scholarly journals The Double Face of Ketamine—The Possibility of Its Identification in Blood and Beverages

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 813
Author(s):  
Magdalena Świądro ◽  
Paweł Stelmaszczyk ◽  
Irena Lenart ◽  
Renata Wietecha-Posłuszny
Keyword(s):  
Date Rape ◽  
Signal To Noise Ratio ◽  
High Sensitivity ◽  
Heroin Addiction ◽  
Assisted Extraction ◽  
Low Concentrations ◽  
High Concentrations ◽  
Rosé Wine ◽  
Tof Ms

The purpose of this study was to develop and validate a high-sensitivity methodology for identifying one of the most used drugs—ketamine. Ketamine is used medicinally to treat depression, alcoholism, and heroin addiction. Moreover, ketamine is the main ingredient used in so-called “date-rape” pills (DRP). This study presents a novel methodology for the simultaneous determination of ketamine based on the Dried Blood Spot (DBS) method, in combination with capillary electrophoresis coupled with a mass spectrometer (CE-TOF-MS). Then, 6-mm circles were punched out from DBS collected on Whatman DMPK-C paper and extracted using microwave-assisted extraction (MAE). The assay was linear in the range of 25–300 ng/mL. Values of limits of detection (LOD = 6.0 ng/mL) and quantification (LOQ = 19.8 ng/mL) were determined based on the signal to noise ratio. Intra-day precision at each determined concentration level was in the range of 6.1–11.1%, and inter-day between 7.9–13.1%. The obtained precision was under 15.0% (for medium and high concentrations) and lower than 20.0% (for low concentrations), which are in accordance with acceptance criteria. Therefore, the DBS/MAE/CE-TOF-MS method was successfully checked for analysis of ketamine in matrices other than blood, i.e., rose wine and orange juice. Moreover, it is possible to identify ketamine in the presence of flunitrazepam, which is the other most popular ingredient used in DRP. Based on this information, the selectivity of the proposed methodology for identifying ketamine in the presence of other components of rape pills was checked.

scholarly journals Electroanalytical Techniques for the Detection of Selenium as a Biologically and Environmentally Significant Analyte—A Short Review

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1768
Author(s):  
Miroslav Rievaj ◽  
Eva Culková ◽  
Damiána Šandorová ◽  
Zuzana Lukáčová-Chomisteková ◽  
Renata Bellová ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Essential Element ◽  
Analytical Techniques ◽  
High Sensitivity ◽  
Stripping Voltammetry ◽  
Short Review ◽  
Electroanalytical Methods ◽  
High Concentrations ◽  
Speed Of Analysis

This short review deals with the properties and significance of the determination of selenium, which is in trace amounts an essential element for animals and humans, but toxic at high concentrations. It may cause oxidative stress in cells, which leads to the chronic disease called selenosis. Several analytical techniques have been developed for its detection, but electroanalytical methods are advantageous due to simple sample preparation, speed of analysis and high sensitivity of measurements, especially in the case of stripping voltammetry very low detection limits even in picomoles per liter can be reached. A variety of working electrodes based on mercury, carbon, silver, platinum and gold materials were applied to the analysis of selenium in various samples. Only selenium in oxidation state + IV is electroactive therefore the most of voltammetric determinations are devoted to it. However, it is possible to detect also other forms of selenium by indirect electrochemistry approach.

Manometric and Electrode-Probe Determination of CO2 in Fish Flesh

1982 ◽  
Vol 45 (10) ◽  
pp. 932-934 ◽  
Author(s):  
JIM W. CONRAD ◽  
GLENN C. ROBERTS ◽  
HAROLD J. BARNETT
Keyword(s):  
Mean Difference ◽  
Fish Products ◽  
Probe Technique ◽  
Fish Flesh ◽  
Ion Probe ◽  
Low Concentrations ◽  
Manometric Method ◽  
High Concentrations ◽  
Manometric Technique

