Detection Of Toxic Substances Research Articles

Detection of Acetone Using Surface Plasmon Resonance

Abstract: In most industries, detection of substances remains important as applications differ from the industry such as detections of materials for research, detection of toxic substances in liquids and more. There have been numerous ways of detection but few can only acquire data quickly and in real time such as SPR sensors. Surface Plasmon Resonance is an optical detection method that uses surface plasmons and spectroscopy that can only detect a particular substance. Using this technique can be applied for quick detection of substances which can help researchers and engineers to have a more solid precautionary equipment. For this project, the experimental setup has the characteristics of an SPR sensor; however the reflected light can be quickly transferred via fiber optic to a spectrometer and computer for instant results. To further elaborate and complement experimental data, simulations that show the dip of reflectivity of a certain angle at which is called resonance angle which can be done by using Lumerical.

Detection of terbufos in cases of intoxication by means of entomotoxicological analysis using ATR-FTIR spectroscopy combined with chemometrics

The detection of toxic substances in larvae from carcasses in an advanced stage of decomposition may help criminal expertise in elucidating the cause of death in suspected cases of poisoning. Terbufos (Counter®) or O,O-diethyl-S-[(tert-butylsulfanyl)methyl] phosphorodithioate is an insecticide and systemic nematicide, which has very high toxicity from an acute point of view (oral LD50 in rodents ranging from 1.4 to 9.2 mg/kg) that has been marketed irregularly and indiscriminately in Brazil as a rodenticide, often being used to practice homicides. The present study aims to evaluate the use of attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy to detect traces of terbufos pesticide in fly larvae (Sarcophagidae). ATR-FTIR spectra of scavenger fly larvae from control (n = 31) and intoxicated (n = 80) groups were collected and submitted to chemometric analysis by means of multivariate classification using principal component analysis with quadratic discriminant analysis (PCA-QDA), successive projections algorithm with quadratic discriminant analysis (SPA-QDA) and genetic algorithm with quadratic discriminant analysis (GA-QDA) in order to distinguish between control and intoxicated groups. All discriminant models showed sensitivity and specificity above 90%, with the GA-QDA model showing the best performance with 98.9% sensitivity and specificity. The proposed methodology proved to be sensitive and promising for the detection of terbufos in scavenger fly larvae from intoxicated rat carcasses. In addition, the non-destructive nature of the ATR-FTIR technique may be useful in preserving the forensic evidence, meeting the precepts of the chain of custody and allowing for counter-proof.

METHODOLOGICAL APPROACHES TO SCREENING OF NARCOTIC AND POTENT MEDICINES IN BIOLOGICAL OBJECTS

The society nowadays is being exposed to constant high toxicological stress. The expanding range of substances people use in their daily life, a growing drug addiction rate, newly developed highly active medicines, environmental and man-made disasters, the chemicals used to commit acts of terror, the progress of chemically-induced diseases – all these result in a steady increase in the number of poisoning cases. The detection of toxic substances in the body of someone who suffered poisoning is the leading area in diagnosing disease of chemical origin. Apart from clarifying the diagnosis, important is to identify the indications for hospitalization, the choice of the detoxification method, as well as that of the antidote therapy. Given that, chemical and toxicological studies aimed at the detection, identification, and quantification of a wide range of toxic substances in objects of biological origin are relevant and enjoy respective demand. This paper offers a comparative analysis of preliminary research methods, as well as extraction from internal organs, of biological fluids and physical evidence to be taken into account through chemical and toxicological analysis carried out to detect medicinal, narcotic substances and metabolites thereof. The research objects here were blood, urine, bile, internal organs, brain from human corpses of males and females, aged 21 to 65, with different causes of death, as well as physical evidence (residue of medicines). The results of this study can be used to select methods for detecting toxic substances at the stages of forensic chemical examination.

