scholarly journals Concentration of Organotin and Booster Biocides in Sediments of Seagrass Area from Sungai Pulai Estuary, South of Johor, Malaysia

Environments ◽  
2019 ◽  
Vol 6 (2) ◽  
pp. 26 ◽  
Author(s):  
Aqilah Mukhtar ◽  
Ferdaus Mohamat-Yusuff ◽  
Syaizwan Zulkifli ◽  
Hiroya Harino ◽  
Ahmad Ismail ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Extraction Procedure ◽  
Gas Chromatography Mass Spectrometry ◽  
Seagrass Bed ◽  
Antifouling Paints ◽  
Sediment Samples ◽  
Painted Surface ◽  
Ship Hulls ◽  
Fouling Organisms

Antifouling compounds are widely used in paints applied on ship hulls to prevent attachment of fouling organisms. However, a certain amount of these chemicals could leach from the painted surface, enter seawater, and pose deleterious effects on various marine biotas. The present study aimed to determine the concentration of organotin (OT) compounds and booster biocides in sediments collected from the seagrass area of Sungai Pulai estuary, Malaysia. The sediment samples were collected from three points on the seagrass bed, brought back to the laboratory, extracted using standard extraction procedure, and the analytes were analysed using gas chromatography-mass spectrometry (GC-MS) method. The results showed that tributyltin (TBT) concentrations in sediments were within the range of 8.1 ± 0.4 to 10.6 ± 0.5 µg/kg, whereas the values of triphenyltin (TPT) were between 17.1 ± 0.9 and 19.4 ± 1.0 µg/kg. The range of concentration of booster biocides, namely diuron, dichlofluanid chlorothalonil, Irgarol 1051, M1, and Sea-Nine 211, were from <0.1 to 22.9 ± 1.1, 48.7 ± 2.4 to 800 ± 40, <0.1 to 6.2 ± 0.3, <0.1 to 1.4 ± 0.1, 44 ± 2.2 to 877 ± 44, and 9.1 ± 0.5 to 170 ± 8.5 µg/kg, respectively. The concentration of organotin was much lower than the previous study conducted in southern Johor. Meanwhile, the increased concentration of booster biocides proves the use of these compounds as antifouling paints in shipping systems nowadays.

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

scholarly journals Thin Layer Chromatography Convulsant Screen Extended by Gas Chromatography-Mass Spectrometry

2003 ◽  
Vol 15 (1) ◽  
pp. 42-45 ◽  
Author(s):  
W. Emmett Braselton ◽  
Malgorzata Johnson
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Thin Layer ◽  
Drugs Of Abuse ◽  
Extraction Procedure ◽  
Stomach Contents ◽  
Gas Chromatography Mass Spectrometry ◽  
Organic Fraction ◽  
Aqueous Fraction ◽  
Chromatography Mass Spectrometry

Acute onset convulsive disorders in the canine may result from exposure to a variety of toxicants including strychnine, insecticides, metaldehyde, zinc phosphide, methylxanthines, drugs of abuse, bromethalin, and the tremorgenic mycotoxins (roquefortine and penitrem A). Although several of the above can be identified in a single gas chromatography-mass spectrometry (GC-MS) screen most have to be determined by separate tests. This report describes a modification of the strychnine extraction procedure, which allows thin layer chromatographic (TLC) identification of strychnine, bromethalin, roquefortine, and penitrem A in suspect baits, stomach contents or vomitus, and extends the identification to a wide variety of drugs, pesticides, and environmental contaminants by GC-MS. Samples were mixed with base, extracted into CH2Cl2 and the organic fraction back-extracted with acid. The organic fraction (neutrals) was purified by gel permeation chromatography (GPC) and analyzed by TLC to determine penitrem A and bromethalin. The acidic aqueous fraction was adjusted to pH > 9 and extracted into CH2Cl2. The resulting CH2Cl2 layer (bases) was then analyzed by TLC to determine strychnine and roquefortine. The organic basic and neutral fractions were recombined with a late eluting GPC fraction and analyzed by GC-MS. Of 312 samples analyzed by TLC from 1995 to 2001, 35 were positive for strychnine alone, 58 were positive for both roquefortine and penitrem A, 4 were positive for roquefortine alone, and 1 was positive for bromethalin. None of the samples were positive for penitrem A alone. Samples negative by TLC were analyzed by the GC-MS extended procedure since mid-1999, and 14 have shown positive for a wide variety of compounds with convulsant activity.