A rapid electrometric method for determining endogenous and added CO2 in fish products was studied using an Orion CO2 probe and Orion ionalyzer model #801. Analytical results were compared to those using the standard Warburg manometric technique. Comparisons showed a ± 20.8% mean difference for low concentrations of CO2 (<350 ppm) and a ± 10.7% mean difference for high concentrations of CO2 (>800 ppm). The probe technique was found to be easier to use and required less time for operating and cleanup procedures than the manometric method. Based on recovery studies, the specific ion probe was more accurate at all levels of CO2 evaluated than the manometric device.

scholarly journals Determination of Fungi and Multi-Class Mycotoxins in Camelia sinensis and Herbal Teas and Dietary Exposure Assessment

Toxins ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 555
Author(s):  
Ingars Reinholds ◽  
Estefanija Bogdanova ◽  
Iveta Pugajeva ◽  
Laura Alksne ◽  
Darta Stalberga ◽  
...  
Keyword(s):  
Exposure Assessment ◽  
Daily Intake ◽  
Dietary Exposure ◽  
Fungal Species ◽  
Two Dimensional ◽  
Flight Mass Spectrometry ◽  
Low Concentrations ◽  
Exposure Levels ◽  
Tof Ms

In this paper, a study of fungal and multi-mycotoxin contamination in 140 Camellia sinensis and 26 herbal teas marketed in Latvia is discussed. The analysis was performed using two-dimensional liquid chromatography with time-of-flight mass spectrometry (2D-LC-TOF-MS) and MALDI-TOF-MS. In total, 87% of the tea samples tested positive for 32 fungal species belonging to 17 genera, with the total enumeration of moulds ranging between 1.00 × 101 and 9.00 × 104 CFU g−1. Moreover, 42% of the teas (n = 70) were contaminated by 1 to 16 mycotoxins, and 37% of these samples were positive for aflatoxins at concentrations ranging between 0.22 and 41.7 µg kg−1. Deoxynivalenol (DON) and its derivatives co-occurred in 63% of the tea samples, with their summary concentrations reaching 81.1 to 17,360 µg kg−1. Ochratoxin A (OTA), enniatins, and two Alternaria toxins were found in 10–37% of the teas at low concentrations. The dietary exposure assessment based on the assumption of a probable full transfer of determined mycotoxins into infusions indicated that the analysed teas are safe for consumers: the probable maximum daily exposure levels to OTA and the combined DON mycotoxins were only 0.88 to 2.05% and 2.50 to 78.9% of the tolerable daily intake levels.

Inorganic polysulfides’ quantitation by methyl iodide derivatization: dimethylpolysulfide formation potential

2004 ◽  
Vol 49 (9) ◽  
pp. 179-184 ◽  
Author(s):  
A. Goifman ◽  
D. Ryzkov ◽  
J. Gun ◽  
A. Kamyshny ◽  
A.D. Modestov ◽  
...  
Keyword(s):  
Methyl Iodide ◽  
Direct Determination ◽  
Solubility Limit ◽  
Environmental Significance ◽  
Valuable Alternative ◽  
Natural Systems ◽  
Low Concentrations ◽  
Inorganic Polysulfides ◽  
High Concentrations

Inorganic polysulfides are important intermediates in the formation of dimethylpolysulfides and possibly other volatile sulfur compounds of environmental significance. Currently, direct determination of these ions in the concentration range of natural systems is practically impossible, particularly under oxic conditions. Polysulfide quantification by derivatization with methyl iodide or d6-methyl iodide is emerging as a valuable alternative method for studies of polysulfide formation in natural systems. This manuscript presents detailed studies aimed at the evaluation of this method. We determined the conversion of the inorganic polysulfides to dimethylpolysulfides by methylation with methyl iodide. Close to 100 per cent of the molar concentration of polysulfide salts were converted to organic polysulfides for very low concentrations of dissolved polysulfide solutions, but only a small recovery was obtained for high concentrations of polysulfide precursors or when the solubility limit was exceeded. The recovery of polysulfides based on the calculated dissolved polysulfide concentration exceeds 1,000 per cent for very low dissolved concentrations of polysulfides. This unexpected dependence is attributed to continuous inorganic polysulfide formation from hydrogen sulfide and sulfur precipitate concurrent with, and in fact driven by, the methylation process.