Construction of characterization parameters of algal photosynthetic inhibition method for detection of comprehensive toxicity in water

Pollutants in water seriously threaten the health of human beings and will lead to potential ecological risks to the aquatic environment. Researchers use many chemical, physiological and morphological methods to detect the comprehensive toxicity in water. Among them, the photosynthetic inhibition method is considered a powerful method to detect the comprehensive toxicity in water, takes the chlorophyll fluorescence in the body as a natural probe, and determines the toxicity effect of pollutants by measuring the variation of photosynthetic fluorescence parameters. It has the advantages of fast and convenient measurement and real-time online detection. The widely used photosynthetic fluorescence parameters are the maximal quantum yield of photosystem II (Fv/Fm) and performance index PIABS. There are the problems that the sensitivity is not high enough, and the substances that can be detected are limited when researchers use Fv/Fm and PIABS as indicators to detect the comprehensive toxicity in water. So, in this paper, we proposed a construction method of Performance Index of Comprehensive Toxicity Effect (PICTE) using multi-parameter fusion based on the chlorophyll a fluorescence rise kinetics curve (OJIP) of algae. The fluorescence information of point J and point I in the curve was integrated. The area surrounded by the curve and the time corresponding to point J and point I were weighted for data items to construct PICTE. On this basis, Chlorella vulgaris was used as the tested algae species to compare the performance differences of Fv/Fm, PICTE, PIABS in the detection of toxic substances under the stress of five common water pollutants: Diuron (DCMU, 3-(3,4-dichlorophenol)-1,1-dimethylurea), Dibromothymoquinone (DBMIB, 2,5-dibromo-3-methyl-6-isopropyl-benzoquinone), Methyl viologen (MV, 1,1ꞌ-dimethyl-4,4ꞌ-bipyridinium-dichloride), Malathion, Carbofuran. The performance differences of Fv/Fm, PICTE, PIABS in detecting toxic substances, including lowest detection limit, highest response concentration, stability, and reproducibility, were studied. The results show that: in terms of toxicity detection, the constructed PICTE was sensitive to all five toxic substances and could detect more kinds of pollutants than Fv/Fm. The lowest detection limit of PICTE for five toxic substances compared with PIABS was reduced by 74.43%, 77.01%, 67.30%, 60.69%, and 50.81%, respectively. At the same time, it has a stronger ability to detect toxic substances with high concentration. The stability and reproducibility of PICTE for detecting the toxicity of DCMU, DBMIB, Malathion, and Carbofuran were all excellent, and all of the relative standard deviation (RSD) was < 5%. This research provides an important basis for constructing a highly sensitive and high-precision detection method for comprehensive toxicity in water.

Infrared spectroscopy and forensic entomology: Can this union work? A literature review.

For more than two decades, infrared spectroscopy techniques combined with multivariate analysis have been efficiently applied in several entomological fields, such as Taxonomy and Toxicology. However, little is known about its use and applicability in Forensic entomology (FE) field, with vibrational techniques such as Near-infrared spectroscopy (NIRS) and Medium-infrared spectroscopy (MIRS) underutilized in forensic sciences. Thus, this work describes the potential of NIRS, MIRS, and other spectroscopic methodologies, for entomological analysis in FE, as well as discusses its future uses for criminal or civil investigations. After a thorough research on scientific journals database, a total of 33 publications were found in scientific journals, with direct or indirect application to FE, including experimental applications of NIRS and MIRS in taxonomic discrimination of species, larval age prediction, detection of toxic substances in insects from environments or crime scenes, and detection of internal or external infestations by live or dead insects in stored products. Besides, NIRS and MIRS combined with multivariate analysis were efficient, inexpensive, fast, and non-destructive analytical tools. However, more than 51% of the spectroscopic publications are concentrated in the stored products field, and so we discuss the need for expansion and more direct application in other FE areas. We hope the number of articles continues to increase, and as NIRS and MIRS technology progress, they advance in forensic research and routine use.

