Effect of Extraction Procedure and Gas Chromatography Temperature Program on Discrimination of MDMA Exhibits

2013 ◽  
Vol 59 (2) ◽  
pp. 327-336 ◽  
Author(s):  
Karlie M. McManaman ◽  
Ruth Waddell Smith
Keyword(s):  
Gas Chromatography ◽  
Extraction Procedure ◽  
Temperature Program

Pesticides Analysis in Beans by Gas Chromatography Couplet with Tandem Mass Spectrometry

2021 ◽  
Vol 6 (4) ◽  
Author(s):  
Mizutani G ◽  
◽  
Bustillos O ◽  
Keyword(s):  
Gas Chromatography ◽  
Analytical Method ◽  
Extraction Procedure ◽  
Quadrupole Mass ◽  
Triple Quadrupole Mass Spectrometer ◽  
Mineral Salts ◽  
Pesticides Residues ◽  
Solid Liquid ◽  
Validation Of Analytical Method ◽  
Iron And Calcium

Beans are part of the basic diet alimentation for Brazilian population, as they gather proteins, carbohydrates, vitamins, mineral salts, fibers, amino acids and essential nutrients such as iron and calcium, being a complete food that can be compared with the amount of protein that the meat has. Considering the beans world production, in development countries represent almost 50%, being that Myanmar, India and Brazil the top three position. The use of pesticides is widely spread in these countries to reduce agricultural losses due to pests that interfere with grain production. Therefore the risk that could be generated from foods pesticides residues makes their analyses of quantification mandatory. The purpose of this work was to develop an analytical method to quantitatively characterize fungicides pesticides residues, flutriafol, procymidone and tebuconazole that were used to angular spot control, anthracnose, rust and alternaria spot, white mold fungi, present in beans, by means of gas chromatography coupled with a triple quadrupole mass spectrometer. Samples of beans, Phaseolus vulgaris L, types white, black, string and Vigna angularis, type adzuki, had been bought in grains store and supermarkets at metropolitan São Paulo city. The validation of analytical method was explored for sensitivity, selectivity, precision. The extraction procedure was performed in two different forms, QuEChERS, and solid-liquid extraction with low temperature. Through this methodology, reached below the maximum limit allowed by Brazilian law 0.5mgkg-1 for procymidone and 0.1mgkg-1 for flutriafol and tebuconazole. Several samples of four types of beans were tested and all of them had procymidone identified and 7% of samples higher than the law limit.

scholarly journals Pesticidal residue analysis and phytochemical screening in leaves and roots of Barleria prionitis Linn.

2018 ◽  
Vol 8 (5) ◽  
pp. 455-459
Author(s):  
Reema Dheer ◽  
Surendra Swarnkar
Keyword(s):  
Gas Chromatography ◽  
Organochlorine Pesticides ◽  
Pesticide Residues ◽  
Capillary Column ◽  
Residue Analysis ◽  
Extraction Procedure ◽  
Water Soluble ◽  
Phytochemical Screening ◽  
Plant Materials ◽  
Leaves And Roots

In the present study emphasize on phytochemical screening in leaves and roots of Barleria prionitis Linn. The extract of plant materials total ash content, extractive value, water soluble ash, and loss on drying values were identified. Medicinal plant materials are liable to contain pesticide residues, which accumulate from agriculture practices, such as spraying, treatment of soils during cultivation and administration of fumigants during storage. It is therefore recommended that every sample of medicinal plants used for such type of studies should be analyzed for the pesticidal residues. Therefore in the present study parts of the herb used for their antidiabetic potential were analyzed for organochlorine pesticides, which are persistent and remain in the food chain for longer periods. The samples of leaf and root of Barleria prionitis were ground coarsely and then preceded for the extraction procedure. The sample of extracts were analysed for residues of organochlorine pesticides by Gas Chromatography (GC). Analysis were carried out on a Schimadzu Model 2010 Gas Chromatograph (GC) equipped with 63 NI electron capture detector (ECD) and a capillary column HP ultra 2. The instrument was supported by Lab Solution software. The pesticide residues detected in them in the GC were within the limits. For phytochemical screening, the ethanolic and hydroalcoholic extracts obtained were prepared and subjected to various qualitative tests in order to reveal the presence or absence of common phytopharmaceuticals by using standard tests. Keywords: Phytochemical screening, Pesticidal residues, Barleria prionitis Gas Chromatography, Ash value, extractive value.

Steroids in equine testes: the identification of endogenous 19-hydroxy and 19-nor neutral steroids by gas chromatography–mass spectrometry

1989 ◽  
Vol 120 (2) ◽  
pp. 223-229 ◽  
Author(s):  
M. C. Dumasia ◽  
E. Houghton ◽  
M. Jackiw
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Aldol Reaction ◽  
Extraction Procedure ◽  
Testicular Tissue ◽  
Enzyme Hydrolysis ◽  
Gas Chromatography Mass Spectrometry ◽  
Chromatography Mass Spectrometry ◽  
Trimethylsilyl Ethers ◽  
Conjugated Steroids