scholarly journals Determination of Zinc-Based Additives in Lubricating Oils by Flow-Injection Analysis with Flame-AAS Detection Exploiting Injection with a Computer-Controlled Syringe

2005 ◽  
Vol 2005 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Gustavo Pignalosa ◽  
Moisés Knochen ◽  
Noel Cabrera
Keyword(s):  
Flow Injection ◽  
Computer Control ◽  
Injection System ◽  
Mean Values ◽  
Lubricating Oils ◽  
Low Concentrations ◽  
Flow Injection System ◽  
High Concentrations ◽  
Zinc Levels

A flow-injection system is proposed for the determination of metal-based additives in lubricating oils. The system, operating under computer control uses a motorised syringe for measuring and injecting the oil sample (200μL) in a kerosene stream, where it is dispersed by means of a packed mixing reactor and carried to an atomic absorption spectrometer which is used as detector. Zinc was used as model analyte. Two different systems were evaluated, one for low concentrations (range 0–10 ppm) and the second capable of providing higher dilution rates for high concentrations (range 0.02%–0.2% w/w). The sampling frequency was about 30 samples/h. Calibration curves fitted a second-degree regression model (r2= 0.996). Commercial samples with high and low zinc levels were analysed by the proposed method and the results were compared with those obtained with the standard ASTM method. Thettest for mean values showed no significant differences at the 95% confidence level. Precision (RSD%) was better than 5% (2% typical) for the high concentrations system. The carryover between successive injections was found to be negligible.

scholarly journals Determination of Histamine in Tomatoes by Capillary Electrophoresis

2000 ◽  
Vol 83 (1) ◽  
pp. 89-94 ◽  
Author(s):  
Elek Bolygo ◽  
Paul A Cooper ◽  
K Michael Jessop ◽  
Frank Moffatt
Keyword(s):  
Capillary Electrophoresis ◽  
Signal To Noise Ratio ◽  
High Sensitivity ◽  
Flow Cell ◽  
Voltage Gradient ◽  
Signal To Noise ◽  
Tomato Fruits ◽  
Endogenous Level ◽  
Selection Of

Abstract An improved capillary electrophoresis assay for histamine in crude extracts was developed and used to determine histamine levels in a selection of tomato fruits and pastes. Performance in terms of reproducibility and sensitivity was optimized by use of a high sensitivity detector flow cell, sodium hydroxide rinses, and a voltage gradient. The method was linear down to 0.2 μg/mL (signal-to-noise ratio = 4:1), which was below the endogenous level in all samples.

scholarly journals Association of polymorphism rs7903146 gene TCF7L2 with low concentrations of autoantibodies in latent autoimmune diabetes of adults (LADA)

2016 ◽  
Vol 19 (3) ◽  
pp. 199-203 ◽  
Author(s):  
Iuliia V. Silko ◽  
Tatiana V. Nikonova ◽  
Olga N. Ivanova ◽  
Svetlana M. Stepanova ◽  
Marina V. Shestakova ◽  
...  
Keyword(s):  
Odds Ratio ◽  
Autoimmune Diabetes ◽  
Polymorphic Marker ◽  
Healthy Individuals ◽  
Tcf7l2 Gene ◽  
Latent Autoimmune Diabetes ◽  
Low Concentrations ◽  
High Concentrations