Ranunculus constantinopolitanus Bitkisinin Bazı Bitkisel Özellikleri, Besleme Değeri ve Tohumlarına Ait Çimlenme Oranlarının Belirlenmesi

Çayır mera alanlarında yoğun olarak bulunan ve tüketildiğinde hayvanlar üzerinde toksik etki yapabilen Ranunculus constantinopolitanus (DC.) d‘Urv. bitkisine ait bazı bitkisel özellikler, besleme değeri ve tohumlarına ait çimlenme oranlarının belirlenmesi amacıyla bu çalışma yürütülmüştür. Bu çalışmanın bitkisel materyalini, 2018 yılında Bingöl il merkezine bağlı Çayağzı köyü mevkiinde bulunan çayır alanından tesadüfi örnekleme yöntemi ile toplanan 50 adet Ranunculus constantinopolitanus bitkisi oluşturmaktadır. Ranunculus constantinopolitanus bitkisine ait bitkisel özelliklerden bitki boyu 39-70 cm, bitki sap çapı 1,83-5,53 mm, bitkide çiçek sayısı 3-17 adet, bitkide yaprak sayısı 4-10 adet, yaprak uzunluğu 3-7 cm, yaprak genişliği 4-8 cm, bitki kuru ağırlığı 0,75-3,33 gram, bitkide sap oranı %35,1-86,5, bitkide yaprak oranı %3,9-42,7, bitkide çiçek oranı %4,0-43,4, bitkide meyve sayısı 4,0-11,0 adet, meyvede aken sayısı 18,0-36,0 adet, bitki başına aken sayısı 26-180 adet ve akenlerin bin tane ağırlığı 4,31-5,03 gram arasında değişim göstermiştir. Ranunculus constantinopolitanus bitkisine ait besleme değerlerinden kuru madde oranı %90,5-90,6, ham protein oranı %13,1-13,4, ADF oranı %34,9-35,9, NDF oranı %47,3-48,9, ADP oranı %0,33-0,37, Ca oranı %1,16-1,22, Mg oranı %0,37-0,38, P oranı %0,26-0,27 ve K oranı %0,94-0,97 arasında değişim göstermiştir. Bitki tohumları ile yapılan çimlenme testi sonucunda ise toplam 400 adet tohumdan 21. günün sonunda 87 adet tohumun çimlendiği ve toplam çimlenme oranının %21,8 olduğu belirlenmiştir. İleride yapılacak çalışmalar ile bu bitkinin içerdiği zehirli maddeler ve diğer besin elementlerinin tespit edilmesi, bu bitkinin daha iyi tanınmasını sağlayacaktır.

Potentiometric Biosensing Applications of Graphene Electrodes with Stabilized Polymer Lipid Membranes

This review provides information and details about the fabrication of biosensors composed of lipid membranes that can be used to rapidly detect toxic compounds in food, environmental pollutants, and analytes of clinical interest. Biosensors based on polymeric lipid membranes have been used to rapidly detect a wide range of these analytes, offering several advantages including fast response times, high sensitivity and selectivity, portability for field applications, and small size. A description of the construction of these devices and their applications for the rapid detection of toxic substances in food, environmental pollutants, and analytes of clinical interest is provided in this review.

Preparation and Characterization of Dual-Template Molecularly Imprinted Membrane with High Flux Based on Blending the Inorganic Nanoparticles

In this study, the dual-template molecularly imprinted composite membrane (D-MIM) was synthesized using ferulic acid and cinnamic acid as the mixed templates, α-methacrylic acid as functional monomer, ethylene glycol dimethacrylate as crosslinker, 2,2-azobisisobutyronitrile as photoinitiator inducing polymerization reaction, furthermore blended nanoparticles so as to improve mechanical strength and pure water flux of membrane. This paper has researched that the effect of variety of nanoparticles and its quantity, the quantity of photoinitiator, total template–functional monomer (T/F) ratio on performance of prepared membrane. The study has founded optimum parameters of synthesis: nanoparticles 18 nm TiO2 of 1 wt%, photoinitiator of 0.3 g, T/F ratio is 1:3. Under the above conditions, D-MIM would present a high separation efficiency of template molecules (ferulic acid and cinnamic acid) and the analogues (caffeic acid and syringic acid) with the permeation rate of about 100%. However, the permeation rate of glucose which has an analogous formula weight and extremely different structure is about 60%. From the foregoing, it showed that the D-MIM has specific selectively to the template molecules and its analogues, but the substances which have obvious distinctions in structure would present low permeation rate. It can be seen that D-MIM can identify the same kind of substance with specificity. Therefore, it can be used in the enrichment and separation of some active ingredients of traditional Chinese medicine, the detection of toxic substances in food and so on. Finally, the scanning electron microscope and FT-IR spectrometer has been used to visualize the structure morphology of the prepared membrane and to quantity the surface characteristics.

