| Cd（Ⅱ）enters the environment with industrial production such as mining,smelting,and electroplating,and selectively accumulates in different organs of the human body through the food chain,seriously harming human health.The conventional detection methods of Cd（Ⅱ）cannot take into account both time cost and detection performance.The detection method of optical sensing membrane based on polymer inclusion membrane（PIM）,makes the rapid detection of micro-trace ions possible,and has good application prospects in the field of analysis,because extraction and detection are carried out simultaneously,reducing time consumption,simplifying the operation steps.In this paper,the rapid detection of Cd（Ⅱ）by PIM-based optical sensing membrane and color test strips were discusses,and aims to provide theoretical support for the development and application of Cd（Ⅱ）portable detection devices.The main research contents are as follows:（1）PIM-based optical sensing membrane PAB-SM was prepared with trioctyl methyl ammonium chloride（Aliquat 336）as the extractant,polyvinyl chloride（PVC）as the matrix,and rhodamine B（Rh B）as chromogenic reagent.The effects of membrane composition,solution p H and response time on detection of Cd（Ⅱ）by PAB-SM were investigated,and the detection range and selectivity of Cd（Ⅱ）were evaluated.The results showed that when the content of Aliquat 336 was 41.86%,the effect of extraction and detection of Cd（Ⅱ）were the best.Under optimized conditions,PAB-SM can achieve rapid determination of Cd（Ⅱ）with a concentration between4.45×10-9～8.90×10-7mol/L,and the detection limit（LOD）reached 1.95×10-9mol/L.This method had good reproducibility and accuracy.However,Rh B had a certain water solubility,PAB-SM had strict time control requirements for the determination of Cd（Ⅱ）,and PAB-SM was not renewable.（2）PIM-based optical sensing membrane PDN-SM was prepared with PVC as the matrix,bis（2-ethylhexyl）phosphate（D2EHPA）whose mass fraction was 56.52%as the extractant,and 1-（2-pyridylazo）-2 naphthol（PAN）as chromogenic reagent.Combined with analytical methods such as ATR-FTIR and XRD,the chromogenic mechanism of PDN-SM and Cd（Ⅱ）was discussed.Under optimized conditions,PDN-SM achieved rapid determination of Cd（Ⅱ）with a concentration between 8.90×10-9～8.90×10-4mol/L within 15 minutes,and LOD reached 3.89×10-9mol/L.Compared with PAB-SM,the detection range of Cd（Ⅱ）has been expanded by three orders of magnitude.PDN-SM was used to determine the Cd（Ⅱ）content in the tap water sample,and the recovery rate of sample was within the range of 98～103%,which confirmed the good accuracy of this method.The monolayer adsorption mechanism of PAN on PD-PIM provided a kinetic basis for Cd（Ⅱ）detection.PAN is insoluble in water,ensuring the stability of detection performance of Cd（Ⅱ）by PDN-SM.（3）Under optimized detection conditions,PDN-SM achieved rapid detection of Zn（Ⅱ）and Cu（Ⅱ）of a concentration of 1.78×10-9～1.78×10-4mol/L,1.78×10-7～1.78×10-3mol/L,LOD was 3.42×10-10,1.23×10-7mol/L,respectively.Using o-phenanthroline,potassium iodide,hydroxylamine hydrochloride/potassium sodium tartrate as masking agents,PDN-SM can selectively determine the content of Cd（Ⅱ）,Zn（Ⅱ）and Cu（Ⅱ）in metal smelting wastewater.PDN-SM can be reused≥3 times.（4）Using PAN and dithizone（Dz）as the chromogenic reagent,the carrier materials,the concentration,ratio and soaking time of chromogenic reagent,Cd（Ⅱ）response time,the types and contents of surfactant and masking agents were optimized,standard colorimetric plates with strong anti-interference and obvious color scale were prepared,and semi-quantitative detection of Cd（Ⅱ）was achieved.The results showed that binary coloring type test paper was prepared by soking medium-speed qualitative filter paper on binary chromogenic reagent of 0.015%（w/v）PAN and 0.0075%（w/v）Dz at a ratio of 0.3/0.2 for 30 min,for detecting Cd（Ⅱ）with a concentration between8.90×10-7～8.90×10-4mol/L.The color development and inspection time were both 60s,which took short time and can be regarded as an ideal rapid detection method. |
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