In this paper, a new headspace gas chromatography (HSGC) method has been developed for the determination of ethylene oxide (EO) and 1,4-Dioxane (Dioxane) in bulk lots of polyethylene glycols (PEG). PEG samples are dissolved in dimethyl sulfoxide, heated in a headspace oven maintained at 90°C for 10 min and then injected into the GC system for analysis. Analytes are separated through a thermal gradient elution from 36 to 240°C on an Agilent DB-624 column (60 m × 0.53 mm diameter, film thickness 3.00 μm). The carrier gas is helium and detector is flame ionization detector. Total run time of the new HSGC method is about 18 min. In the new HSGC method, other common residual solvents present in PEGs such as methanol (MeOH), methyl formate (MF) and acetyl aldehyde (Acetal) are also sufficiently separated from EO and Dioxane peaks. In the HSGC methods prescribed in USP monograph <228> and EP monograph <2.4.25>, EO co-elutes with MF. The new HSGC method was successfully validated according to current ICH/VICH guidelines and was found to be specific, linear, accurate, precise, robust and sensitive. This HSGC method is fast and quality control (QC) friendly and suitable for routine analysis for the determination of EO and Dioxane in bulk batches of PEGs in QC laboratories.
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http://dx.doi.org/10.1093/chromsci/bmaf011 | DOI Listing |
Anticancer Res
March 2025
Department of Radiation Oncology, Osaka University Graduate School of Medicine, Osaka, Japan.
Background/aim: Ultra-high dose rate irradiation (uHDR) (>40 Gy/s), commonly referred to as FLASH, has garnered attention in radiation therapy research due to its potential to mitigate damage to normal tissues while maintaining tumoricidal effects. Research on FLASH therapy using electron beams, X-rays, and proton beams has preceded studies using carbon ion beams. However, the clinical potential of FLASH carbon ion irradiation is increasingly being recognized, similar to other radiation modalities.
View Article and Find Full Text PDFJ Chromatogr Sci
January 2025
Global Pharmaceutical Technical Support, Boehringer Ingelheim Animal Health USA Inc., 631 US Highway 1, North Brunswick, NJ 08902, USA.
In this paper, a new headspace gas chromatography (HSGC) method has been developed for the determination of ethylene oxide (EO) and 1,4-Dioxane (Dioxane) in bulk lots of polyethylene glycols (PEG). PEG samples are dissolved in dimethyl sulfoxide, heated in a headspace oven maintained at 90°C for 10 min and then injected into the GC system for analysis. Analytes are separated through a thermal gradient elution from 36 to 240°C on an Agilent DB-624 column (60 m × 0.
View Article and Find Full Text PDFBiomed Phys Eng Express
January 2025
Division of Health Science, Osaka University Graduate School of Medicine, Osaka, Japan.
. Applying carbon ion beams, which have high linear energy transfer and low scatter within the human body, to Spatially Fractionated Radiation Therapy (SFRT) could benefit the treatment of deep-seated or radioresistant tumors. This study aims to simulate the dose distributions of spatially fractionated beams (SFB) to accurately determine the delivered dose and model the cell survival rate following SFB irradiation.
View Article and Find Full Text PDFEnviron Sci Pollut Res Int
January 2025
Departamento de Química, ICEx, Universidade Federal de Minas Gerais, Avenida Antônio Carlos, Belo Horizonte, MG, 6627, 370901, Brazil.
The development of methods for determining volatile and semi-volatile organic compounds in public spaces has become necessary to identify potential health and environmental risks. This study presents a practical methodology for sampling, extracting, detecting, and identifying these compounds in a vehicular traffic region in Belo Horizonte, Brazil. The methodology uses direct-immersion solid phase microextraction (DI-SPME) and static headspace (SHS) to extract SVOCs/VOCs.
View Article and Find Full Text PDFAnticancer Res
October 2024
Department of Radiation Oncology, Osaka University Graduate School of Medicine, Osaka, Japan.
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