Application of Solid-Phase Micro-Extraction Technology to Drug Screening and Identification

2001 ◽  
Vol 38 (5) ◽  
pp. 541-547 ◽  
Author(s):  
Mohammad H Mosaddegh ◽  
Thomas Richardson ◽  
R W Stoddart ◽  
John McClure
Keyword(s):  
Solid Phase ◽  
Local Anaesthetics ◽  
Gas Chromatography Mass Spectrometry ◽  
Solid Phase Micro Extraction ◽  
Extraction Technology ◽  
Fibre Coating ◽  
Coefficients Of Variation ◽  
Screening And Identification ◽  
One Step ◽  
Temperature Time

Benzodiazepines, tricyclic antidepressants and local anaesthetics are frequently involved in poisoning episodes and fatalities. A specific, sensitive and rapid procedure for identifying and quantifying such drugs in postmortem matrices has been developed using solid-phase micro-extraction (SPME) and gas chromatography-mass spectrometry. Very clean extracts were obtained in one step using SPME. The most commonly used fibre coatings were tested to select the best coating for SPME of the drugs. The appropriate fibre coating for most drugs was polyacrylate, followed by Carbowax-divinylbenzene. A Hewlett-Packard 5890 gas chromatograph in combination with a Trio 2000 mass spectrometer was used to analyse the samples. Temperature, time, pH and addition of sodium chloride were optimized to obtain consistent extraction. The between-day and within-day coefficients of variation were less than 16% and less than 6%, respectively.

Hydrogen sulphide inhibits PSII of lichen photobionts

2013 ◽  
Vol 45 (1) ◽  
pp. 101-113 ◽  
Author(s):  
Stefano BERTUZZI ◽  
Mauro TRETIACH
Keyword(s):  
Hydrogen Sulphide ◽  
Vascular Plants ◽  
Solid Phase ◽  
Photosynthetic Apparatus ◽  
Sample Surface ◽  
Gas Chromatography Mass Spectrometry ◽  
Solid Phase Micro Extraction ◽  
Action Mechanisms ◽  
Species Specific ◽  
Closed Chambers

AbstractThe effects of hydrogen sulphide (H2S) on five lichens with different photobionts, ecology, and tolerance to the pollutant were studied by means of samples exposed in closed chambers containing two known H2S solutions. The H2S concentration in the void volume at equilibrium with the liquid phase was measured by gas chromatography-mass spectrometry, combined with the use of solid phase micro extraction (GC/MS SPME). It was determined as 8 and 28 ppm H2S in the absence of lichen material, andc. 2 and 10 ppm H2S respectively with living lichen material inserted for 8 hours in the exposure chambers. Significant differences in the species-specific emission of chlorophyllafluorescence (ChlaF) were observed, with a pronounced depression ofFv/Fmalready detectable after 2 h exposure at 28 ppm H2S in all the species. The decreased intensity was positively correlated to sample surface and, to a lesser extent, to the species-specific pre-exposureFv/Fmvalue. Dark-exposed samples were less affected than light-exposed ones. All four chlorolichens could recover the pre-exposure ChlaF emission after two days in the absence of H2S, both in the light and in the dark, whereas the cyanolichen did not recover when kept in the dark. The results are thoroughly discussed on the basis of the known action mechanisms of H2S on the photosynthetic apparatus of vascular plants and cyanobacteria.

Development of a Headspace-Solid Phase Micro Extraction Method for the Analysis of Volatile and Semi-Volatile Organic Compounds from Polyurethane Resins for Leather Finishing

2021 ◽  
Vol 116 (8) ◽  
Author(s):  
Antonia Flores ◽  
Silvia Sorolla ◽  
Concepció Casas ◽  
Rosa Cuadros ◽  
Anna Bacardit
Keyword(s):  
Gas Chromatography ◽  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Solid Phase ◽  
Monomethyl Ether ◽  
Gas Chromatography Mass Spectrometry ◽  
Extraction Temperature ◽  
Solid Phase Micro Extraction ◽  
Volatile Organic ◽  
Leather Finishing

Volatile organic compounds (VOCs) and Semi-Volatile Organic Compounds (SVOCs) arise from the chemicals used in the various stages of the leather manufacturing process. An important aim of the tanning industry is to minimize or eliminate VOCs and SVOCs, without lowering the quality of leather.   This paper shows the development of a new headspace-solid phase micro extraction coupled with gas chromatography–mass spectrometry (HS-SPME/GC-MS) method for the identification of VOCs and SVOCs emitted by newly designed polymers for the leather finishing operation. These new polymers are polyurethane resins designed to reduce the VOC and SVOC concentration. This method enables a simple and fast determination of the qualitative and semi-quantitative content of VOCs and SVOCs in polyurethane-type finishing resins. The chemicals that are of concern in this paper are the following: Dipropylene glycol Monomethyl Ether (DPGME), DBE-3 (a mixture of dibasic esters) and Triethylamine (TEA). The test conditions that have been determined to carry out the HS-SPME assay are the following: incubation time (2 hours), extraction temperature and time (40°C; 5 minutes) and the desorption conditions (280°C, 50 seconds).  Ten samples of laboratory scale resins were tested by HS-SPME followed by gas chromatography (GC-MS). DPGME and DBE-3 (a mixture of dimethyl adipate, dimethyl glutarate and dimethyl succinate) have been identified effectively. The compounds are identified by a quantitative method using external calibration curves for the target compounds. The technique is not effective to determine the TEA compound, since the chromatograms shown poor resolution peaks for the standard. 

