scholarly journals Extraction of medicinal compounds of the benzodiazepines class from aqueous solutions and their following gas chromatographic determination

2021 ◽  
Vol 57 (2) ◽  
pp. 177-184
Author(s):  
O. N. Mikhniuk ◽  
S. M. Leshchev
Keyword(s):  
Aqueous Solutions ◽  
Chromatographic Determination ◽  
Selective Extraction ◽  
Gas Chromatography Mass Spectrometry ◽  
Chromatographic Technique ◽  
Psychotropic Substances ◽  
Quantitative Extraction ◽  
Relative Standard ◽  
Distribution Constants ◽  
The Republic

In extraction systems hexane–water, hexane–aqueous solutions of inorganic salts (sodium chloride, dipotassium phosphate and potassium carbonate), chloroform–water using the method of gas chromatography–mass spectrometry, the distribution constants of psychotropic substances, limited to movement through the customs border of the Republic of Belarus – alprazolam, lorazepam, temazepam, and as well as clozapine, a medicinal product permitted for movement, were determined. The greatest dynamics of the growth of the distribution constant versus salt concentration was observed in alprazolam. It was found that replacing hexane with chloroform leads to increasing the distribution constants and the quantitative extraction of all substances. However, for the selective extraction of substances from various objects and the simultaneous removal of matrix components, it is necessary to use the systems as hexane–aqueous solutions of salts or hexane–water. Based on the obtained values of the distribution constants of substances, extraction-chromatographic technique for the determination of organic non­electrolytes (benzodiazepines) in various objects is proposed. Metrological characteristics of the techniques are: relative standard deviation does not exceed 2 %, the range of determined concentrations in solutions is 0,05– 1,00 g/dm3.

scholarly journals Extraction-chromatographic determination of narcotic drugs and psychotropic substances in objects of complex matrix composition

2021 ◽  
Vol 65 (4) ◽  
pp. 422-430
Author(s):  
O. N. Mikhniuk ◽  
S. M. Leshchev
Keyword(s):  
Aqueous Solutions ◽  
Sharp Decrease ◽  
Chromatographic Determination ◽  
Matrix Composition ◽  
Gas Chromatography Mass Spectrometry ◽  
Maximum Efficiency ◽  
Psychotropic Substances ◽  
Matrix Components ◽  
Narcotic Drugs

A comparison of the capabilities of two methods for extraction-chromatographic determination of narcotic drugs and psychotropic substances in various objects (syrups, ointments, tablets, herbal mixtures, etc.), the screening methanol method commonly used in the practice of customs and forensic examination and the proposed extraction method based on the use of water phase (in particular, water solutions of salts) for preliminary effective separation of analytes from matrix components was made. In extraction systems of hexane–water, hexane–aqueous solutions of inorganic salts (sodium chloride, dipotassium phosphate and potassium carbonate), chloroform–water, the method of gas chromatography – mass spectrometry was used to determine the distribution constants (P) of organic bases – narcotic drugs and psychotropic substances (N-methylephedrine, methamphetamine, amphetamine, methadone, dihydrocodeine, hydrocodone, oxycodone, ketamine, cocaine zolpidem, fentanyl, harmine, harmaline). Based on the obtained extraction characteristics of analytes and matrix components, the optimal extractants and extraction conditions, which ensure the maximum efficiency of separation of analytes and matrix components, as well as the concentration of the analyte were substantiated. The use of extraction using water and aqueous solutions of salts provides both a sharp decrease in the detection limit (from 10–3 to 10–7 mol/dm3) in comparison with the methanol method and stable working of chromatographic equipment due to the removal of thermally unstable matrix components was shown.

scholarly journals Rapid Determination of Ethylene Oxide and 75 VOCs in Ambient Air with Canister Sampling and Associated Growth Issues

Separations ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 35
Author(s):  
Jason Hoisington ◽  
Jason S. Herrington
Keyword(s):  
Ethylene Oxide ◽  
Rapid Determination ◽  
Complex Mixture ◽  
Ambient Air ◽  
Gas Chromatography Mass Spectrometry ◽  
Average Accuracy ◽  
Relative Standard ◽  
Wide Range ◽  
Us Epa

