摘要
苯二酚的三种异构体,由于其吸收光谱和荧光光谱均重叠严重,不能用常规分光光度法和荧光法进行同时测定.而以λ=0nm进行同步扫描时,在350～500nm之间具有相似的荧光光谱特征,其荧光强度有良好的加和性,可以对三者进行总量测定.研究还发现三种苯二酚异构体与Cu2+和异烟肼形成1∶1∶2的配位合物时,用△λ=30nm进行同步扫描并采用偏振和一阶导数法,间苯二酚的导数荧光峰位于260nm处,对苯二酚的导数荧光峰位于320nm处,两者能很好分开,而此时邻苯二酚荧光峰消失,因此可在三者的混合物中分别测定间、对苯二酚,然后再从总量中减去间、对苯二酚的含量,从而测到邻苯二酚的浓度,因此本工作通过上述方法可对三种苯二酚异构体进行同时测定.其线性范围均在3×10-6～5×10-4mol/L之内,间苯二酚和对苯二酚的检出限分别是2.5×10-7mol/L和3.1×10-7mol/L;其混和物总量的检出限是4.5×10-7mol/L,RSD均在5%以下.该方法简便快速,有良好的准确性和重复性,用于环境水样中三种苯二酚的同时测定,获得满意结果.
Three dihydroxybenzene （DHB） isomers could not be simultaneously determined by ordinary spectrophotometry and fluorometric method because the overlaps of their absorption spectra and fluores- cence spectra were severe. The total amount of these three isomers could be measured when they were synchronously scanned at △λ=0 nm because they have homoplastic character of fluorescence spectrum and favourable additivity of fluorescence intensity in 350~500 nm. It was found that when the three DHB isomers were bound with Cu^2＋ and isoniazide, ternary complexes were formed in a ratio of 1 ： 1 ： 2. When such complexes were synchronously scanned at △λ=30 nm using polarization and first order derivative techniques, the derivative fluorescence peak of m-DHB appeared at 260 nm, that of p-DHB appeared distinguishably at 320 nm, but that of o-DHB did not appear simultaneously at all. Thus the contents of m-DHB and p-DHB can be determined from their mixture respectively, and then the content of o-DHB can be obtained by subtraction of the contents of m-DHB and p-DHB from the total amount of the mixture. Hence these three DHB isomers can be simultaneously determined through the above method in the experiment. The system responds linearly to each of the three isomers concentrations in the range 3 × 10^-6~5 × 10^-4 mol/L with detection limit of 2.5 × 10^-7 mol/L for m-DHB, 3.6 × 10^-7 mol/L for p-DHB, the detection limit of the total amount of the mixture is 4.5 × 10^-7 mol/L, and the RSD of these systems was under 5%. The method is simple, convenient, quick, veracious and repeatable, which has been successfully applied to simultaneous determination of the three dihydroxybenzene isomers in water samples with satisfactory results.
出处
《化学学报》
SCIE
CAS
CSCD
北大核心
2007年第20期2309-2314,共6页
Acta Chimica Sinica
基金
国家自然科学基金(No.20475045)
重庆市教委科研(No.KJ051303)资助项目.
关键词
同步-偏振-导数荧光法
苯二酚异构体
异烟肼
Cu(Ⅱ)
同时测定
synchronous-polarization-derivative fluorescence spectrometry
dihydroxybenzene isomer
isoniazide
Cu（Ⅱ）
simultaneous determination