Development of a Compact, Highly-sensitive and Low-cost Biological Monitoring Method using Protozoa for Detecting Toxicants in Aquatic Environment

A novel method for biological monitoring to detect toxic substances in water was developed by using the protozoan Raphidiophrys contractilis as an indicator organism. In this system (named HELIOSENSOR), the adhesion of R. contractilis to the substratum was used as a measure of the health of the living organisms. A flow-through type chamber was designed for toxicity testing, in which cells that had been damaged by harmful materials were flushed away by the water flow. The number of protozoa was continuously monitored with a digital camera. The test results revealed that this monitoring system has high durability and efficiency compared with other bio-monitoring systems, enabling us to make a quicker and easier detection of toxic substances. This system showed particularly high sensitivity to heavy metals such as mercury, arsenic, lead and cadmium. Due to high sensitivity (ex. ~ 10-7 M for Hg2+), fast response time (less then 20 min) and small size (30×14×20 cm), this system has distinct advantages over other conventional biomonitoring systems using multicellular animals such as fish and crustaceans.

Detection of toxic substances in microbial fuel cells

Microbial fuel cells (MFCs) is a highly promising bioelectrochemical technology and uses microorganisms as catalyst to convert chemical energy directly to electrical energy. Microorganisms in the anodic chamber of MFC oxidize the substrate and generate electrons. The electrons are absorbed by the anode and transported through an external circuit to the cathode for corresponding reduction. The flow of electrons is measured as current. This current is a linear measure of the activity of microorganisms. If a toxic event occurs, microbial activity will change, most likely decrease. Hence, fewer electrons are transported and current decreases as well. In this way, a microbial fuel cell-based biosensor provides a direct measure to detect toxicity for samples. This paper introduces the detection of antibiotics, heavy metals, organic pollutants and acid in MFCs. The existing problems and future application of MFCs are also analyzed.

Colorimetric test-systems based on molecular imprinted polymer for detection of toxic substances

Colorimetric test-systems based on molecular imprinted polymer for detection of toxic substances

Toxic detection in mine water based on proteomic analysis of lysosomal enzymes in Saccharomyces cerevisiae.

ObjectivesLysosome is the cell-organelle which is commonly used as biomonitoring tool in environmental pollution. In this study, the lysosomal proteomic of the yeast Saccharomyces cerevisiae was analyzed for utilization in the detection of toxic substances in mine water samples.MethodsThis work informs the expression of lysosomal proteomic in yeast in response with toxic chemicals, such as sodium meta-arsenite and tetracycline, for screening specific biomarkers. After that, a recombinant yeast contained this biomarker were constructed for toxic detection in pure toxic chemicals and mine water samples.ResultsEach chemical had an optimal dose at which the fluorescent protein intensity reached the peak. In the case of water samples, the yeast showed the response with sample 1, 3, 4, and 5; whereas there is no response with sample 2, 6, and 7.ConclusionsThe recombinant yeast showed a high ability of toxic detection in response with several chemicals such as heavy metals and pharmaceuticals. In the case of mine water samples, the response varied depending on the sample content.

Síndrome de abstinencia neonatal: evolución en los últimos diez años

Introduction: Neonatal abstinence syndromes defined as a group of symptoms experienced by the newborn after the withdrawal of addictive drugs. Currently substance abuses one of the most important health problems in our society. Drug abuse by pregnant women is a relatively common condition and involves serious consequences for newborns.Aim: To know the state of the prevalence and incidence of neonatal abstinence syndrome (NAS), as reflected in the literature.Methodology: It has been held a bibliographical search through the databases offered by the library of the University of Seville: IMEbiomedicine, PubMed, SCOPUS, CINAHL, CUIDEN and The Cochrane Library Plus.Results: 627 articles have been found in total of which 62 articles seemed to be valid finally selecting 22 which have added 5 more articles, from a secondary search admitting a total of 27articles.Conclusions: After the review it has been observed an increase in prevalence in recent years regarding drug use in women of child bearing age and pregnant women which has resulted in an increase of neonatal abstinence syndrome. So it would be recommendable conducting population studies to check with greater verisimilitude the incidence of SAN along with the prevention and detection of toxic substances in pregnancy which could be useful to reduce the numbers of cases.

