Development of transparent film having functions of separation and sensing

基于水不相容第二相邻苯二甲酸二辛酯(DOP)增塑的聚氯乙烯(PVC)膜表面的离子对吸附，建立了一种新的、高灵敏、简便的测定痕量金属离子的方法。用2，2‘-二羟基偶氮苯(DHAB或H@&gt；D22@&gt；D2L)和结晶紫(CV^+)在ppb水平测定铝(III)和铁(III)。除了阳离子染料Cv^+的大摩尔吸光系数外，蓝紫色离子对物种Cv^+[M^&lt；III&gt；L_2]^-在反式母膜上的浓缩使测定变得简单而灵敏。在铝的情况下，黄色试剂(H_2L)、红色络合物([ALL_2]^-)和蓝紫阳离子(CV^+)三原色组合体系对铝的四个浓度范围(ppb-ppm)有明确的指示。微妙的颜色变化(卡其色-红棕色-蓝紫色-无色)可以很好地解释试剂、H_2L和铝的相对浓度。而在铁的情况下，由黄色(H_2L和[FeL_2]^-)和蓝色紫色(CV^+)组成的补色体系产生了不同的着色体系(黄色-橄榄绿-蓝紫色)。该体系已成功应用于水样中铝和人血清中铁的测定。由于这种方法基本上不受样品溶液中大分子和颗粒物的干扰，因此不需要分离血清蛋白质的准备程序。此外，将该方法应用于高效液相分析前的预富集步骤，能够在ppt水平上测定铝。

A new, highly sensitive and simple method for trace metal ions has been developed, based on the ion-pair adsorption on the surface of polyvinylchloride (PVC) film plasticized with dioctylphthalate (DOP), which serves as a water immiscible second phase. Aluminum(III) and iron(III) ions were determined at ppb level by the use of 2,2'-dihydroxyazobenzene (DHAB or H@>D22@>D2L) and crystal violet (CV^+). In addition to the large molar absorptivity of the cationic dye, CV^+, the enrichment of the blue violet ion-pair species, CV^+[M^<III>L_2]^-, onto the trancs-parent film has enabled the simple but highly sensitive determination. In the case of aluminum, the three primary colors combination system, yellow reagent (H_2L), red complex ([AlL_2]^-), and blue violet counter cation (CV^+), gave clear indication for four concentration ranges (ppb-- ppm) of aluminum. The delicate color changes (khaki-- reddish brown-- blue violet-- colorless) are well explained by the relative concentration of the reagent, H_2L, and aluminum. While, in the case of iron, the complementary color system consisting of yellow (H_2L and [FeL_2]^-) and blue violet (CV^+) brought about a different coloration system (yellow-- olive green-- blue violet). This system has been successively applied to the determination of aluminum in water samples and iron in human serum. No preparatory procedures for the separation of serum protein are required, since this method is essentially free from interferences from macromolecules and particulate matters in sample solutions. Further, the application of this method for the preconcentration step prior to HPLC analysis enabled the determination of aluminum at ppt level.