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

2021 ◽  
Vol 17 (34) ◽  
pp. 153-169
Author(s):  
Maria Fernanda Sarmiento-Gamero ◽  
Carlos Daniel Ramos-Contreras ◽  
Sofía Lorena Flórez-Pérez ◽  
Francisco José Molina-Pérez
Keyword(s):  
Sustainable Development ◽  
Particulate Matter ◽  
Reference Material ◽  
Limit Of Detection ◽  
Urban Dust ◽  
Acid Digestion ◽  
Microwave Assisted ◽  
Linear Behavior ◽  
Coefficients Of Variation ◽  
Detection And Quantification

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.

scholarly journals Analysis and determination of secondary organic aerosol (SOA) tracers (markers) in particulate matter standard reference material (SRM 1649b, urban dust)

2019 ◽  
Vol 411 (23) ◽  
pp. 5975-5983 ◽  
Author(s):  
Alexandre Albinet ◽  
Grazia Maria Lanzafame ◽  
Deepchandra Srivastava ◽  
Nicolas Bonnaire ◽  
Frederica Nalin ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Reference Material ◽  
Standard Reference Material ◽  
Secondary Organic Aerosol ◽  
Organic Aerosol ◽  
Urban Dust

Micro-Extraction of Commonly Abused Benzodiazepines for Urinary Screening by Liquid Chromatography

1997 ◽  
Vol 34 (1) ◽  
pp. 61-67 ◽  
Author(s):  
Kim Wolff ◽  
Deborah Garretty ◽  
Alastair W M Hay
Keyword(s):  
Liquid Chromatography ◽  
Coefficient Of Variation ◽  
Limit Of Detection ◽  
Extraction Procedure ◽  
Sample Processing ◽  
Sample Handling ◽  
Urinary Screening ◽  
Low Concentrations ◽  
Coefficients Of Variation ◽  
Detection And Quantification

We have developed a micro-extraction procedure for the analysis of seven commonly prescribed benzodiazepines (chlordiazepoxide, diazepam, lorazepam, nitrazepam, nordiazepam, oxazepam, and temazepam) in urine using liquid chromatography. The method is reliable and sensitive, uses small volumes (100μL) of urine and is suitable for the detection and quantification of low concentrations of benzodiazepines. The micro-extraction procedure allowed rapid sample processing, which is important for routine sample handling. The limit of detection for the seven benzodiazepines ranged from 0·10–0·71 mg/L and recovery of the different benzodiazepines was good, ranging from 70–105%. Between-and within-assay coefficients of variation ranged from 6·3% to 13·8%, and 2% to 3·5%, respectively. Chlordiazepoxide chromatographed poorly (between assay coefficient of variation 35·4%, within-assay 7%), and we set the cut-off value for this compound at 5·0 mg/L.

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

Metals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1935
Author(s):  
Jonovan Van Yken ◽  
Ka Yu Cheng ◽  
Naomi J. Boxall ◽  
Chris Sheedy ◽  
Aleksandar N. Nikoloski ◽  
...  
Keyword(s):  
Reference Material ◽  
Analytical Methods ◽  
Printed Circuit Boards ◽  
Electronic Waste ◽  
Circuit Boards ◽  
Icp Oes ◽  
Acid Digestion ◽  
Printed Circuit ◽  
Microwave Assisted ◽  
Value Recovery

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.

scholarly journals SaQuant: a real-time PCR assay for quantitative assessment of Staphylococcus aureus

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Colin Wood ◽  
Jason Sahl ◽  
Sara Maltinsky ◽  
Briana Coyne ◽  
Benjamin Russakoff ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Sensitivity And Specificity ◽  
Pathogen Detection ◽  
Limit Of Detection ◽  
Future Research ◽  
Limit Of Quantification ◽  
Pathogen Prevalence ◽  
Single Well ◽  
Effective Public Health ◽  
Detection And Quantification