Maggots reveal a case of antemortal insect infestation

Insects on corpses can give a wide range of information in forensic investigations. The most common application is calculating when insects oviposited on a dead person to give an estimation of the postmortem interval [1]. Since the infestation of a dead body may be delayed by certain circumstances such as indoor locations [2] or wrapping [3], it is more accurate to talk about the colonization time. Insects, being restricted to a certain area, can give further hints to the investigators such as if a body has been moved to a different location after death; also, body parts of insects can link a suspect to a crime scene [4]. Another application is the detection of toxic substances in insects feeding from dead persons' tissues [5]. There have been several studies done according to the biology of these animals' living associated with corpses as well as their application in legal investigations in the last years [6–12]. Many necrophagous flies are attracted by the odor of decomposition [13], but for some, other odors such as those from urine, feces, and the associated bacterial fauna are quite attractive and stimulate oviposition [14, 15]. The infestation of the living by dipterous fly larvae is known as myiasis. Wounds or anogenital regions are often found being fed by maggots in cases of neglect in humans or animals [16–19]. In certain cases, the chronologically nonmatching infestation of the anogenital area and favorable sites for oviposition of flies being attracted by the dead, such as the face, can give both the information of how long somebody has been neglected as well as how long a person has been dead [14, 15, 20]. Flies of the genus Lucilia belong to one of the first and most abundant summer species on corpses in Europe [21] and play an important role as facultative parasite causing myiasis [22]. It has to be emphasized that blowfly maggots will mostly feed from necrotic tissues [23] and will seldom eat the fresh and healthy skin or organs in humans or animals which has been reported for other fly species such as those from the family Oestridae under mostly tropical circumstances [24]. This unique property of fly maggots is commonly used in the maggot debridement therapy for treating nonhealing wounds [25]. Sterile fly larvae are applied to such resulting in a cleaning, disinfection, and increased healing-rate of the damaged tissue. The green bottle fly Lucilia sericata is the usual species used in this form of wound management [26]. The following case of an elderly dead woman reports the possibility to distinguish between maggot infestation before and after death, helping to reconstruct the formerly unknown circumstances.

Effects of Toxic Organotin Compounds on Bacteria Investigated by Micro‐Raman Spectroscopy

Within the framework of the detection of toxic substances using specific bacteria, the effect of the toxic chemical compound tributyltin chloride (TBT) on the bacterium Escherichia coli TBT3 was investigated using a noninvasive approach based on micro‐Raman spectroscopy. Various cellular densities with optical density (OD) ranging from 1 to 4 and harvested at different growth phases were induced for 1 h with different TBT concentrations: 1, 3, 5, and 10 µM. As an original contribution, the Raman results show that, in these conditions, the vibrational signatures of bacteria were affected by the presence of the toxic TBT compound, mainly in the signal characteristics from carbohydrates and lipids. Hierarchical cluster analysis (HCA) carried out on the Raman data in these regions makes it possible to classify the spectra in three groups according to the TBT concentration, confirming the progressive influence of the chemical pollutant on the bacterium. This work shows the potentiality for the Raman technique on this subject, even though a low detection threshold corresponding with a concentration of 1 µM of TBT was established.