A canister-based sampling method along with preconcentrator-Gas chromatography-Mass Spectrometry (GC-MS) analysis was applied to ethylene oxide (EtO or EO) and 75 other volatile organic compounds (VOCs) in ambient air. Ambient air can contain a large variety of VOCs, and thorough analysis requires non-discriminatory sampling and a chromatographic method capable of resolving a complex mixture. Canister collection of whole air samples allows for the collection of a wide range of volatile compounds, while the simultaneous analysis of ethylene oxide and other VOCs allows for faster throughput than separate methods. The method presented is based on US EPA Method TO-15A and allows for the detection of EtO from 18 to 2500 pptv. The method has an average accuracy of 104% and precision of 13% relative standard deviation (RSD), with an instrument run time of 32 min. In addition, a link between canister cleanliness and ethylene oxide growth is observed, and potential mechanisms and cleaning strategies are addressed.

Selective electromembrane extraction and sensitive colorimetric detection of copper(II)

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Wajid Ali Khan ◽  
Muhammad Balal Arain ◽  
Hashmat Bibi ◽  
Mustafa Tuzen ◽  
Nasrullah Shah ◽  
...  
Keyword(s):  
Applied Voltage ◽  
Colorimetric Detection ◽  
Environmental Water ◽  
Selective Extraction ◽  
Effective Parameters ◽  
Relative Standard ◽  
Electromembrane Extraction ◽  
Optimized Conditions ◽  
Donor Phase

AbstractIn this study, an extremely effective electromembrane extraction (EME) method was developed for the selective extraction of Cu(II) followed by Red-Green-Blue (RGB) detection. The effective parameters optimized for the extraction efficiency of EME include applied voltage, extraction time, supported liquid membrane (SLM) composition, pH of acceptor/donor phases, and stirring rate. Under optimized conditions, Cu(II) was extracted from a 3 mL aqueous donor phase to 8 µL of 100 mM HCl acceptor solution through 1-octanol SLM using an applied voltage of 50 V for 15 min. The proposed method provides a working range of 0.1–0.75 µg·mL−1 with 0.03 µg·mL−1 limit for detection. Finally, the developed technique was applied to different environmental water samples for monitoring environmental pollution. Obtained relative recoveries were within the range of 93–106%. The relative standard deviation (RSD) and enhancement factor (EF) were found to be ≤4.8% and 100 respectively. We hope that this method can be introduced for quantitative determination of Cu(II) as a fast, simple, portable, inexpensive, effective, and precise procedure.

A Comparison of Soxhlet Extraction and Ultrasonic-Assisted Extraction for Analysis of Photoinitiators in Printed Cartonboard Food-Packaging Materials

2012 ◽  
Vol 262 ◽  
pp. 561-566
Author(s):  
Chao Ding ◽  
Fang Wang ◽  
Mei Xia Pang ◽  
Xin Xin Yi ◽  
Feng Tan ◽  
...  
Keyword(s):  
Food Packaging ◽  
Soxhlet Extraction ◽  
Gas Chromatography Mass Spectrometry ◽  
Packaging Materials ◽  
Selected Ion Monitoring ◽  
Food Packaging Materials ◽  
Assisted Extraction ◽  
Relative Standard ◽  
Ultrasonic Assisted ◽  
Phenyl Ketone