Abstract Background Molecular assays are important tools for pathogen detection but need to be periodically re-evaluated with the discovery of additional genetic diversity that may cause assays to exclude target taxa or include non-target taxa. A single well-developed assay can find broad application across research, clinical, and industrial settings. Pathogen prevalence within a population is estimated using such assays and accurate results are critical for formulating effective public health policies and guiding future research. A variety of assays for the detection of Staphylococcus aureus are currently available. The utility of commercial assays for research is limited, given proprietary signatures and lack of transparent validation. Results In silico testing of existing peer-reviewed assays show that most suffer from a lack of sensitivity and specificity. We found no assays that were specifically designed and validated for quantitative use. Here we present a qPCR assay, SaQuant, for the detection and quantification of S. aureus as might be collected on sampling swabs. Sensitivity and specificity of the assay was 95.6 and 99.9 %, respectively, with a limit of detection of between 3 and 5 genome equivalents and a limit of quantification of 8.27 genome equivalents. The presence of DNA from non-target species likely to be found in a swab sample, did not impact qualitative or quantitative abilities of the assay. Conclusions This assay has the potential to serve as a valuable tool for the accurate detection and quantification of S. aureus collected from human body sites in order to better understand the dynamics of prevalence and transmission in community settings.

scholarly journals The Ionic Associate of Metamizole as an Electrode-Active Component of a PVC Plasticized Membrane Electrode

Chemosensors ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 17
Author(s):  
Sarizhat D. Tataeva ◽  
Kurban E. Magomedov ◽  
Ruslan Z. Zeynalov ◽  
Naida D. Baygishieva ◽  
Viktorya S. Magomedova ◽  
...  
Keyword(s):  
Active Component ◽  
Limit Of Detection ◽  
Membrane Electrode ◽  
Ionic Associate ◽  
Selective Electrode ◽  
Coefficients Of Variation ◽  
Ion Associate ◽  
Phase Functions ◽  
Good Agreement

The technology for manufacturing a film membrane of the metamizole-selective electrode containing ion associate metamizole-octadecylammonium ODAH+MT− as an electrode active component (EAC) has been proposed. The main potentiometric characteristics of the metamizole-selective electrode have been determined. The expediency of the proposed design of the metamizole selective electrode for the determination of metamizole in dosage forms has been substantiated. The best composition of the membrane (wt.%) of the metamizole-selective electrode has corresponded to: ODAH+MT−—5.3; 2-nitrophenyloctylether—63.1; poly(vinyl chloride)—31.6. Electrode-active component in the membrane phase functions as an ion associate ODAH+MT−. Potentiometric characteristics of metamizole-selective electrode have been determined, which corresponded to: linear range 1 × 10−2–1 × 10−4 with limit of detection 4.58 × 10−5 M, electrode function slope −48.5 mV/dec., working interval pH 4.5–7.3, response time 60 s. The potentiometric coefficients of selectivity of the metamizole-selective electrode with respect to various ions have been determined. The possibility of determining metamizole in a medicinal product has been tested. The results of the analyses show good agreement between the two methods (relative error less than 7.0%) with coefficients of variation less than 5% for MT-SE and iodometric methods.

scholarly journals Estimation of Cadmium Levels in Local Banana (Musa) Fruits by ICP-MS Technology-A Pan India Study

2020 ◽  
Vol 40 (01) ◽  
Author(s):  
Prachi Sinkar ◽  
Kallathi Kumar ◽  
Kajal Rai ◽  
Syam Praveen Kumar Jeepipalli
Keyword(s):  
Irrigation Water ◽  
Industrial Waste ◽  
Cadmium Accumulation ◽  
Acid Digestion ◽  
Chemical Fertilizers ◽  
Microwave Assisted ◽  
Imminent Danger ◽  
Icp Ms ◽  
Over Exploitation