Dithiocarbamate fungicide thiram detection: Comparison of bioluminescent and fluorescent whole-cell bioassays based on hsp22 stress promoter induction

Detection of toxic substances interfering with endocrine system is one of the major preoccupations of the European community. A whole-cell bioassay for pollution detection based on stress induction has been designed. Well characterized toxicants, cadmium chloride and thiram (a dithiocarbamate fungicide), were used to optimize the detection conditions such as time-course conditions, cell line and reporter gene to be used. HeLa cells containing the firefly luciferase (luc) reporter gene under the control of the Drosophila melanogaster hsp22 promoter were compared to liver cells (HepG2) containing the same stress gene promoter fused either to the luc or the EGFP (Enhanced-Green Fluorescent Protein) gene. The sensitivity of the obtained bioassay was found to be enhanced by the concomitant use of liver cells and EGFP reporter gene. The detection limits of the toxicants were then lowered from 1 to 0.1 microM and from 1 to 0.01 microM for CdCl(2) and thiram, respectively.

Use of a microbial sensor: a new approach to the measurement of inhibitory effects on the microbial activity of activated sludge.

This paper presents a new method for the measurement of inhibitory effects in wastewater treatment plants on the basis of a continuous measurement of the microbial respiration product (CO(2)). The microbial sensor developed for this purpose consists of a small conical fluidized bed reactor connected to a cylindrical chamber that comprises part of the sample recirculation system. Activated sludge microbes are immobilized on spherical (diameter=1-2 mm) reticulated sinter glass carriers. Pure oxygen is supplied via the cylindrical chamber in order to sustain a highly dense population of microbial mass. The mean hydraulic retention time in the microbial sensor ranges between 30 and 40 min, while temperature is maintained at 30 degrees C, and pH 6.4. Carbon dioxide in the off-gas, which reflects the microbial activity, is continuously analyzed by means of an infrared analyzer. Inhibition of microbial activity (toxicity) can be determined as the mean percent reduction in carbon dioxide concentration. Several substances were tested and proved toxic to the microbes. With this microbial sensor, early detection of toxic substances becomes feasible, preventing them from entering an activated sludge unit operation.

The detection of toxic substances in entomological specimens.

Entomotoxicology (the study of drugs in insects), a new field of forensic investigations, has still to be precisely defined especially with respect to the toxic substances that can be assessed in entomological specimens. The aim of the present work was to review the relevant entomological publications in order to analyse and describe the various toxic substances that have been detected in biological specimens. Experimental studies have been reviewed separately from case reports. Toxic substances have been classified according to forensic toxicology methodology and on the basis of the chemical and analytical features. This classification will help investigators to identify the compounds that can be found in such biological samples and may stimulate new analytical research investigations. Given the heterogeneity of specimens, the use of non-specific tests (such as immunoenzyme assays) is not recommended and specific and sensitive techniques are suggested. Methods such as GC-MS and HPLC-MS allow the exact identification of the toxic substances and their metabolites.

Development of a bio-monitoring system for toxicants in water with fish

A bio-monitoring system for toxicants in water has been developed and verified for actual applications. This system is based on the motionality of five Acheilognathus lanceolata, a fish known to be very sensitive to toxic substances, moving around in an aquarium. Their movements are continuously monitored with a charge coupled device (CCD) camera and analyzed to find and quantify any abnormal behavior in their motional characteristics in comparison with the pre-acquired data. That is, the images of fish captured by a CCD camera are digitalized to identify the location of fish in a constant time interval and the locations of each fish were then analyzed mathematically with a personal computer using the equations proposed to determine the motional characteristics such as floatness, fledness and mobility(agility). These data are then converted by means of fuzzy estimation to an index value, defined as the contamination index (CI), by which the system provides the information about the overall toxic strength of the toxicant in the water flowing into the aquarium. If the fish are exposed to toxicant(s), the CI value will be proportional to the strength of its toxicity. The pilot test was performed in a water treatment plant for six months in order to verify the reproducibility of the system over the unstable conditions such as highly turbid water after rainfall as well as in normal conditions. The test results revealed that this monitoring system has good reproducibility and sensitivity, proving our approach, described in this paper, is reliable. As a result, this approach seems to enable us to make a quick and easy detection of toxic substances contained in water, therefore, this system can be applied to a source of water supply as a toxicant watching system.

Electrochemical enzyme immunoassay for detection of toxic substances

Electrochemical enzyme immunoassay for detection of toxic substances