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Ahram Yi,Jun Hyung Lee,Gahyun Yoo,Hye Jin Lim,Euna Park,Jungsun Han,Geun Young Kim,Sung-Eun Cho,Sang Gon Lee,Eun Hee Lee 대한임상검사정도관리협회 2021 Journal of Laboratory Medicine And Quality Assuran Vol.43 No.3
We validated a gas chromatography-mass spectrometry (GC-MS) method for quantifying pristanic acid (PrA) and phytanic acid (PhA) in plasma specimens. We developed a GC-MS method based on the analysis of 20 μM 2H3-pristanic acid (PrA-IS) and 80 μM 2H3-phytanic acid (PhA-IS) as internal standards. The GC-MS was fitted with a 30 m×0.25 mm×0.25 μm HP-5MS (Agilent, USA) column. The mass spectrometer was operated through the transitions from the precursor to the product ions (m/z [mass-to-charge ratio] 355, 369, 358, and 372 for PrA, PhA, PrA-IS, and PhA-IS, respectively). The retention times of PrA, PhA, PrA-IS, and PhA-IS were 19.33, 20.39, 19.31, and 20.38 minutes in a 26.83-minute analysis, respectively. Linearity, recovery, precision, and carryover were evaluated to validate the method. The GC-MS method yielded a linear response from 0.032 to 9.951 μmol/L for PrA (R 2=0.9999) and from 0.127 to 39.432 μmol/L for PhA (R 2=0.9998). The limits of quantification by the methods were 0.032 μmol/L for PrA and 0.127 μmol/L for PhA. The recovery of PrA and PhA GC-MS method measurements were within ±10% when evaluated with external quality assessment materials. The within-batch and total coefficients of variation were all below 6% for both PrA and PhA test results. Twenty-interday imprecision (%) were all below 5% for both PrA and PhA test results. Carry-over was found to be 0.001% for PrA and –0.008% for PhA. The GC-MS PrA and PhA assay showed adequate recovery, precision, sensitivity, and linearity. Hence, it is suitable for routine clinical work.
최지원(Jiwon Choi),홍형진(Hyungjin Hong),이정섭(Jeongsub Lee),유주희(Juhee Yoo),박보람(Boram Park),김가현(Gahyun Kim),윤성원(Sungwon Yoon),이철민(Cheolmin Lee) 한국환경보건학회 2021 한국환경보건학회지 Vol.47 No.4
Background: This study was conducted to provide background information for the proper management of radon contamination in apartments using mechanical ventilation facilities in residential environments. Objectives: To this end, this study compared and evaluated changes in radon concentrations based on different operating intensities of mechanical ventilation with or without natural ventilation. Methods: For the continuous measurement of radon concentrations, an RAD7 instrument was installed in four apartments equipped with a ventilation system. The measurements were done for comparison of ventilation types and different ventilation intensities (“high”, “middle”, “low”). Results: The results confirmed that both mechanical and natural ventilation sufficiently reduced the radon concentration in the apartments. In particular, mechanical ventilation at “high” intensity was the most effective. Natural ventilation combined with mechanical ventilation and then natural ventilation alone were the second and the third most effective, respectively. Conclusions: When using ventilation to reduce indoor radon concentrations, it is most effective to operate mechanical ventilation (“high”) or natural ventilation and mechanical ventilation at the same time. In cases where mechanical ventilation is available alone, it is recommended to operate it at a minimum of “middle” intensity.