Industrial waste discharging into the irrigation water is a major cadmium source for plants. Over exploitation of chemical fertilizers in the agriculture is also a growing concern of cadmium accumulation into the plant. Purpose of this study was evaluation of cadmium prevalence in locally available banana fruits across the country. Microwave assisted acid digestion was used to homogenize the banana samples with subsequent analysis by ICP-MS technology. Banana samples from 59 districts of India were analyzed. Among the 59 districts of India, The districts of Tiruchirapalli and Bahraich had having highest cadmium levels respectively, 0.51 - 0.6 ng/g, 0.81 - 0.9 ng/g. Least banana cadmium levels (0-0.19 ng/g) was observed in banana from 28 districts of India. Study concludes that, bio-magnification of cadmium is the imminent danger. Phyotoremediation is welcoming approach.

scholarly journals Total Fat Gravimetric Method Workflow in Portuguese Olives Using Closed-Vessel Microwave-Assisted Extraction (MAE)

Foods ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 2364
Author(s):  
João Gonçalo Lourenço ◽  
Daniel Ettlin ◽  
Inês Carrero Cardoso ◽  
Jesus M. Rodilla
Keyword(s):  
Limit Of Detection ◽  
Gravimetric Method ◽  
Reference Value ◽  
Microwave Assisted Extraction ◽  
Closed Vessel ◽  
Limit Of Quantification ◽  
Microwave Assisted ◽  
Assisted Extraction ◽  
Total Fat

A simple and rapid method for the quantitation of total fat in olive samples is designed, evaluated, and presented. This method is based on an innovative closed-vessel microwave-assisted extraction (MAE) technique. A method was designed for olives, and some figures of merits were evaluated: limit of detection (LOD), limit of quantification (LOQ) and expanded uncertainty (U). The data obtained in these experiences show that the workflow of the MAE method in a closed container is statistically equivalent to the other two methods, showing in this case better performance indicators (LOD = 0.02%, LOQ = 0.06%, and U = 15%). In addition, it is also demonstrated that the complete MAE method workflow allows the determination of total fat in a maximum of 12 analyses simultaneously for about 100 min in each run, which is the capacity of the rotor. This is a much better productivity when compared to the traditional Soxhlet-based method. Considering the sample workflow, the closed-vessel MAE method greatly simplifies sample handling, therefore minimizing sample loss during sample preparation and reducing analysis time. When MAE is compared to NIR-based methods, the advantage comes from there being no need for any type of calibration in the sample matrix. The MAE method itself can be used to determine the reference value for NIR calibration purposes. The results obtained for CRM using MAE were equivalent to the ones shown on the certificate.

Microwave-assisted diluted acid digestion for trace elements analysis of edible soybean products

2015 ◽  
Vol 175 ◽  
pp. 212-217 ◽  
Author(s):  
José Tiago P. Barbosa ◽  
Clarissa M.M. Santos ◽  
Vanessa N. Peralva ◽  
Erico M.M. Flores ◽  
Mauro Korn ◽  
...  
Keyword(s):  
Trace Elements ◽  
Acid Digestion ◽  
Microwave Assisted ◽  
Trace Elements Analysis

Micro-quantity tissue digestion for metal measurements by use of a microwave acid-digestion bomb.

1989 ◽  
Vol 35 (3) ◽  
pp. 488-490 ◽  
Author(s):  
J R Nicholson ◽  
M G Savory ◽  
J Savory ◽  
M R Wills
Keyword(s):  
Nitric Acid ◽  
Reference Material ◽  
Microwave Digestion ◽  
Absorption Spectrometry ◽  
Bovine Liver ◽  
Dry Weight ◽  
Acid Digestion ◽  
Tissue Samples ◽  
Dry Ashing ◽  
Tissue Digestion

Abstract We describe a simple and convenient method for processing small amounts of tissue samples for trace-metal measurements by atomic absorption spectrometry, by use of a modified Parr microwave digestion bomb. Digestion proceeds rapidly (less than or equal to 90 s) in a sealed Teflon-lined vessel that eliminates contamination or loss from volatilization. Small quantities of tissue (5-100 mg dry weight) are digested in high-purity nitric acid, yielding concentrations of analyte that can be measured directly without further sample manipulation. We analyzed National Institute of Standards and Technology bovine liver Standard Reference Material to verify the accuracy of the technique. We assessed the applicability of the technique to analysis for aluminum in bone by comparison with a dry ashing procedure.

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