Absorption of Iodide Ions in Aqueous Solution by ZIF-67 and ZIF-8

Two zeolite-like imidazate metal-framework materials ZIF-67 and ZIF-8 were synthesized by using Co(NO_(3))2,Zn(NO_(3))_(2),2-methyl imidazole and methanol as raw materials,and these two materials were used to adsorb iodine ions in water.The impact of pH,contact time and temperature etc.on the adsorption capability of iodide ions in aqueous solutions by the two ZIF materials was investigated.The results show that the optimal adsorption pH was 7,and the optimal adsorption time was 18 h.The adsorption of iodide ions by ZIF-67 was consistent with the Langmuir adsorption isotherm,while the absorption of iodide ions by ZIF-8 was in better consistency with the Freundlich adsorption isotherm.The maximum adsorption capacity of iodide ions by ZIF-67 and ZIF-8 was 141.81 and 474.02 mg/g respectively.The adsorption of iodide ions by the two materials was more in line with the quasi-first-order kinetic model,and the adsorption was monolayer adsorption.

Electrodeposited iodide ions imprinted polypyrrole@bismuth oxyiodide film for an electrochemically switched renewable extractor towards iodide ions

Effective extraction and regeneration of radioactive iodide is one of urgent concerns for the safe utilization of nuclear energy.As a novel environmentally benign ion separation technique,electrochemically switched ion extraction(ESIE)process can be applied for effective capture and recovery of iodide ions(I^(-)).Herein,a novel kelp seaweed-like core/shell I^(-)imprinted polypyrrole@bismuth oxyiodide(PPy/I^(-)@BiOI)composite film is successfully prepared for the selective I^(-)capture in the ESIE system.It is found that the I^(-)can be easily trapped in the PPy/I^(-)@BiOI film after I^(-)is in situ desorbed from the film by an electrochemical reduction process since it offers particular electroactive binding sites for I^(-)extraction.The I^(-)imprinted PPy/I^(-)@BiOI film displays an extraction capacity as high as 325.2 mg·g^(-1)for I^(-)with favorable stability.In particular,the extraction and desorption of I^(-)is achieved by adjusting the redox potential and the pristine PPy/I^(-)@BiOI film can be regenerated and reused for multiple times without decrease in extraction capacity.It is expected that such a PPy/I^(-)@BiOI film would be useful as an electrochemically switched renewable extractor that could capture and regenerate I^(-)from radioactive water.

The Effect of Mixed Iodide Salts on the Conductivity Behavior in Ag2O-V2O5-B2O3 Superionic Glass System

A superionic mixed metal iodide glass system [(PbI2 –CuI ) - Ag2O- V2O5- B2O3] has been prepared by splat quenching technique. The prepared glass samples are characterized by X-ray diffraction (XRD) and differential scanning calo- rimetry (DSC). The effect of mixed metal iodide salts concentration on electrical properties has been investigated by the complex impedance spectroscopy (CIS). AC conductivity analysis is carried out in the frequency range of 2MHz-1Hz at different temperatures and an enhancement in the conductivity with iodide salts is the main feature of the observed re- sults with an anomaly at 20 mole % of PbI2 –CuI.

NaCl型油田水中I^-的离子选择电极法测定

采用了NaCl溶液为离子强度调节剂(TISAB),离子选择电极法测定NaCl型油田水中I-离子的含量,并对该方法进行了测定条件实验的研究。标准曲线在7.94×10-6～1.00 mol/L范围内呈良好的线形关系,相关系数R2=0.999 5,平均回收率为98.9%,RSD(n=6)=1.0%,实验结果表明,该方法测定NaCl型油田水中的I-简便、快速、准确。

离子选择电极电位法研究S_2O_8^(2-)与I^-反应动力学

用离子选择电极电位法对S_2O_8^(2-)-Ⅰ^-体系反应动力学问题进行了探讨,研究了离子强度对反应速度的影响。结果表明:离子选择电极电位法可用于此体系的动力学研究,并且得到满意的结果;提出了该电极适用的浓度条件;得出生成CuI^+步骤为催化反应决定步骤的新结论;随着离子强度的增加dE/dt值增大,即反应速度加快。

Colorimetric and Photothermal Dual-modal Visual Detection of Iodide Ion Based on G-Quadruplex-Hemin Cascade Signal Amplification

The insufficient internal resorption of iodide ions(I−)leads to thyroid disorders,such as goiter,hypothyroidism,and cretinism in adults.In this paper,a portable point-of-care testing(POCT)platform was developed for the dual-modal analysis of I^(−),seamlessly integrating both colorimetric and photothermal thermometer techniques.The quantification of results was achieved using a standard thermometer or smartphone.G-Quadruplex/Hemin(G4/Hemin)is the DNAzyme with peroxidase-like activity.The catalytic efficacy of G-quadruplex structures can be enhanced with the help of I^(−),manifesting as multicolor transitions from colorless to green and then blue,and accompanied by the increase of temperature,which can be used for the quantitative detection of I^(−).Additionally,digital analysis according to the three-color channels(R/G/B)by a cellphone eliminated the requirement for intricate instruments.This dual-modal method for portable I^(−)determination is cost-effectiveness,simplicity,remarkable sensitivity(0.5 nmol/L)and selectivity.Besides,it was applied to determining the concentration of I^(−)in spiked serum samples.

