使用30 cm试管的紫外可见分光光度计进行水分析

公共和私人供水设施每天测试和净化清洁饮用水和环境水源。然而，水净化过程会产生致癌的副产物，为了健康和水质的目的，必须对其进行识别和去除。虽然存在许多测试程序，但检测饮用水的方法是颜色分析，因为这可以指示作为致癌三卤甲烷前体的腐殖物质的浓度。饮用水测试方法中定义的最简单的颜色分析方法是使用颜色比较管进行目视检查。然而，这种方法的结果取决于观察者的感知，并不是真正的定量。本文介绍了一种用紫外-可见分光光度计和30cm波径长度样品池分析表面清洁水的新方法。扩展的样品室专门用于30厘米的圆柱形样品室，它提供了极低的吸光度值的精确测量，标准的10-100毫米样品池无法测量。通过在扩展的空间中放置一个积分球，可以获得所有的透射光并进行积分，以获得最大的吸收信号。Application NoteUV-0005 2/3Application NoteWater Analysis using a 30 cm Cell Water Analysis using a 30 cm Cell In t ro d uc t ion Public and private water faci li ties test and purify clean drinking and environmental water sources daily. However， water pu r ifica ti on processes can produce carcinogenic biproducts which must be identified a n d removed for health and water quality pu r poses.While numerous test i ng procedures exist ， the method for testing d ri nki n g water is a color analysis， since this can indicate the concentration of humic materials that are precursors to carcinoge n ic triha l omethane. The simplest method of color analysis defi n ed in test i ng methods for drink i ng water is a v i sual check with colo r comparison tubes. However ， res u lts of this method depend the observer's perception and are not tru l y qua n titative. V-670 UV-Visible Spectro p hotometer This application note in troduces a new method to analyze superficially clean water with a UV-Vis spectrophotometer and a 30 cm pathlength cell. The extended sample compa r t ment is dedicated for t he 30 cm cylindrical cell (F i gure 1)，wh i c h provides precise m easurements of samples with extreme l y low absorbance va l ues that ca n not be measured by the standard 10-100 m m cel l s. By placing a n integrating sphere in the extended compartment ， al l tr a n smi t ted light can be obtained and integ r ated to achieve the maximum absorpt i on signal. Figure 1. Exten d ed sa mp l e co mp a rt men t (l e f t) a nd 30 c m p at hlen g th c ell (r i g h t). K e yword s V-650/660/670，UV-Visi bl e /N IR ， Water Analysis， M a t e ri a l s， Qu a n titation ， Integrating s p here E xper i mental Measurement Conditions Measurement Range 850-220nm Data Pitch 0.5nm Slit Width L5nm Response Medium Scanning Speed 400 nm/min Re sults Each wa t er sampl e was measu r ed u si n g t h e 30 c m ce ll and subtra c ted using a base li ne air measureme n t . Th e u l t r a-p ure wate r p rovided t h e l owest a b sorbance th roug h out t he entire wav e lengt h range as seen i n Figure 2. Si n c e t h e u ltr a p ure wa t er i s cons i de r ed to b e al m ost clear ， the ul t r a -p ure wate r spect ru m was f u rt h e r em p loyed as a reference to cancel a ny reflection or absorptions of the sample cell . The cor r ected spectra for each sam p le are displayed as Fig u re 3. Figure 2. Abs o rpt ion sp e ctr a o f w at e r s ampl e s . Figure 3. Ab sor pt ion spe ct ra o f u lt rap ur e-cor rec te d water sa m p l es. The results obtained with th e 30 cm cell were a n alyzed with the [Color Diag n osis] program， and then plotted on the ch r oma ti city diagra m shown i n Fig u re 4. To demo n s t r at e th a t t h e color dif fe r e nc e s of the wate r samples cannot be clearly def in ed u sing t h e 10 mm cell ， addit i onal samples were measured with a 10 m m cell and t h e same calcu l at i on was performed and shown in Figure 5. JASCO INC. 28600 Mary's Cour t ， E a s to n ， M D 21601US A Figure 4. Chroma t i c i ty dia gr am o f w a t e r s a mpl e r esults u si ng t h e 30 c m c el l . Figure 5. C hr om a t icit y d ia gr am of wa t e r s a m p le r e sul t s u s i n g t h e 10 mm cel l . The chromaticity res u lts indicate th a t r i ver water is more yellow tha n the ot h er water sources a n d most p ro b a b ly co n tains humic materials. Con cl usion Using the JASCO 30 c m cell， the color of various wate r samples can be easily measured. This accessory is available for t h e measurement of extremely low concentration samples and for a wide variety of water ana l ysis fields . The extended sam p le compartme n t can be applied n ot only for liquid samples， but clear baculi f or m sol i d samples such as f i bers. 28600 Mary's Cour t ， E a s to n ， M D 21601US A