesterase (ace-2), monoaminergic system focusing on vesicular monoamine transporter (VMAT, cat-1) expression, to address changes in antioxidant enzymatic systems, namely, the expression of superoxide dismutase (sod-3 and sod-4) and catalase (ctl-3), as well as worm reproduction and locomotion.

Bioimaging Metallomics.

This chapter focuses on bioimaging in metallomics, which involves metal and metalloids distribution in animal tissues. It starts with laser ablation-inductively coupled plasma-mass spectrometry followed by secondary ion mass spectrometry, synchrotron-based X-ray fluorescence, and electron microscopy, including transmission electron microscopy, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The basic principles of these techniques and their application for qualitative and quantitative imaging of elements are presented.

Feasibility of Rare Earth Element Determination in Low Concentration in Crude Oil: Direct Sampling Electrothermal Vaporization-Inductively Coupled Plasma Mass Spectrometry.

A comprehensive study was developed showing the feasibility of determination of rare earth elements (REE) in low concentration in crude oil by using direct sampling electrothermal vaporization system coupled to inductively coupled plasma mass spectrometry (ETV-ICP-MS). The effect of organic modifier on the REE signal was evaluated and the use of 6 mg of citric acid allowed calibration using aqueous reference solutions (selected pyrolysis and vaporization temperatures were 700 and 2200 °C, respectively). Because of the facility of REE in forming refractory compounds inside the graphite furnace during the heating step, the use of a modifier gas (Freon R-12, 3.

Selenium and silicon reduce cadmium uptake and mitigate cadmium toxicity in Pfaffia glomerata (Spreng.) Pedersen plants by activation antioxidant enzyme system.

Cadmium (Cd) is toxic to plants and animals, making it necessary to develop strategies that seek to reduce its introduction into food chains. Thus, the aim of this study was to investigate whether silicon (Si) and selenium (Se) reduce Cd concentrations in Pfaffia glomerata medicinal plant and attenuate the oxidative stress promoted by this metal. These plants were cultivated in hydroponics under the following treatments: control (nutrient solution), 2.

Rare earth elements profile in a cultivated and non-cultivated soil determined by laser ablation-inductively coupled plasma mass spectrometry.

Rare earth elements (REEs) have several applications but the effects on environment are not well known. Therefore, the aim of this work is to establish a method for direct solid sample analysis by laser ablation-inductively coupled plasma mass spectrometry (LA-ICP-MS) to evaluate the concentration and distribution of REEs in cultivated and non-cultivated soil. Samples were collected in two areas to 40 cm of depth.

A new approach to calibration and determination of selected trace elements in food contact polymers by LA-ICP-MS.

A calibration strategy using porous nylon disks and reference solutions is proposed for the first time for matrix matching and determination of As, Ba, Cd, Cr, Pb, Sr and Zn in polymers by laser ablation-inductively coupled plasma mass spectrometry (LA-ICP-MS). Polymer samples commonly used in contact with food were analyzed. The procedure consists on the use of porous nylon disks as support for a dried droplet reference solution.

Triphenyltin hydroxide induces changes in the oxidative stress parameters of fish.

Among all organotin compounds , triphenyltin hydroxide (TPhTH) is widely used as fungicide and moluscicide in Brazil. However, the effects of TPhTH on the biochemical parameters of non-target organisms, such as fish, are little known. The aim of the present study is to assess the possible toxic effects of different concentrations of waterborne TPhTH on silver catfish belonging to species Rhamdia quelen.

Selenium and mercury levels in rat liver slices co-treated with diphenyl diselenide and methylmercury.

Organoseleno-compounds have been investigated for its beneficial effects against methylmercury toxicity. In this way, diphenyl diselenide (PhSe)2 was demonstrated to decrease Hg accumulation in mice, protect against MeHg-induced mitochondrial dysfunction, and protect against the overall toxicity of this metal. In the present study we aimed to investigate if co-treatment with (PhSe)2 and MeHg could decrease accumulation of Hg in liver slices of rats.

External calibration strategy for trace element quantification in botanical samples by LA-ICP-MS using filter paper.

The use of reference solutions dispersed on filter paper discs is proposed for the first time as an external calibration strategy for matrix matching and determination of As, Cd, Co, Cr, Cu, Mn, Ni, Pb, Sr, V and Zn in plants by laser ablation-inductively coupled plasma mass spectrometry (LA-ICP-MS). The procedure is based on the use of filter paper discs as support for aqueous reference solutions, which are further evaporated, resulting in solid standards with concentrations up to 250 μg g(-1) of each element. The use of filter paper for calibration is proposed as matrix matched standards due to the similarities of this material with botanical samples, regarding to carbon concentration and its distribution through both matrices.

Toxic and nutrient elements in yerba mate (Ilex paraguariensis).

Toxic and nutrient elements were investigated in yerba mate (Ilex paraguariensis) from South America. Fifty-four brands of commercialised yerba mate from Argentina, Brazil, Paraguay and Uruguay were analysed for Al, Ba, Ca, Cu, Fe, K, Mg, Mn, P, Sr, and Zn, using inductively coupled plasma optical emission spectrometry (ICP-OES), and Li, Be, Ti, V, Cr, Ni, Co, As, Se, Rb, Mo, Ag, Cd, Sb, La, Ce, Pb, Bi and U using inductively coupled plasma mass spectrometry (ICP-MS). Antimony, Se, Ag and Bi were not detected in any sample whereas the limits of detection (LODs) of these elements were 0.

Imazethapyr and imazapic, bispyribac-sodium and penoxsulam: zooplankton and dissipation in subtropical rice paddy water.

Herbicides are very effective at eliminating weed and are largely used in rice paddy around the world, playing a fundamental role in maximizing yield. Therefore, considering the flooded environment of rice paddies, it is necessary to understand the side effects on non-target species. Field experiment studies were carried out during two rice growing seasons in order to address how the commonly-used herbicides imazethapyr and imazapic, bispyribac-sodium and penoxsulam, used at recommended dosage, affect water quality and the non-target zooplankton community using outdoor rice field microcosm set-up.

Feasibility of low frequency ultrasound for water removal from crude oil emulsions.

The feasibility of indirect application of low frequency ultrasound for demulsification of crude oil was investigated without using chemical demulsifiers. Experiments were performed in an ultrasonic bath with frequency of 35 kHz. Synthetic emulsions with water content of 12%, 35% and 50% and median of droplet size distribution (DSD), median D(0.

Histopathological biomarkers in juvenile silver catfish (Rhamdia quelen) exposed to a sublethal lead concentration.

The aim of this study was to determine the 96-h lethal concentration (96-h LC50) of lead (Pb) in silver catfish, Rhamdia quelen, and to determine histopathological biomarkers in fish exposed for 96-h to a sublethal concentration at 25% of the LC50. The 96-h LC50 was 108 mgl(-1). In gills, the length and thickness of lamella and thickness of the filament epithelium were significantly higher in fish exposed to Pb for 48-h than in control fish whereas the interlamellar distance decreased.