Aim. To determine the frequencies of alleles and genotypes of polymorphic marker rs7903146 of the TCF7L2 gene in latent autoimmune diabetes in adults (LADA) and healthy individuals. The aims of the study were also to compare the distribution of alleles and genotypes and to explore the association with the development of LADA.Materials and methods. A total of 96 patients (46 females and 50 males) with LADA and 201 healthy individuals were examined. A quantitative determination of autoantibodies GADA, ICA, IA-2A and ZnT8 in the serum of LADA patients was performed. All patients underwent genotyping of rs7903146 of the TCF7L2 genes.Results. There was an increased frequency of the T allele and genotype T+ of marker rs7903146 of the TCF7L2 gene in patients with LADA with low concentrations of autoantibodies compared to a group of patients with high concentrations and with controls. We observed significant associations of the T allele and genotype T+ with LADA in patients with low concentrations of autoantibodies [p = 0.02; odds ratio (OR) = 1.85; 95% confidence interval (CI) = 1.10–3.13 and p = 0.04; OR = 2.14; 95% CI = 1.01–4.53 for the T allele and genotype T+, respectively).Conclusion. The results of the study suggest that LADA patients with low concentrations of autoantibodies have a genetically pre-determined similarity with patients with type 2 diabetes.

scholarly journals Atomic Absorption Spectrometric Determination of Chromium, Copper, Lead, Mercury, and Zinc in Sediments Collected in Bayou d'Inde, Southwestern Louisiana

2002 ◽  
Vol 85 (1) ◽  
pp. 225-232 ◽  
Author(s):  
Carey Hardaway ◽  
Kermit Gauthreaux ◽  
Joseph Sneddon ◽  
James N Beck
Keyword(s):  
Trace Metals ◽  
Atomic Absorption ◽  
Sediment Cores ◽  
Sedimentation Rates ◽  
Low Concentrations ◽  
High Concentrations ◽  
Atomic Absorption Spectrometric ◽  
Copper Lead

Abstract The concentrations of the metals chromium (Cr), copper (Cu), lead (Pb), mercury (Hg), and zinc (Zn) were determined in sediment cores taken from Bayou d'Inde in southwestern Louisiana. Previous studies had reported elevated concentrations of these trace metals in sediments along this waterway. The current study, conducted more than a decade later, was designed to determine if these metals had migrated from the areas of highest concentrations. Concentrations as high as 400 mg/kg for Cr, 1100 mg/kg for Cu, 10 mg/kg for Hg, and 600 mg/kg for Pb and Zn were found. Areas of high concentrations of metals were isolated within a distance of about 1 km from the most highly contaminated areas in the bayou. Low concentrations of metals were found at the mouth of the bayou. Estimated sedimentation rates of 0.67–1.2 cm/yr were based on the burial of the sediments originally studied. The concentrations of the metals studied remained high and were also highly localized, both spatially and temporally.

Effect of low fibrinogen concentrations on the rheology of human blood in vitro

1979 ◽  
Vol 236 (3) ◽  
pp. H447-H450
Author(s):  
W. Blattler ◽  
P. W. Straub ◽  
C. Jeanneret ◽  
G. S. Horak
Keyword(s):  
Human Blood ◽  
Cell Aggregation ◽  
Fibrinogen Concentration ◽  
Shear Rates ◽  
Red Blood Cell Aggregation ◽  
Low Concentrations ◽  
Normal Human ◽  
High Concentrations

The influence of low concentrations of fibrinogen on the rheology of normal human blood was investigated with an instrument that permitted simultaneous determination of viscosity and the state of red blood cell aggregation and deformation. Fibrinogen, in concentrations of 9-82 mg/100 ml, decreased blood viscosity at all shear rates below the value obtained with red blood cells suspended in serum. At concentrations above 116 mg/100 ml viscosity was increased. Aggregate formation increased progressively as the fibrinogen concentration increased, necessitating higher dispersing shear rates. The deformation and alignment of the red cells, occurring at a shear rate of 230 s-1, was facilitated by low concentrations. The effect of fibrinogen on low-shear viscosity is explained by the formation of different kinds of aggregates. At low concentrations, the aggregates consist of only few cells forming spherelike particles displaying hemodynamic properties better than those of the single discoid cells. At normal or high concentrations big rodlike aggregates occur and increase resistance to flow.

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