An Inductively Coupled Plasma Optical Emission Spectrometric Method for the Determination of Toxic and Nutrient Metals in Spices after Pressure-Assisted Digestion

The aim of this study was to develop a simple and rapid inductively coupled plasma optical emission spectrometric (ICP-OES) method for the determination of 17 metals (Ag, Al, B, Ba, Bi, Ca, Cd, Co, Cr, Cu, Fe, Mg, Mn, Ni, Pb, Tl and Zn) in packaged spices. For this purpose, the spice samples (200 mg) in the form of powder were submitted to pressure-assisted wet-acid digestion with a mixture of 6 mL concentrated HNO3 and 1 mL H2O2. The proposed method was validated in terms of linearity, trueness, precision, limits of detection (LODs) and limits of quantification (LOQs). Good method trueness, precision and linearity were observed for the examined elements. The LODs of the examined analytes ranged between 0.08 and 5.95 mg kg−1. The present method was employed for the analysis of twenty-two packaged commercially available spices including asteroid anise, clove, cardamon, cinnamon, curry, coriander, turmeric, cumin, white pepper, black pepper, nutmeg, allspice, red pepper, paprika, ginger, green pepper and pink pepper from the Greek market that are widely consumed. A wide variety of metal of different concentration ranges were determined in the samples.

Assessment of Heavy Metal Residues in Excreta of Rock Pigeon (Columba Livia) and Domestic Pigeon (Columba livia Domestica) in Faisalabad, Punjab, Pakistan

Pollution is the main cause that effects the environment in a degradable condition. For the presence of heavy metals in the atmosphere birds are considered as tremendous bio indicator. Blue pigeon and domestic pigeon (Coloumba livia) of Faisalabad are selected to examine the level of heavy metals including Manganese (Mn), zinc (Zn), Cobalt (Co), lead (Pb) cadmium (Cd) and Copper (Cu) in several tissues such as (heart, lungs, bones, muscles and feathers. Six adult birds were collected rural, urban and residential and traffic areas of Faisalabad. After collection of sample fresh weight will be measured of each sample, then digestion of sample was done by conventional acid digestion method and digested samples were analyzed in the lab by Atomic Absorption Spectrophotometer for the determination of heavy metals. It was concluded that accumulation of heavy metals in the birds depends upon the environmental conditions. Our result showed that concentration of heavy metals more in rock pigeon as compared to domestic pigeon which may be due to more exposure of industrial waste to rock pigeon. It has inferred from our study that high concentration of heavy metals in the excreta of rock pigeon was due to its high trophic level in food chain.

Determination of Zn, Fe, Cr and Cu in Marine Fish Commonly Consumed in Senegal

The content of four heavy metals (zinc, iron, chromium and copper) in muscles, liver and gonads has been studied for the five most consumed fish species (Cephalopholus taeniops, Scomber japonicus, Lagocephalus laevigatus, Pagellus bellottii and Pagrus caeruleostictus) in the Soumbedioune region. The samples were digested by acid digestion. The metal contents were quantified using a PF-11 type photometer. The results obtained show that metals such as zinc, iron and chromium are significantly higher (p <0.05) in the muscles of the four species than in the liver and gonads. However, the levels of heavy metals in the muscles, liver, and gonads of the five species are above the acceptable limit recommended by the FAO and WHO, with the exception of the copper levels in the gonads of the species Pagellus bellottii.

