测定乙二醇紫外透光率的影响因素

Impact Factors on the Determination of Ethylene-Glycol Ultraviolet Transmittance

本文对测定乙二醇紫外透光率(UV值)所涉及的影响因素(如,参比用水质、溶解氧、波长准确度等)进行了考察。实验结果表明:参比水的水质是测定乙二醇的UV值的关键,需采用二级水以上的参比水进行测定;试样中的溶解氧对220 nm处透光率测定结果影响很大,试样的放置时间在一天以内的,应以不低于50 m L/min的氮气流速吹脱试样15 min。对放置时间较长的试样,应以160 m L/min的氮气流速吹扫试样15 min;波长准确度是测定220 nm处UV值的前提,建议在仪器年检合格的情况下定期用萘-异辛烷溶液进行校准。

In this paper, the determination of ethylene glycol transmittance of ultraviolet (UV) involved in the influence factors (such as reference in water,dissolved oxygen, wavelength accuracy, etc.) was investigated. The experimental results show that the reference of water quality is the key to the determination ofethylene glycol UV value, need to use the reference of the secondary above water were determined; dissolved oxygen in a sample of 220 mm light transmittance whick has great influence on the determination results, the placement of sample time within aday, shall be not less than 50 mL/min to remove nitrogen flow sample 15 min. To place sample for a longer time, should be purging in a 160 mL/min nitrogen flow sample 15 min. Accuracy of wavelength was measured at 220 nm UV value,suggested that under the condition of the instrument inspection qualified calibration with naphthalene-isooctane solution on a regular basis.