Detection and quantification of low concentrations of 11-nor-delta-9-tetrahydrocannabinol-9-carboxylic acid from minimal amounts of urine

1991 ◽  
Vol 104 (5) ◽  
pp. 263-266 ◽  
Author(s):  
F. Mu�hoff ◽  
T. Daldrup
Keyword(s):  
Carboxylic Acid ◽  
Low Concentrations ◽  
Detection And Quantification

scholarly journals Investigations of infra-red spectra (2.5—7.5 µ ). Absorption of water

1940 ◽  
Vol 174 (957) ◽  
pp. 234-262 ◽  
Keyword(s):  
Carbon Tetrachloride ◽  
Carboxylic Acid ◽  
Intense Band ◽  
Low Concentrations ◽  
Sharp Band ◽  
Infra Red

During recent years much information has been obtained concerning the infra-red absorption of hydroxy bodies in the region about 3 µ number of investigators (Errera and Mollet 1936; Errera 1937 a ; Buswell, Deitz and Rodebush 1937; Buswell, Rodebush and Roy 1938; Davies and Sutherland 1938 a, b ; Fox and Martin 1937) have shown that at low concentrations in carbon tetrachloride a hydroxy body, whether an alcohol, phenol or carboxylic acid, has a sharp OH band at 2.75-2.83 µ , and as the concentration increases this band diminishes rapidly and is replaced by a wide intense band at longer wave-lengths, 3 µ and higher. The sharp band is due to the valency O-H vibration in the monomer, while at higher concentrations the molecules interfere with one another and modify the nature of the O-H vibrations in a manner which depends somewhat on the nature of the compound concerned.

scholarly journals Optimized HPLC -UV Method for Separation, Detection and Quantification of Endocrine Disrupting Estrogens in Low Quality Water

2017 ◽  
Vol 9 (3) ◽  
pp. 19
Author(s):  
Sijaona Cassian Msigala ◽  
Faith P Mabiki ◽  
Bjarne Styrishave ◽  
Robinson H Mdegela
Keyword(s):  
Emerging Contaminants ◽  
Limit Of Detection ◽  
Health Effect ◽  
Low Concentrations ◽  
Routine Monitoring ◽  
Relative Standard ◽  
Endocrine Disrupting ◽  
Quality Water ◽  
Living Organisms ◽  
Detection And Quantification

Endocrine disrupting estrogens are emerging contaminants in aquatic ecosystems and environment in general. There are no guidelines for routine monitoring of these chemicals, despite the existing evidences of their adverse health effect to living organisms at low concentrations. This study aimed at developing and validating an optimized HPLC-UV method for detection and quantification of estradiol and ethinylestradiol. Isocratic elution was used for separation and detection of ethinylestradiol and estradiol. The mobile phase was applied with A; water B; acetonitrile (50:50) at flow rate of 0.7mL/min and injection volume 10mL. The precision and accuracy of the method were within the acceptable range. Relative standard deviation of peak area for E2 ranged from 1.373 to 3.668%, and for EE2 ranged from 0.829 to 6.495 %. The percentage recovery for E2 ranged from 82.3 to 99.84 %, and for EE2 ranged from 84.6 to 103.52 %. Linearity of the method was realized at range of 2.5 to 50 ng/mL and 100 to 1000 ng/mL for both E2 and EE2. The linear regression coefficients were 0.9979 and 0.9973 for E2 whereas for EE2 were 0.9983 and 0.9976. Limit of detection were found to be 0.05 ng/mL and 0.08 ng/mL for E2 and EE2 respectively. The obtained limits of quantification were 0.18 and 0.28 ng/mL for E2 and EE2 respectively. In untreated sewage the concentrations of E2 and EE2 were 0.28 ng/ml and 0.18 ng/ml respectively. But in subsequent wastewater stabilization ponds the concentrations were below detection limit. Therefore, the optimized HPLC-UV method is suitable for detection and quantification of endocrine disrupting estrogens when a level of pollution is at least 0.15 ng/ml. At low extent of pollution would require use of the method in conjunction with ELISA technique.