ABSTRACT After homogenization of testicular tissue from stallions aged 1, 2 and 5 years, the unconjugated and conjugated steroids were isolated by a combined solvent–solid extraction procedure. The conjugates were further separated into glucuronides and sulphates by chromatography using Sephadex LH-20. After enzyme hydrolysis and solvolysis of the respective conjugate classes, the three extracts, unconjugated steroids, aglycones and solvolysed sulphates, were purified by chromatography using Kieselgel 60H columns. Five fractions were resolved from each extract; an aliquot of each fraction was derivatized to form the methoxime-trimethylsilyl ethers and the steroids were identified by combined gas chromatography–mass spectrometry. The results have shown that in stallion testes (1) steroidogenesis proceeds by both the 4-ene and the 5-ene pathways, (2) age-linked changes occur in both unconjugated and sulphoconjugated steroid fractions and (3) 19-hydroxy androgens and the 19-nor (C18) neutral steroids (19-norandrostenedione and 19-nortestosterone) are detected only in the unconjugated fraction whereas oestrone, the isomers of oestradiol and of 5(10)-oestrene-3,17-diol are the only steroids detected in the sulphoconjugate fraction. It is suggested that the unconjugated 19-oxygenated androgens present in stallion testes are converted to 19-nor neutral steroids by a reverse aldol reaction and a mechanism showing the putative intermediates in their formation is illustrated. Journal of Endocrinology (1989) 120, 223–229

Determination of Chlorbenside Residues Including Its Sulfoxide and Sulfone Oxidation Products

1966 ◽  
Vol 49 (2) ◽  
pp. 407-412
Author(s):  
Harry Shuman ◽  
Ugo R Cieri
Keyword(s):  
Gas Chromatography ◽  
Acetic Acid ◽  
Acid Solution ◽  
Aluminum Oxide ◽  
Electron Capture ◽  
Acetic Acid Solution ◽  
Extraction Procedure ◽  
Oxidation Products ◽  
Aluminum Oxide Column

Abstract A method is presented for determining residues of chlorbenside including its sulfoxide and sulfone oxidation products. The method employs the Mills-Onley-Gaither extraction procedure. Chlorbenside and chlorbenside sulfoxide are converted to chlorbenside sulfone by a short oxidation with chromic-acetic acid solution. Chlorbenside sulfone is isolated from interfering pesticides and most oxidation products on an aluminum oxide column and determined by electron capture gas chromatography. Recoveries for mixtures of the three components added to apple samples at 0.3–5 ppm (calculated as chlorbenside) were between 92 and 110%.

scholarly journals Determination of Spiroxamine Residues in Grapes, Must, and Wine by Gas Chromatography/Ion Trap-Mass Spectrometry

2005 ◽  
Vol 88 (6) ◽  
pp. 1834-1839 ◽  
Author(s):  
Nicholas G Tsiropoulos ◽  
Konstantinos Liapis ◽  
Dimitrios T Likas ◽  
George E Miliadis
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Ion Trap ◽  
Extraction Procedure ◽  
Ion Trap Mass Spectrometry ◽  
Limit Of Quantification ◽  
Analytical Methodology ◽  
White Wines ◽  
Relative Standard

Abstract Analytical methodology was developed and validated for the determination of spiroxamine residues in grapes, must, and wine by gas chromatography/ion trap-mass spectrometry (GC/IT-MS). Two extraction procedures were used: the first involved grapes, must, and wine extraction with alkaline cyclohexane–dichloromethane (9 + 1, v/v) solution, and the second grape extraction with acetone, dichloromethane, and petroleum ether. In both procedures, the extract was centrifuged, evaporated to dryness, and reconstituted in cyclohexane or 2,2,4-trimethylpentane–toluene (9 + 1, v/v), respectively. Spiroxamine diastereomers A and B were determined by GC/IT-MS, and a matrix effect was observed in the case of grapes but not in must and wine. Recovery of spiroxamine from fortified samples at 0.02 to 5.0 mg/kg ranged from 78–102% for grapes and must, with relative standard deviation (RSD) <13%; for red and white wines, recoveries ranged from 90 to 101% with RSD <9%. The limit of quantification was 0.02 mg/kg for grapes, must, and wine or 0.10 mg/kg for grapes, depending on the extraction procedure used.

scholarly journals Method for the determination of concentration and stable carbon isotope ratios of atmospheric phenols

2013 ◽  
Vol 6 (11) ◽  
pp. 2965-2974 ◽  
Author(s):  
M. Saccon ◽  
R. Busca ◽  
C. Facca ◽  
L. Huang ◽  
S. Irei ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Isotopic Composition ◽  
Isotope Ratio ◽  
Extraction Procedure ◽  
Carbon Isotopic Composition ◽  
Stable Carbon ◽  
Concentration Measurements ◽  
Isotope Ratio Measurements

Abstract. A method for the determination of the stable carbon isotopic composition of atmospheric nitrophenols in the gas and particulate phases is presented. It has been proposed to use the combination of concentration and isotope ratio measurements of precursor and product to test the applicability of results of laboratory studies to the atmosphere. Nitrophenols are suspected to be secondary products formed specifically from the photooxidation of volatile organic compounds. XAD-4TM resin was used as an adsorbent on quartz filters to sample ambient phenols using conventional high volume air samplers at York University in Toronto, Canada. Filters were extracted in acetonitrile, with a HPLC (high-performance liquid chromatography) clean-up step and a solid phase extraction step prior to derivatization with BSTFA (bis(trimethylsilyl) trifluoroacetamide). Concentration measurements were done with gas chromatography–mass spectrometry and gas chromatography–isotope ratio mass spectrometry was used for isotope ratio analysis. The technique presented allows for atmospheric compound-specific isotopic composition measurements for five semi-volatile phenols with an estimated accuracy of 0.3–0.5‰ at atmospheric concentrations exceeding 0.1 ng m−3 while the detection limits for concentration measurements are in the pg m−3 range. Isotopic fractionation throughout the entire extraction procedure and analysis was proven to be below the precision of the isotope ratio measurements. The method was tested by conducting ambient measurements from September to December 2011.

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