Carter Ellison M, Jackson Mark C, Katz Lynn E, Speitel Gerald E
Department of Civil, Architectural, and Environmental Engineering, University of Texas at Austin, Cockrell School of Engineering, 1 University Station C1786, Austin, Texas 78712-1173, USA.
J Expo Sci Environ Epidemiol. 2014 May-Jun;24(3):305-10. doi: 10.1038/jes.2013.61. Epub 2013 Oct 2.
Despite long-standing awareness of adverse health effects associated with chronic human exposure to formaldehyde, this hazardous air pollutant remains a challenge to measure in indoor environments. Traditional analytical techniques evaluate formaldehyde concentrations over several hours to several days in a single location in a residence, making it difficult to characterize daily temporal and spatial variation in human exposure to formaldehyde. There is a need for portable, easy-to-use devices that are specific and sensitive to gas-phase formaldehyde over short sampling periods so that dynamic processes governing formaldehyde fate, transport, and potential remediation in indoor environments may be studied more effectively. A recently developed device couples a chemical sensor element with spectrophotometric analysis for detection and quantification of part per billion (ppbv) gas-phase formaldehyde concentrations. This study established the ability of the coupled sensor-spectrophotometric device (CSSD) to report formaldehyde concentrations accurately and continuously on a 30-min sampling cycle at low ppbv concentrations previously untested for this device in a laboratory setting. Determination of the method detection limit (MDL), based on 40 samples each at test concentrations of 5 and 10 ppbv, was found to be 1.9 and 2.0 ppbv, respectively. Performance of the CSSD was compared with the dinitrophenylhydrazine (DNPH) derivatization method for formaldehyde concentrations ranging from 5-50 ppbv, and a linear relationship with a coefficient of determination of 0.983 was found between these two analytical techniques. The CSSD was also used to monitor indoor formaldehyde concentrations in two manufactured homes. During this time, formaldehyde concentrations varied from below detection limit to 65 ppbv and were above the US National Institute for Occupational Safety and Health (NIOSH) recommended exposure limit (REL) of 16 ppbv, which is also the exposure limit value now adopted by the US Federal Emergency Management Agency (FEMA) to procure manufactured housing, 80% and 100% of the time, respectively.
尽管人们早就意识到长期接触甲醛会对健康产生不良影响，但这种有害空气污染物在室内环境中的测量仍是一项挑战。传统分析技术在住宅的单个位置评估数小时至数天内的甲醛浓度，这使得难以描述人类接触甲醛的每日时间和空间变化特征。需要一种便携式、易于使用的设备，该设备在短采样期内对气相甲醛具有特异性和敏感性，以便能更有效地研究室内环境中甲醛的归宿、迁移和潜在修复的动态过程。最近开发的一种设备将化学传感元件与分光光度分析相结合，用于检测和定量十亿分之一（ppbv）级的气相甲醛浓度。本研究确定了耦合传感器-分光光度设备（CSSD）在实验室环境中以30分钟采样周期准确连续报告低ppbv浓度甲醛的能力，此前该设备尚未在此低浓度下进行测试。基于40个测试浓度分别为5和10 ppbv的样品，确定的方法检测限（MDL）分别为1.9和2.0 ppbv。在甲醛浓度范围为5-50 ppbv时，将CSSD的性能与2,4-二硝基苯肼（DNPH）衍生化方法进行了比较，发现这两种分析技术之间存在线性关系，决定系数为0.983。CSSD还用于监测两栋装配式房屋内的室内甲醛浓度。在此期间，甲醛浓度从低于检测限变化到65 ppbv，分别有80%和100%的时间高于美国国家职业安全与健康研究所（NIOSH）推荐的暴露限值（REL）16 ppbv，该限值也是美国联邦紧急事务管理局（FEMA）在采购装配式房屋时采用的暴露限值。