Techniques for the detection and quantification of emerging contaminants

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Shanmugasundaram Shyamalagowri ◽  
Natarajan Shanthi ◽  
Jagadeesan Manjunathan ◽  
Murugesan Kamaraj ◽  
Arumugam Manikandan ◽  
...  
Keyword(s):  
Emerging Contaminants ◽  
Analytical Techniques ◽  
Wastewater Sludge ◽  
Environmental Matrices ◽  
Sample Collection ◽  
Soil Sediment ◽  
Low Concentrations ◽  
Air Sample ◽  
Detection And Quantification

Abstract In recent years, the diverse industrial practices and human inputs widely disseminated emerging contaminants (ECs) throughout environmental matrices, which is of great concern. Even at low concentrations, ECs pose major ecological problems and threaten human health and the environment’s biota. Consequently, people’s interest and concerns on the widespread dissemination of environmentally connected ECs of great concern as developed due to their scientific understanding, technical innovation, and socioeconomic awareness. Increased detection of contaminants may occur from climatic, socioeconomic, and demographic changes and the growing sensitivity of analytical techniques. Hence, this article reviews the determination of ECs in ecological specimens, from aquatic setup (river water, marine water, and wastewater), sludge, soil, sediment, and air. Sample collection and the quality measures are summarized. The preparation of samples, including extraction and cleanup and the subsequent instrumental analysis of ECs, are all covered. Traditional and recent extraction and cleanup applications to analyze ECs in samples are reviewed here in this paper. The detection and quantification of ECs using gas chromatography (GC) and liquid chromatography (LC) linked with various detectors, particularly mass spectrometry (MS), is also summarized and explored, as are other possible techniques. This study aims to give readers a more excellent knowledge of how new and improved approaches are being developed and serve as a resource for researchers looking for the best method for detecting ECs in their studies.

scholarly journals Critical Assessment of Mycotoxins in Beverages and Their Control Measures

Toxins ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 323
Author(s):  
Md. Shofiul Azam ◽  
Shafi Ahmed ◽  
Md. Nahidul Islam ◽  
Pulak Maitra ◽  
Md. Mahmudul Islam ◽  
...  
Keyword(s):  
Secondary Metabolites ◽  
Human Health ◽  
Ochratoxin A ◽  
Food Chain ◽  
Critical Assessment ◽  
Control Measures ◽  
Alternariol Methyl Ether ◽  
Low Concentrations ◽  
High Concern ◽  
Detection And Quantification

Mycotoxins are secondary metabolites of filamentous fungi that contaminate food products such as fruits, vegetables, cereals, beverages, and other agricultural commodities. Their occurrence in the food chain, especially in beverages, can pose a serious risk to human health, due to their toxicity, even at low concentrations. Mycotoxins, such as aflatoxins (AFs), ochratoxin A (OTA), patulin (PAT), fumonisins (FBs), trichothecenes (TCs), zearalenone (ZEN), and the alternaria toxins including alternariol, altenuene, and alternariol methyl ether have largely been identified in fruits and their derived products, such as beverages and drinks. The presence of mycotoxins in beverages is of high concern in some cases due to their levels being higher than the limits set by regulations. This review aims to summarize the toxicity of the major mycotoxins that occur in beverages, the methods available for their detection and quantification, and the strategies for their control. In addition, some novel techniques for controlling mycotoxins in the postharvest stage are highlighted.

scholarly journals Quantification of Cadophora luteo-olivacea From Grapevine Nursery Stock and Vineyard Soil Using Droplet Digital PCR

Plant Disease ◽  
2020 ◽  
Vol 104 (8) ◽  
pp. 2269-2274 ◽  
Author(s):  
María Mercedes Maldonado-González ◽  
María del Pilar Martínez-Diz ◽  
Marcos Andrés-Sodupe ◽  
Rebeca Bujanda ◽  
Emilia Díaz-Losada ◽  
...  
Keyword(s):  
Environmental Samples ◽  
Digital Pcr ◽  
Fungal Species ◽  
Droplet Digital Pcr ◽  
Taqman Probe ◽  
Planting Material ◽  
Low Concentrations ◽  
Nursery Stock ◽  
Species Specific ◽  
Detection And Quantification

