Enantiomer Fractions Are Preferred to Enantiomer Ratios for Describing Chiral Signatures in Environmental Analysis

Harner, Tom; Wiberg, Karin; Norstrom, Ross J.

doi:10.1021/es9906958

Cited by 348 publications

(214 citation statements)

References 10 publications

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“…Enantiomeric fraction (EF) quantifying the stereoisomeric composition was calculated by use of a method described elsewhere [43], with slight modification:…”

Section: Enantiomeric Fractionmentioning

confidence: 99%

Enantiomeric determination of azole antifungals in wastewater and sludge by liquid chromatography–tandem mass spectrometry

et al. 2012

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A sensitive and reliable liquid chromatographictandem mass spectrometric method for enantiomeric determination of five chiral azole antifungals (econazole, ketoconazole, miconazole, tebuconazole, and propiconazole) in wastewater and sludge has been established and validated. An isotope-labeled internal standard was used for quantification. Recovery of the individual enantiomers was usually in the range of 77-102 % for wastewater and 71-95 % for sludge, with relative standard deviations within 20 %. No significant difference (p > 0.05) was observed between recovery of pairs of enantiomers of the chiral azole antifungals except for those of tebuconazole. Method quantification limits for individual enantiomers were 0.3-10 ng L −1 and 3-29 ng g −1 dry weight for wastewater and sludge, respectively. The method was used to investigate the enantiomeric composition of the azole pharmaceuticals in wastewater and sludge samples from a sewage treatment plant in China. Enantiomers of miconazole, ketoconazole, and econazole were widely detected. The results showed that the azole antifungals in wastewater and sludge were generally racemic or marginally non-racemic. The method is a useful tool for investigation of the enantiomeric occurrence, behavior, and fate of the chiral azole antifungals in the environment.

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“…Enantiomeric fraction (EF) quantifying the stereoisomeric composition was calculated by use of a method described elsewhere [43], with slight modification:…”

Section: Enantiomeric Fractionmentioning

confidence: 99%

Enantiomeric determination of azole antifungals in wastewater and sludge by liquid chromatography–tandem mass spectrometry

et al. 2012

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“…The optical rotation of the five chiral MeSO 2 -PCBs investigated in the present study is not known. The EF of the chiral MeSO 2 -PCBs is defined [33] as EF X ¼ A1=ðA1 þ A2Þ where A1 and A2 are the peak areas of the first and the second eluting enantiomers, respectively, separated by the present chiral columns. For calculation of EFs, peak areas were determined for the enantiomers when the peak heights were greater than three times the background noise.…”

Section: Enantiomeric Fractions Of Chiral Meso 2 -Pcbsmentioning

confidence: 99%

Methylsulfonyl polychlorinated biphenyls in fish from an electronic waste‐recycling site in South China: Levels, congener profiles, and chiral signatures

Zhang

Luo

et al. 2012

Enviro Toxic and Chemistry

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Abstract-Great concerns have been raised about the fate and effects of polychlorinated biphenyls (PCBs) and other organic contaminants contained in electronic waste (e-waste) exported from industrialized countries at midlatitudes to subtropical and tropical regions. Information on the metabolites of these chemicals, for example, methylsulfonyl-PCBs (MeSO 2 -PCBs) in wildlife from the later regions is scarce. In the present study, 17 MeSO 2 -PCBs, including five chiral congeners, were detected in the muscle, liver, and brain tissues of two benthic fish species-northern snakehead and mud carp-from a small pond near an electronic waste recycling site in South China. The mean concentrations of the sum of the MeSO 2 -PCBs ranged from 80 to 340 ng/g lipid weight in the tissues, with relative higher levels in the liver than the muscle and brain tissues. These levels were one order of magnitude greater than the highest levels of MeSO 2 -PCBs previously reported in fish. The 3 0 -MeSO 2 -CB 87, 3 0 -and 4 0 -MeSO 2 -CB 101, 4-MeSO 2 -CB 110, and 4-MeSO 2 -CB 149 were dominant, collectively comprising more than 55% of the total MeSO 2 -PCBs. Except for 4-MeSO 2 -

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“…The EF is used as a descriptor of chiral signatures and is defined by: EF = peak area of enantiomer 1/(peak area of enantiomer 1 + peak area of enantiomer 2), where enantiomer 1 is the first eluting enantiomer and enantiomer 2 is the last eluting enantiomer of a pair [8,31]. Thus, EF = 0.5 correlates to a racemic composition of a compound [8,9,31] …”

Section: Multidimensional Chromatographic Performancementioning

confidence: 99%

“…o,p'-DDT and its degradation product o,p'-DDD are chiral molecules (o,p'-DDE is achiral) and both exist as enantiomeric pairs (-)-o,p'-DDT and (+)-o,p'-DDT, and (-)-o,p'-DDD and (+)-o,p'-DDD [6,7]. A chiral compound is produced industrially as a racemic mixture [8]. Fresh treatment with technical DDT will have a chiral signature where enantiomers of o,p'-DDT and of o,p'-DDD are present as a 1:1 racemic mixture corresponding to an enantiomeric fraction (EF) = 0.5 [9].…”

Section: Introductionmentioning

confidence: 99%

Two multidimensional chromatographic methods for enantiomeric analysis of o,p′-DDT and o,p′-DDD in contaminated soil and air in a malaria area of South Africa

Naude

Rohwer

2012

Analytica Chimica Acta

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In rural parts of South Africa the organochlorine insecticide DDT (1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane) is still used for malaria vector control where traditional dwellings are sprayed on the inside with small quantities of technical DDT. Since o,p'-DDT may show enantioselective oestrogenicity and biodegradability, it is important to analyse enantiomers of o,p'-DDT and its chiral degradation product, o,p'-DDD, for both health and environmentalforensic considerations. Generally, chiral analysis is performed using heartcut multidimensional gas chromatography (MDGC) and, more recently, comprehensive two-dimensional gas chromatography (GC x GC). We developed an off-line gas chromatographic fraction collection (heart-cut) procedure for the selective capturing of the appropriate isomers from a first

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Enantiomer Fractions Are Preferred to Enantiomer Ratios for Describing Chiral Signatures in Environmental Analysis

Cited by 348 publications

References 10 publications

Enantiomeric determination of azole antifungals in wastewater and sludge by liquid chromatography–tandem mass spectrometry

Enantiomeric determination of azole antifungals in wastewater and sludge by liquid chromatography–tandem mass spectrometry

Methylsulfonyl polychlorinated biphenyls in fish from an electronic waste‐recycling site in South China: Levels, congener profiles, and chiral signatures

Two multidimensional chromatographic methods for enantiomeric analysis of o,p′-DDT and o,p′-DDD in contaminated soil and air in a malaria area of South Africa

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