A new method was established for detecting a series of photoinitiators (PIs) in printed cartonboard food-packaging materials, which were benzophenone (BP), 4-methylbenzophenone (MBP), 1-hydroxycyclohexyl phenyl ketone (Irgacure184), ethyl-4-dimethylaminobenzoate (EDAB), 2-ethylhexyl-4-dimethylaminobenzoate (EHDAB) and 2-isopropylthioxanthone (ITX) by gas chromatography–mass spectrometry (GC/MS). Extraction was carried out with ethyl acetate by ultrasonic solvent extraction. Samples were analyzed by GC/MS in selected ion monitoring (SIM) mode. The results indicated that six kinds of PIs had good linear relations (R2>0.9989) in the range of 10~200 μg/L. Limit of Detections (LODs) and Limit of Quantifications ( LOQs ) of all kinds of PIs were 0.3~2.6 μg /kg and 1~8 μg/kg, respectively. The recoveries of six kinds of PIs at three kinds of concentrations researched (0.30 μg/kg, 0.60 μg/ kg, 1.0 μg/kg) were ranging from 66.7%~89.4%, with the Relative Standard Deviation (RSD) of 4.2%~10.6% (n=6). The results also suggested that PIs were detected in food packaging materials.

scholarly journals EXPERT RESEARCH OF MICROQUANTITIES NARCOTIC, PSYCHOTROPIC SUBSTANCES AND PRECURSORS

2018 ◽  
Vol 18 ◽  
pp. 332-351
Author(s):  
N. Sh. Khalilova ◽  
N. V. Korableva ◽  
V. A. Vetrova ◽  
M. U. Abdullayeva ◽  
Z. U. Usmonaliyeva
Keyword(s):  
High Performance ◽  
Gas Chromatography Mass Spectrometry ◽  
Criminal Cases ◽  
Psychotropic Substances ◽  
Low Concentrations ◽  
Mass Spectrometric Detector ◽  
Sensitivity And Selectivity ◽  
Examination Methods ◽  
Active Substances ◽  
Narcotic Drugs

While investigating and prosecuting criminal cases related to illegal drug trade, psychotropic substances and precursors, microobjects found at the scene of crime, as well as on items related to a crime and its participants, assume ever greater evidentiary. In expert practice, narcotic drugs and psychotropic substances often appear as research objects, that are rarely individual compounds. At that greatest difficulties arise while research of substances that are multicomponent systems and mixtures containing a large number of impurity and ballast substances, as well as low concentrations of active substances. So it is difficult to identify the substance that served as the basis for developing a methodology for the investigation of microquantities of narcotic drugs, psychotropic substances and precursors. Despite the fact that chromatographic analysis is the most common method for the analysis of narcotic drugs, psychotropic substances and precursors, currently due to high information content, sensitivity and selectivity in the world practice of forensic chemical and medical examination, methods of gas chromatography-mass spectrometry (GC-MS) and high performance liquid chromatography with mass spectrometric detector (HPLC-MS) become one of the most widely used. The use of the HPLC-MS method is the most optimal while research on narcotic, psychotropic substances and precursors by reducing the time of sample preparation, since there is no need for the stage of reagents evaporation and receipt of derivatives, and also it is appear possible to identify non-volatile substances that cannot be analyzed by GC-MS. As a result of the performed researches a methods for the criminalistic research of microquantities of certain narcotic drugs (heroin, morphine, opium, methamphetamine, cocaine, etc.), psychotropic substances (clonidine, bromazepam, ketazolam, trihexyphenidyl, methaqualone, barbital, etc.), precursors (pseudoephedrine, ephedrine) and a poison such as scopolamine using GC-MS and HPLC-MS.

scholarly journals Determination of multi-class herbicides in soil by liquid-solid extraction coupled with headspace solid phase microextraction method

2016 ◽  
Vol 81 (8) ◽  
pp. 923-934 ◽  
Author(s):  
Rada Djurovic-Pejcev ◽  
Tijana Djordjevic ◽  
Vojislava Bursic
Keyword(s):  
Solid Phase Microextraction ◽  
Solid Phase ◽  
Soil Samples ◽  
Gas Chromatography Mass Spectrometry ◽  
Optimum Number ◽  
Polydimethyl Siloxane ◽  
Headspace Solid Phase Microextraction ◽  
Relative Standard ◽  
Detection And Quantification

