이온크로마토그래피를 이용한 토양 중 퍼클로레이트 정량에 관한 국제표준(안) 연구

Abstract

ABSTRACT Based on the literature study for the determination of perchlorate in soil we chose the ion chromatography as ameasurement method and decided to use 70 mM KOH as an eluent to avoid the interference derived from the co-elutionof pyrophosphate (P 2 O 74− ), tripolyphosphate (P 3 O 105− ). Also we proposed to use air dried soil through 0.15 mm sieve anddistilled water as an extractant. Under the these basic concepts, we carried out the experiments to set up the detailprocedure like solid to liquid ratio (S/L ratio), extraction time, device for extraction and indicating factors for qualitycontrol (e.g. precision, accuracy, MDL, LOQ). In case of time and device for extraction, 5 hours of mechanical shaking or1 hour of centrifugation showed better precision and accuracy than that of sonication for 1 hour According to these results,we proposed the extraction method combining 5 hours of mechanical shaking with 1 hour of centrifugation. From theaspect of S/L ratio, the ratio of 1/2 or 1/3 showed resonable precision and accuracy. In case of the ratio of 1/2, there wouldbe some problems in the separation process when the proportion of fine particle is high. Therefore, we proposed theextraction ratio of solid to liquid as 1/3 instead of 1/2. With the consideration of cost effectiveness and soil salinity, weproposed the use of cartridge for removing the interfering anions like chloride, sulfate and carbonate in specific samplesuch as saline soil.Key words : Perchlorate, Soil analysis, International standard, S/L ratio