Production and Characterization of Cellulose Nanofiber Slurries and Sheets for Biomedical Applications

Cellulose nanomaterials are produced employing a multitude of methodologies including electrospinning, bacterial generation, acid digestion, and a variety of mechanical defibrillation techniques; the morphology of the nanomaterial produced is specific to the production process. Feedstocks range from various forms of woody biomass, to fungi, and have a great impact on the resulting product. The mechanical defibrillation technique, such as that employed in the present work, continuously breaks down cellulose fibers suspended in water via segmentation and defibrillation through grinding and refining. The process is typically operated until a desired level of fines is achieved in the resultant slurry of cellulose nanofiber (CNF), alternatively known as cellulose nanofibril. Mechanical defibrillation processes can be built to produce several liters in a small batch system or up to tons per day in a continuous pilot scale refiner system. In the present work a continuous system was developed with the capacity to produce 14 L of cellulose nanofiber slurry with consistent specifications and in a manner compliant with GMP/GLP protocols in order to be amenable to biomedical applications. The system was constructed within an ISO class 7 cleanroom and refining was performed on bleached softwood pulp suspension in purified water. This manuscript details the continuous grinding system, the processes employed to produce cellulose nanofiber, and characterizes the resultant cellulose nanofiber slurry and sheets formed from the slurry.

A Comparison of Methods for the Characterisation of Waste-Printed Circuit Boards

Electronic waste is a growing waste stream globally. With 54.6 million tons generated in 2019 worldwide and with an estimated value of USD 57 billion, it is often referred to as an urban mine. Printed circuit boards (PCBs) are a major component of electronic waste and are increasingly considered as a secondary resource for value recovery due to their high precious and base metals content. PCBs are highly heterogeneous and can vary significantly in composition depending on the original function. Currently, there are no standard methods for the characterisation of PCBs that could provide information relevant to value recovery operations. In this study, two pre-treatments, smelting and ashing of PCB samples, were investigated to determine the effect on PCB characterisation. In addition, to determine the effect of particle size and element-specific effects on the characterisation of PCBs, samples were processed using four different analytical methods. These included multi-acid digestion followed by inductively coupled plasma optical emission spectrometry (ICP-OES) analysis, nitric acid digestion followed by X-ray fluorescence (XRF) analysis, multi-acid digestion followed by fusion digestion and analysis using ICP-OES, and microwave-assisted multi-acid digestion followed by ICP-OES analysis. In addition, a mixed-metal standard was created to serve as a reference material to determine the accuracy of the various analytical methods. Smelting and ashing were examined as potential pre-treatments before analytical characterisation. Smelting was found to reduce the accuracy of further analysis due to the volatilisation of some metal species at high temperatures. Ashing was found to be a viable pre-treatment. Of the four analytical methods, microwave-assisted multi-acid digestion offered the most precision and accuracy. It was found that the selection of analytical methods can significantly affect the accuracy of the observed metal content of PCBs, highlighting the need for a standardised method and the use of certified reference material.

The magnetic stir bar as a source of impurities in laboratory blank solutions of the environmental samples subjected to microwave-assisted acid digestion

Teflon-coated magnetic stir bars are suspected to be a source of impurities for the laboratory blank solutions. To evaluate the ability of magnetic bars to absorb and release different elements at sub-ppb and above-ppb (µg L-1) level the experiment with new and used bars was conducted. The bars were subjected to microwave-assisted acid digestion with the soil sample and a series of successive cleaning procedures. The ICP-OES/MS analysis of the obtained extracts revealed that most of the elements may be released during subsequent extractions in the ppb-level concentrations, whereas the following elements: Cr, Cu, Sb, Sn, and Pb may be extracted even in elevated concentrations. SEM/EDS inspection of Teflon surfaces demonstrated the multiple defects that probably increase the absorption of the elements. We concluded that the concentration of mineral impurities in the laboratory blank solution prepared in the randomly selected one vessel per sample preparation batch is hardly propagated to the other used vessels. The alternative concept "blank per vessel" was proposed especially for ultra-trace analysis. Also, an additional step in the bar washing procedure was proposed.

