scholarly journals 50 chemical exposures of concern discovered using wearable passive samplers and gas chromatography high-resolution mass spectrometry in South African children

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Jeremy P. Koelmel ◽  
Elizabeth Z. Lin ◽  
Kayley Delay ◽  
Antony J. Williams ◽  
Yakun Zhou ◽  
...  
2021 ◽  
Author(s):  
Jeremy P. Koelmel ◽  
Elizabeth Z. Lin ◽  
Kayley DeLay ◽  
Antony J. Williams ◽  
Yakun Zhou ◽  
...  

Abstract Children in low- and middle-income countries are often exposed to higher levels of, and more vulnerable to, the health effects of air pollution. Little is known about the diversity, toxicity, and dynamics of airborne chemical exposures at the molecular level. We developed a workflow employing state-of-the-art wearable passive sampling technology coupled with high-resolution mass spectrometry to comprehensively measure 147 children’s personal exposures to airborne chemicals in Limpopo, South Africa, as part of the VHEMBE study. 637 environmental exposures were detected, many of which have never been measured in this population, including 50 airborne chemical exposures of concern in the children, including biocides, plasticizers, organophosphates, dyes, combustion products, and perfumes. Biocides detected in wristbands included p,p'-DDT, p,p'-DDD, p,p'-DDE, propoxur, piperonyl butoxide, and triclosan. 27% of exposures were significantly different across seasons. Our study provides the first report covering hundreds of chemical exposures among African children, demonstrating chemical exposures warranting further study.


Author(s):  
Verónica Castro ◽  
José Benito Quintana ◽  
Javier López-Vázquez ◽  
Nieves Carro ◽  
Julio Cobas ◽  
...  

Abstract This work presents an optimized gas chromatography–electron ionization–high-resolution mass spectrometry (GC-EI-HRMS) screening method. Different method parameters affecting data processing with the Agilent Unknowns Analysis SureMass deconvolution software were optimized in order to achieve the best compromise between false positives and false negatives. To this end, an accurate-mass library of 26 model compounds was created. Then, five replicates of mussel extracts were spiked with a mixture of these 26 compounds at two concentration levels (10 and 100 ng/g dry weight in mussel, 50 and 500 ng/mL in extract) and injected in the GC-EI-HRMS system. The results of these experiments showed that accurate mass tolerance and pure weight factor (combination of reverse-forward library search) are the most critical factors. The validation of the developed method afforded screening detection limits in the 2.5–5 ng range for passive sampler extracts and 1–2 ng/g for mussel sample extracts, and limits of quantification in the 0.6–3.2 ng and 0.1–1.8 ng/g range, for the same type of samples, respectively, for 17 model analytes. Once the method was optimized, an accurate-mass HRMS library, containing retention indexes, with ca. 355 spectra of derivatized and non-derivatized compounds was generated. This library (freely available at https://doi.org/10.5281/zenodo.5647960), together with a modified Agilent Pesticides Library of over 800 compounds, was applied to the screening of passive samplers, both of polydimethylsiloxane and polar chemical integrative samplers (POCIS), and mussel samples collected in Galicia (NW Spain), where a total of 75 chemicals could be identified.


1983 ◽  
Vol 29 (4) ◽  
pp. 677-680 ◽  
Author(s):  
S J Gaskell ◽  
B G Brownsey

Abstract We describe a new, highly selective procedure for the determination of estradiol-17 beta in plasma. Samples are extracted with a micro-cellulose-coupled antiserum to estradiol-17 beta. Conversion of the extracted steroid to the bis(trimethylsilyl) ether is followed by gas chromatography/high-resolution mass spectrometry with selected ion monitoring. Precise quantification is achieved through the use of [2H3]estradiol-17 beta as internal standard.


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