scholarly journals Characteristic-Aroma-Component-Based Evaluation and Classification of Strawberry Varieties by Aroma Type

Molecules ◽  
2021 ◽  
Vol 26 (20) ◽  
pp. 6219
Author(s):  
Lixia Sheng ◽  
Yinan Ni ◽  
Jianwen Wang ◽  
Yue Chen ◽  
Hongsheng Gao
Keyword(s):  
Solid Phase ◽  
Economic Value ◽  
Gas Chromatography Mass Spectrometry ◽  
Volatile Components ◽  
Solid Phase Micro Extraction ◽  
Ripe Fruit ◽  
Volatile Organic ◽  
Different Types ◽  
Aroma Components

The unique fruity aroma of strawberries, a popular fruit of high economic value, is closely related to all the volatile organic compounds (VOCs) contained within them. Despite extensive studies on the identification of VOCs in strawberries, systematic studies on fruit-aroma-related VOCs are few, resulting in a lack of effective standards for accurately distinguishing aroma types. In the present study, solid-phase micro extraction and gas chromatography–mass spectrometry were used to analyze and identify VOCs in the ripe fruit of each of the 16 strawberry varieties at home and abroad and to explore their characteristic aroma components and the classification of such varieties by aroma type. The results suggested remarkable variations in the types and contents of VOCs in different strawberry varieties, of which esters were dominant. The principal volatile components, consisting of four esters, three alcohols, one aldehyde, and one ketone, in 16 strawberry varieties were detected based on the absolute and relative contents of VOCs in the fruit. The characteristic aroma components in strawberries, containing nine esters, six aldehydes, and one alcohol, were determined based on the aroma values of different VOCs, and the characteristic aroma components were divided into five types further based on aroma descriptions. Sixteen strawberry varieties were finally divided into four aroma types, namely, peachy, pineapple, fruity, and floral, based on the contributions of different types. The results provided a basis and standard for classifying strawberries by aroma type, studying the hereditary regularity of the fruity aroma of strawberries, and improving aroma quality.

scholarly journals Bioactivity and Volatile Profiling of Azadirachta indica Leaves for the Management of Maize Weevil, Sitophilus zeamais (Motsch.) Infestations

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
A.G.W.U. Perera ◽  
M.M.S.C. Karunaratne ◽  
S.D.M. Chinthaka
Keyword(s):  
Azadirachta Indica ◽  
Solid Phase ◽  
Biological Activities ◽  
Sitophilus Zeamais ◽  
Gas Chromatography Mass Spectrometry ◽  
Solid Phase Micro Extraction ◽  
Leaf Extracts ◽  
Maize Weevil ◽  
Biological Potential ◽  
Wide Range

Neem (Azadirachta indica A. juss), is known to possess a wide range of pharmacological properties and is thus commercially exploitable. Apart from its medicinal potential, a considerable progress has been achieved regarding biological potential and chemical composition of the leaves which is an ever-increasing interest to the scientific community. During this study, biological phenomena and secondary metabolite composition of A. indica leaves were examined in the management of Sitophilus zeamais on stored maize. Insecticidal and repellent potential of A. indica leaf powders were evaluated in both contact and fumigant forms. Phytochemical screening of 11 phyto constituents was performed following the standard procedures for n-hexane, dichloromethane, ethyl acetate, methanol and aqueous leaf extracts. Volatile profile of A. indica leaves was characterized by employing headspace-solid-phase micro extraction coupled with gas chromatography-mass spectrometry (HS-SPME/GC-MS). Over 60% weevil repellency was recorded at doses above 23.33%, whereas 100% and 67% contact and fumigation mortalities were observed respectively, 9 days after treatment at the dose of 33.33% and the respected LD50 values were 1.56 g and 4.48 g. Thirty two volatile compounds were identified in three distinct chemical classes (Monoterpenoid, sesquiterpenoid and purine nucleosides). γ-Elemene (24.06%), 3,7 (11)-eudesmadiene (6.83%), caryophyllene (6.40%), and 10s,11s-himachala-3(12),4-diene (6.36%) were the major constituents of neem leaf volatiles, followed by other compounds present in less than 4% which might be responsible for varied biological activities observed. Thus the odour impact of the bioassayguided study clearly implies that A. indica leaves can be harnessed against S. zeamais infestations.Keywords: Azadirachta indica, Sitophilus zeamais, headspace-solid-phase micro-extraction, insecticidal activity, repellency

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