106 research outputs found
Liquid Chromatography/Mass Spectrometry in Environmental Analysis
No full textLiquid chromatography-mass spectrometry (LC-MS) has expanded the analytical framework for the analysis of polar organic contaminants in complex matrices primarily through advances in high-resolution mass spectrometry, ion mobility spectrometry, evolving repository databases, and data mining software.
Over the last 10 years, the analytical trends toward a comprehensive characterization of emerging environmental contaminants along with their degradation and transformation products have driven the move from target analysis of few tens of compounds to wide-scope target screening, as well as the development of strategies aimed at suspect screening of ‘known unknowns’ and the more challenging nontarget analysis for the identification of ‘unknown unknowns’. In this context, there is also an urgent need to give objective and unambiguous evidence of the confidence level of identification from a large list of tentatively identified substances, as well as to automate the evaluation process toward a more reproducible and harmonized approach.
This article represents a third edition of a previous manuscript by Mattarozzi and Careri,(1) which was updated to take into account the huge progress in MS instrumentation and related methodologies and also advances in environmental analytical chemistry. In this article, among the environmental applications of LC-MS, current and innovative approaches for the analysis of selected classes of emerging pollutants, such as micro- and nanoplastics, per- and poly-fluoroalkyl substances, and transformation products in environmental samples are discussed, attempting to have a global coverage on the most recent research studies regarding the development of methodologies for the contaminants of high concern for the environment
Liquid Chromatography/Mass Spectrometry in Environmental Analysis
No full textLiquid chromatography/mass spectrometry (LC-MS) technique enables analysis of emergent polar compounds without the need for derivatization reaction, while the introduction of high-resolution mass analyzers in hybrid configurations makes possible to elucidate chemical structure, also without reference standards. Over the past 10 years, besides target analysis, the coupling of LC to high-resolution mass spectrometry (HRMS) has allowed screening of compounds expected to be in the environment, as well as nontarget screening of unknown compounds, such as transformation products (TPs) formed in the environment or during technical wastewater and sewage purification treatments. Nowadays, analytical chemists are trying to achieve real nontarget analysis of numerous unknowns in environmental samples for a comprehensive view of the true overall contamination present in samples, but it still remains a very challenging issue. The development of new software tools to extract relevant data, spectra libraries, and databases will be of great help to solve this issue, enhancing the success rate.
This article represents the second edition of a previous manuscript by Careri,2000 which was updated to take into account the huge progress in MS instrumentation and related methodologies and also advances in environmental analytical chemistry. In this overview, among the environmental applications of LC-MS, current and innovative approaches for the analysis of selected classes of emerging pollutants, such as novel brominated flame retardants, nanomaterials, hormones and other endocrine disruptors, and pharmaceutical and personal care products in environmental samples are discussed
The role of incurred materials in method development and validation to account for food processing effects in food allergen analysis
No full textThe issue of undeclared allergens represents a matter of great concern, being the subject of many alert notifications by the Rapid Alert System for Food and Feed portal of the European Commission, often leading to food recalls. The availability of reliable analytical approaches able to detect and quantify hidden allergens in processed foods is increasingly requested by the food industry, food safety authorities and regulatory bodies to protect sensitive consumers’ health. The present review discusses the fundamental role of incurred materials for method development and analytical performance assessment in a metrology perspective on testing for undeclared allergens in processed foodstuffs. Due to the nature of the analytes and their susceptibility to various processing effects, reliability and comparability of results have posed a great challenge. In this context, the use of incurred samples as reference materials permits simulation of the effects of food processing on target analyte structure affecting analyte extractability and detectability
Innovative gold-free carbon nanotube/chitosan-based competitive immunosensor for determination of HIV-related p24 capsid protein in serum
No full textIn the past decade, the need for simple, rapid, sensitive, specific and inexpensive screening methods for diagnosis of HIV infection has led to a focus on the HIV1-related capsid protein p24. In this work, the first competitive electrochemical immunosensor for the detection of p24 in untreated human serum was developed as a simple, easy-to-use and promising tool for serum screening for early diagnosis of HIV infection. The immunodevice was implemented on disposable gold-free single-walled carbon nanotube-functionalized screen-printed electrodes. The competitive sensor is based on the immobilization of the target protein on the electrode surface using a chitosan/glutaraldehyde crosslinking system, able to ensure, under mild conditions, a robust immobilization and a proper exposition of p24 for interaction with a mouse anti-p24 IgG1. The immunosensor setup as well as the assay's experimental conditions were then optimized, achieving a wide linear detection range of 10 pM to 1 nM, with a low detection limit of 2 pM in human serum. The good performance, also in terms of selectivity, trueness and precision, coupled with the advantages of an easy preparation compared to other methods requiring very complex conjugation procedures between bioreceptors and expensive nanostructures, makes the immunosensor a powerful diagnostic tool, valuable for implementation of large-scale screening programs for early diagnosis of seropositivity