Determinación de metales pesados en material particulado atmosférico por espectroscopía de absorción atómica: validación

El análisis de Cr, Cd, Pb y Ni en material particulado (PM10) permite establecer los niveles de exposición y de cuantificación, empleando digestión ácida asistida por microondas y espectroscopía de absorción atómica. Se evaluaron los parámetros: linealidad, límite de detección y de cuantificación, precisión y veracidad. Se obtuvo comportamiento lineal (R2>0,995) entre 0,75-2,5 μgCd, 8,75-125 μgNi, 5-25 μgCr y 8,75-15 μgPb. También, se evidenció efecto matriz (α=0.05) en todos los metales estudiados. Los coeficientes de variación (0,9-12%) y los porcentajes de recuperación (66-126%) se encontraron dentro de los intervalos permitidos. El análisis del material de referencia (NIST 1649b Urban Dust) permitió determinar la veracidad de la metodología (71-102 % R). Por consiguiente, la metodología puede ser implementada para evaluar de manera confiable, el cumplimiento de la resolución 2254:2017 del Ministerio de Medio Ambiente y Desarrollo Sostenible. The analysis of Cr, Cd, Pb, and Ni in particulate matter (PM10) makes it possible to establish the levels of exposure and risk to the health of the population. This work presents the validation and implementation of analytical methodologies, using microwave-assisted acid digestion and atomic absorption spectroscopy. The parameters were evaluated: linearity, the limit of detection and quantification, precision, and veracity. Linear behavior (R2> 0.995) was obtained between 0.75-2.5 μg Cd, 8.75-125 μg Ni, 5-25 μg Cr and 8.75-15 μg Pb. Also, a matrix effect (α = 0.05) was evidenced in all the metals studied. The coefficients of variation (0.9-12%) and the recovery percentages (66-126%) were found within the allowed intervals. The analysis of the reference material (NIST 1649b Urban Dust) allowed to establish the veracity of the methodology (71-102 % R). Finally, the methodology can be implemented to reliably assess compliance with resolution 2254: 2017 of the Ministry of the Environment and Sustainable Development.

Study of Diatom Flora of Kaalesar Ghat of Rapti River at Gorakhpur for Forensic Consideration

Diatoms are unique algae. They are scientifically known as Bacillariophyceae. Diatoms have been used in forensic science in a variety of ways, the most frequent being the diagnosis of death by drowning. When a person drowns, water will enter the lungs and then enter the bloodstream through ruptures in the peripheral alveoli before being carried to the other organs such as the liver and heart. Naturally, the microscopic contents of the water, which will include diatoms, will pass into the blood as well. The detection of diatoms in the organs can contribute to a diagnosis of death by drowning, a process referred to as the ‘diatom test’. A study was conducted in the department of Forensic Science, SHUATS, Prayagraj which included the extraction and identification of diatoms from the collected water samples from three different sites of Kaalesar Ghat of Rapti River in Gorakhpur. The acid digestion method was used for diatom extraction. And, after analysis total 13 diatom species were found. The identified diatoms were of great ecological assessment that plays an important role in criminal investigations related to premortem or ante-mortem drowning. Keywords: Diatom, Drowning, D-mapping, Rapti-River

Evaluation of heavy metals content in the canned/packed fruit juices from local and imported origin in Lahore, Pakistan

This study was conducted to determine the mean concentration of heavy metals such as lead (Pb), copper (Cu), zinc (Zn), chromium (Cr), manganese (Mn), nickel (Ni), selenium (Se), magnesium (Mg), and iron (Fe) in canned/packed fruits juices, collected from various stores in Lahore in a period of three months. These juices were categorized into four groups; local packed and canned and also imported packed and canned products. Every group consisted of ten samples. By using the di-acid digestion method, the collected samples were digested and analyzed under Atomic Absorption Spectrophotometer (AAS). The results indicated that the mean values of 7 out of 9 tested heavy metals including Pb, Mg, Ni, Fe, Cr, Se and Mn were above permissible limits (set by WHO) in all four understudy groups. Therefore, it was concluded that commercially available fruit juices are not all safe according to their heavy metals content for the human consumption despite their nutritive values.