Relationship between biomarkers and iron speciation and their environmental significance in plateau subsidence lacus: an example of Luguhu Lake, southeastern Tibetan Plateau

2020 ◽  
Vol 111 (4) ◽  
pp. 259-266
Author(s):  
Zixiang WANG ◽  
Lina SUN
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Tibetan Plateau ◽  
Gas Chromatography Mass Spectrometry ◽  
Total Absorption ◽  
Environmental Significance ◽  
Strong Negative Correlation ◽  
Sediment Samples ◽  
Absorption Area ◽  
Fe Speciation

ABSTRACTHerein, we present a synthetic study combining iron (Fe) speciation and biomarkers in sediment samples from Luguhu Lake to investigate their relationship and the environmental significance thereof. Mössbauer spectroscopy and gas chromatography–mass spectrometry were used for these measurements. The results suggest that (a) there is a strong negative correlation between Fe2+/Fe3+ and the ratio of pristane to phytane (Pr/Ph), indicating that both Fe2+/Fe3+ and Pr/Ph effectively present the inorganic and organic aspects, respectively, of the oxidation–deoxidation environment in Luguhu Lake; (b) palaeotemperature may be a factor, in addition to the redox conditions, that affects the Fe2+/Fe3+ ratio, and it might play a favourable role in studies of palaeotemperature; and (c) the relative abundance of Fe in Luguhu Lake is affected by the palaeoclimate and the environment in which the palaeosediment was deposited. The mechanism of change in the total area (the total absorption area of Mössbauer spectrum) with the palaeoenvironment seems to be explained by the loss of Fe, which occurs as the water drains out of the lake, and the increase in Fe loss from the sediment as rainfall levels increase.

scholarly journals Optimization of Solid-Phase Microextraction for the Gas Chromatography/Mass Spectrometry Analysis of Persistent Organic Pollutants

2004 ◽  
Vol 87 (4) ◽  
pp. 1021-1027 ◽  
Author(s):  
Ana Gago-Martínez ◽  
María J Nogueiras ◽  
Sandra Rellán ◽  
Juan Prado ◽  
María F Alpendurada ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Polybrominated Diphenyl Ethers ◽  
Solid Phase Microextraction ◽  
Solid Phase ◽  
Extraction Procedure ◽  
Mass Spectrometry Analysis ◽  
Gas Chromatography Mass Spectrometry ◽  
Chromatography Mass Spectrometry ◽  
Relative Standard

Abstract In this work, solid-phase microextraction (SPME) has been applied as an alternative for the selective extraction of 3 polybrominated diphenyl ethers (PBDEs), 2,2′,4,4′-tetrabromodiphenyl ether (PBDE-47); 2,2′,4,4′,5-pentabromodiphenyl ether (PBDE-99); and 2,2′,4,4′,6-pentabromodiphenyl ether (PBDE-100), and 2 alkylphenols, 4-tert-OP and 4-NP, prior to their analysis by gas chromatography/mass spectrometry (GC/MS). The advantages of this technique are mainly its simplicity, cost-effectiveness, and time-saving sample preparation, as well as being a solvent-free technique. With the aim of optimizing the conditions for an efficient extraction of the studied compounds, different fiber coatings and the main parameters affecting the extraction procedure have been evaluated. The results obtained showed a good linearity in the range of concentrations investigated, and adequate relative standard deviation values were found according to the range accepted for SPME. Recovery values were in the range of 78–108%, and good detection and quantitation limits at ppt levels were obtained for both methods, allowing the determination of the selected compounds in samples at trace levels. The results obtained clearly show the potential of SPME for efficient concentration of the target compounds and also demonstrate the reliability of this extraction technique for their GC/MS analysis.

Simultaneous Determination of Eight Sympathomimetic Amines in Urine by Gas Chromatography/Mass Spectrometry

2010 ◽  
Vol 93 (1) ◽  
pp. 116-122 ◽  
Author(s):  
Michael Moawad ◽  
Cheang S Khoo ◽  
Samiuela Lee ◽  
James R Hennell
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Extraction Procedure ◽  
Internal Standard ◽  
Gas Chromatography Mass Spectrometry ◽  
Organic Layer ◽  
Sympathomimetic Amines ◽  
Alkaline Urine ◽  
Ms Analysis

Abstract A GC method was developed for the identification and quantitation of eight sympathomimetic amines in urine, i.e., amphetamine, methamphetamine, mephentermine, ephedrine, pseudoephedrine, methylenedioxyamphetamine, methylenedioxymethamphetamine, and methylenedioxyethylamphetamine. Methoxyphenamine was used as the internal standard (IS). The assay is rapid, sensitive, and simple to perform. It involves a liquidliquid extraction procedure with simultaneous in-solution derivatization of the organic layer with pentafluorobenzoyl chloride (PFB-Cl), followed by GC/MS analysis. These derivatives and the IS were extracted from 1 mL alkaline urine into hexane before derivatization with PFB-Cl. The organic layer was then removed and evaporated to dryness before dissolution with hexane for GC/MS analysis. Calibration curves for each analyte showed linearity in the range of 255000 ng/mL (r2 ≥ 0.997). Recoveries ranged from 88 to 99, with the precision of recoveries typically ≤5%. The LOD values ranged from 7 to 28 ng/mL, and the LOQ values ranged from 23 to 94 ng/mL. At least four ions were available for each analyte for confirmation of identity by MS.

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