Cadophora luteo-olivacea is the most prevalent Cadophora species associated with Petri disease and esca of grapevine. Accurate, early, and specific detection and quantification of C. luteo-olivacea are essential to alert growers and nurseries to the presence of the pathogens in soil and to prevent the spread of this pathogen through grapevine planting material. The aim of this study was to develop molecular tools to detect and quantify C. luteo-olivacea inoculum from environmental samples. Species specific primers based on the β-tubulin gene and a TaqMan probe for droplet digital PCR (ddPCR) and quantitative PCR (qPCR) were first developed to detect and quantify purified DNA of the target fungus. Specificity tests showed that the primers were able to amplify the C. luteo-olivacea DNA (20 isolates) while none of the 29 nontarget fungal species (58 isolates) tested were amplified. The ddPCR was shown to be more sensitive compared with qPCR in the detection and quantification of C. luteo-olivacea at very low concentrations and was further selected to accurately detect and quantify the fungus from environmental samples. Twenty-five of the 94 grafting plants (26.6%) analyzed by ddPCR tested positive to C. luteo-olivacea DNA (>3 copies/µl). C. luteo-olivacea was barely detected from vineyard soils. The procedure employed in this study revealed the presence of the pathogen in symptomless vines, which makes implementation of this technique suitable for certification schemes of C. luteo-olivacea-free grapevine planting material.

scholarly journals Thermographic detection and quantification of THC in oral fluid at unprecedented low concentrations

2020 ◽  
Vol 11 (4) ◽  
pp. 2178 ◽  
Author(s):  
Damber Thapa ◽  
Nakisa Samadi ◽  
Nisarg Patel ◽  
Nima Tabatabaei
Keyword(s):  
Oral Fluid ◽  
Low Concentrations ◽  
Detection And Quantification

scholarly journals Room temperature amine sensors enabled by sidewall functionalization of single-walled carbon nanotubes

RSC Advances ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 5578-5585 ◽  
Author(s):  
Clara Paoletti ◽  
Maggie He ◽  
Pietro Salvo ◽  
Bernardo Melai ◽  
Nicola Calisi ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Carboxylic Acid ◽  
Room Temperature ◽  
Single Walled Carbon Nanotubes ◽  
Single Walled Carbon ◽  
Low Concentrations ◽  
Chemiresistive Sensor ◽  
Walled Carbon Nanotubes

Chemiresistive sensor based on sidewall modified SWCNTs with perfluorophenyl molecules bearing carboxylic acid were prepared for the detection of low concentrations (5–40 ppm) of gaseous NH3 and TMA at room temperature.

scholarly journals A Colorimetric Dip Strip Assay for Detection of Low Concentrations of Phosphate in Seawater

Sensors ◽  
2021 ◽  
Vol 21 (9) ◽  
pp. 3125
Author(s):  
Hojat Heidari-Bafroui ◽  
Amer Charbaji ◽  
Constantine Anagnostopoulos ◽  
Mohammad Faghri
Keyword(s):  
Limit Of Detection ◽  
Storage Conditions ◽  
Ammonium Molybdate ◽  
Sargasso Sea ◽  
Detection Zone ◽  
Liquid Form ◽  
Limits Of Detection ◽  
Low Concentrations ◽  
Phosphate Detection ◽  
Detection And Quantification

Nutrient pollution remains one of the greatest threats to water quality and imposes numerous public health and ecological concerns. Phosphate, the most common form of phosphorus, is one of the key nutrients necessary for plant growth. However, phosphate concentration in water should be carefully monitored for environmental protection requirements. Hence, an easy-to-use, field-deployable, and reliable device is needed to measure phosphate concentrations in the field. In this study, an inexpensive dip strip is developed for the detection of low concentrations of phosphate in water and seawater. In this device, ascorbic acid/antimony reagent was dried on blotting paper, which served as the detection zone, and was followed by a wet chemistry protocol using the molybdenum method. Ammonium molybdate and sulfuric acid were separately stored in liquid form to significantly improve the lifetime of the device and enhance the reproducibility of its performance. The device was tested with deionized water and Sargasso Sea seawater. The limits of detection and quantification for the optimized device using a desktop scanner were 0.134 ppm and 0.472 ppm for phosphate in water and 0.438 ppm and 1.961 ppm in seawater, respectively. The use of the portable infrared lightbox previously developed at our lab improved the limits of detection and quantification by a factor of three and were 0.156 ppm and 0.769 ppm for the Sargasso Sea seawater. The device’s shelf life, storage conditions, and limit of detection are superior to what was previously reported for the paper-based phosphate detection devices.

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.

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