The role of surface in desorption electrospray ionization-mass spectrometry: advances and future trends
No full textAn outlook on the current status and trends in desorption electrospray ionization-mass spectrometry (DESI-MS), one of the most
common spray-based techniques for ambient ionization, is given with a focus on the main advances recently achieved or still in
progress regarding studies of surface properties affecting the signal stability and efficiency of the DESI process. Future directions
that the field may take in the years to come are discussed, with particular focus on bioanalytical research
Electrochemical immunomagnetic assay as biosensing strategy for determination of ovarian cancer antigen HE4 in human serum
No full textPrompt cancer diagnosis and treatment represent fundamental aspects to significantly improve patient survival rate. Human epididymis protein 4 (HE4) has recently been identified as promising single serum biomarker of epithelial ovarian cancer with improved diagnostic performances respect to current reference biomarkers. In this study we present the first competitive immunosensing strategy for HE4 determination implemented on magnetic microbeads functionalized with HE4 antigen. A full factorial design and multiple linear regression allowed to find the optimal experimental conditions providing the maximum inhibition rate within the explored domain. Method validation was performed in serum to ensure reliable data to support decision in clinical practice. This method allowed matching the clinically relevant concentration values for the serum biomarker, limits of detection and
quantification being 2.8 and 23.0 pM, respectively. Also recovery rate in the 89±7 -103±5 % range resulted suitable for method applicability for diagnostic purposes
Competitive amperometric immunosensor for determination of p53 protein in urine with carbon nanotubes/gold nanoparticles screen-printed electrodes: A potential rapid and noninvasive screening tool for early diagnosis of urinary tract carcinoma
No full textSince p53 protein has become recognized biomarker for both diagnostic and therapeutic purposes in oncological diseases with particular relevance for bladder cancer, it is highly desirable to search for a novel sensing tool for detecting the patient's p53 level at the early stage. Here we report the first study on the development and validation of a novel disposable competitive amperometric immunosensor for determination of p53 protein at subnanomolar levels, based on p53 immobilization on gold nanoparticles/carbon nanotubes modified screen-printed carbon electrodes. The assay protocol requires the use of single anti-p53 mouse monoclonal antibody (DO-7 clone), able to recognize both wild-type and mutant p53. The developed immunosensor as well as the protocol of the electrochemical immunoassay were optimized by means of an experimental design procedure to assess the suitability of the device to be validated and applied for the determination of p53 in untreated and undiluted urine samples. It was found that the developed competitive immunodevice was able to achieve wide linear range detection of wild-type p53 from 20 pM to 10 nM with a low detection limit of 14 pM in synthetic urine samples, suggesting the sensor's capability of working in a complex sample matrix. The excellent performance results also in terms of selectivity, trueness and precision, coupled with the advantages of an easy preparation and low-cost assay in contrast to other methods which require very complex, time-consuming and costly nanostructured architectures, makes the developed competitive immunosensor an analytically robust diagnostic tool, valuable for implementation of screening and follow-up programs in patients with urologic malignancies
Characterization of the volatile profile of thistle honey using headspace solid-phasemicroextraction and gas chromatography–mass spectrometry
No full textAn innovative method based on quick, easy, cheap, effective, rugged, and safe extraction coupled to desorption electrospray ionization-high resolution mass spectrometry for screening the presence of paralytic shellfish toxins in clams
No full textThe capabilities of desorption electrospray ionization-high resolution mass spectrometry (DESI-HRMS)
were tested for screening the presence of some paralytic shellfish toxins in clams. A quick, easy, cheap,
effective, rugged, and safe (QuEChERS) approach is proposed for sample clean-up.QuEChERS extraction
was optimized by using a full factorial design followed by the multicriteria method of the desirability
functions. Quantitation limits in the microgram pe rkilogram range proved reliability of the method for
the detection of the investigated toxins in accordance to the rules laid down by European legislation. The
optimized QuEChERS-DESI-HRMS based-method allowed for a rapid reliable screening of the in-
vestigated compounds at levels of interest, thus being useful for high-throughput analyse
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