A method is described for simultaneous determination of five herbicides (metribuzin, acetochlor, clomazone, oxyfluorfen and dimethenamid) belonging to different pesticides groups in soil samples. Developed headspace solid phase microextraction method (HS-SPME) in combination with liquid-solid sample preparation (LS) was optimized and applied in the analysis of some agricultural samples. Optimization of microextraction conditions, such as temperature, extraction time and sodium chloride (NaCl) content was perfor-med using 100 ?m polydimethyl-siloxane (PDMS) fiber. The extraction effi-ciencies of methanol, methanol:acetone=1:1 and methanol:acetone:hexane= =2:2:1 and the optimum number of extraction steps during the sample prepa-ration, were tested, as well. Gas chromatography-mass spectrometry (GC-MS) was used for detection and quantification, obtaining relative standard deviation (RSD) below 13%, and recovery values higher than 83% for multiple analyses of soil samples fortified at 30 ?g kg-1 of each herbicide. Limits of detection (LOD) were less than 1.2 ?g kg-1 for all the studied herbicides.

Liquid Chromatographic Determination of Glyphosate and Aminomethylphosphonic Acid (AMPA) in Environmental Water: Collaborative Study

1991 ◽  
Vol 74 (2) ◽  
pp. 317-323 ◽  
Author(s):  
Mark E Oppenhuizen ◽  
John E Cowell
Keyword(s):  
Collaborative Study ◽  
Chromatographic Determination ◽  
Environmental Water ◽  
Aminomethylphosphonic Acid ◽  
Relative Standard ◽  
Total Variability ◽  
Liquid Chromatographic Determination ◽  
Predicted Values ◽  
Liquid Chromatographic

Abstract A new method for determination of glyphosate and amlnomethylphosphonlc acid (AMPA) residues In environmental water was collaboratively studied by 6 laboratories. The method Is simpler and shorter than previous methods. A filtered volume of water is evaporated to dryness and the residue Is dissolved In a buffered EDTA solution. Glyphosate and AMPA are determined by liquid chromatography with postcolumn reaction detection. The method was validated over the range 0.50-5000 ppb, although one of the collaborating laboratories could not reliably quantltate below 1.0 ppb. Statistical analysis of the results showed that typical reproducibility relative standard deviations (RSDR) ranged from 11 to 20% for both glyphosate and AMPA, which compares very well with predicted values for this concentration range. Total variability (as measured by sR) Increased with increasing fortification level. The method has been adopted official first action by AOAC.

Gas Chromatographic Determination of Low Levels of Di-(2-ethylh exyl)phthalate in Soy Oil

1973 ◽  
Vol 56 (1) ◽  
pp. 181-183
Author(s):  
D T Williams
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Chromatographic Determination ◽  
Phthalate Ester ◽  
Gas Chromatography Mass Spectrometry ◽  
Soy Oil ◽  
Chromatography Mass Spectrometry ◽  
Cleanup Procedure ◽  
Layer Chromatography ◽  
Ethylhexyl Phthalate

Abstract Di-(2-ethylhexyl)phthalate can be determined by gas chromatography at a level of 0.3 ppm in soy oil. A cleanup procedure involving epoxidation of soy oil residues with m-chloroperbenzoic acid allows confirmation of the phthalate ester by thin layer chromatography-mass spectrometry or gas chromatography-mass spectrometry.

Application of cup-shaped trilactams for selective extraction of volatile compounds by gas chromatography-mass spectrometry

The Analyst ◽  
2020 ◽  
Vol 145 (20) ◽  
pp. 6668-6676
Author(s):  
Sitanan Sartyoungkul ◽  
Isaya Thaveesangsakulthai ◽  
Mark Kristan Espejo Cabello ◽  
Chadin Kulsing ◽  
Hidehiro Sakurai
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Liquid Phase ◽  
Volatile Compounds ◽  
Organic Compounds ◽  
Chiral Recognition ◽  
Selective Extraction ◽  
Gas Chromatography Mass Spectrometry ◽  
Phase Extraction ◽  
Volatile Organic

Chiral cup-shaped trilactams were used as liquid phase extraction material of volatile organic compounds in perfume analyzed by SPME GC-MS. (+)-material showed higher selective chiral recognition with oxygenated and cyclic volatile compounds.

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