FIA-IC法同时测定水中痕量I^-、SCN^-、ClO_4^-及草甘膦

采用活性碳纤维作吸附剂流动注射在线富集,并采用流动注射(FIA)―离子色谱(IC)联用技术对吸附柱中富集的I^-、SCN^-、ClO_4^-和草甘膦进行定量测定。结果表明,I^-、SCN^-、ClO_4^-和草甘膦的检出限为0.08~0.14mg/L,线性范围为0.01~5.00 mg/L,相关系数分别为0.997 9,0.999 0,0.998 7,0.998 1,加标回收率为94.9%~99.2%。

CdI₂Extraction with 18-Crown-6 Ether into Various Diluents: Classification of Extracted Cd(II) Complex Ions Based on the HSAB Principle

CdI2 in water was extracted with 18-crown-6 ether (L) into 10 diluents at 298 K. The following equilibrium constants were determined or evaluated: some extraction constants (Kex/mol-3·dm9 & Kex,ip/mol-2·dm6 for CdLI2, Kex±/mol-2·dm6 for CdLI+ with I-, & Kex2±/mol-1·dm3 for CdL2+ with 2I-), conditional distribution constants (KD,I for I-, KD,CdLI for CdLI+, & KD,CdL for CdL2+) between the two phases, and an ion-pair formation constant (K1,org/mol-1·dm3) for CdLI+ and that (K2,org/mol-1·dm3) for CdLI2 in the organic (org) phases. Using the K1,org and K2,org values, acidities of the complex ions, CdL2+ and CdLA+ (A- = I-, Br-, & Cl-), in the 11 diluents were classified by applying the HSAB rule. Especially, the CdLA+ ions were classified as the soft acids in 9 diluents. Also, molar volumes (Vj/cm3·mol-1) of j = CdLI2 and CdL2+ were determined with the regular-solution-theory plot of logKex,ip vs. logKD,L and its pseudo-plot of logKD,CdL, respectively. Here, KD,L denotes the distribution constant of L between the two phases. So, sizes among CdLA2 and CdL2+ were compared by using the Vj values. Additionally, some distribution equilibrium potentials (dep/V) between the water and org bulk phases were topically calculated from an equation of KD,I with KSD,I, where the symbol KSD,I shows a standard distribution constant of I- at dep = 0 V for a given diluent.

离子色谱-安培法检测地下水中的溴离子及碘离子

建立了在ICS5000+型离子色谱仪上同时测定地下水中溴离子与碘离子的方法,选择参数:AS19色谱柱,45 mmol/L NaOH淋洗液,进样量25μL,流速1.5 mL/min,电化学检测器,工作电极配置银电极,参比电极为氯化银电极,积分-安培检测法模式,波形选择器中施加的循环电位波形选择“Silver,Ag-AgCl RE,S^(2-),CN,I^(-),S_(2)O_(3)^(2-),Alkaline”。在此条件下测定有证标准物质GSB 07-1380-2001205406(水质溴化物)相对误差3.9%,GBW09113h(水中碘)相对误差5.8%。测定溴离子定量限6.0μg/L,碘离子定量限1.0μg/L;溴离子加标回收率为104.0%,碘离子加标回收率为95.0%;测定溴离子精密度3.0%,碘离子精密度2.1%;可以在10 min内完成检测。探讨了电化学检测器检测效果的影响因素,这些结论在实验中较实用却少见报道。建立的方法不受水样中其他主要阴离子(如氯离子)的干扰,方法选择性高;检出限可以达到μg/L级别,且分析时间短。该方法能满足地下水及其他环境水样品中溴和碘离子测定要求,弥补了现有标准方法的不足。

一种绿色合成的碘离子荧光探针的光谱研究

以2-萘硼酸为原料,电化学合成得到一种碘离子荧光探针(NPS),NMR和LC-MS确证了其化学结构.光谱测试结果表明,NPS能高选择性地识别I^(-),有较强的专一性,且识别过程不受其他阴离子的影响,有较强的抗干扰能力.同时,探针NPS对I^(-)具有较高的检测灵敏度,最低检出限为170.39 nmol/L.此外,该探针能够在酸性到弱碱性的范围内稳定地检测I^(-),应用范围广,可用于实际水样中I^(-)检测.综上所述,该探针的合成对未来I^(-)的识别和应用具有较强的参考价值.

Diatomite-KH560对水中碘离子吸附行为研究

研究γ-缩水甘油醚氧丙基三甲氧基硅烷(KH560)负载到廉价易得的硅藻土表面制备复合吸附剂Diatomite-KH560,探究其对水溶液中碘离子的高效吸附分离性能。通过浸渍水解实现硅藻土负载KH560,考察吸附时间、温度、pH、初始浓度和共存离子对Diatomite-KH560吸附碘离子的性能进行评价。结果表明,制备条件温和的Diatomite-KH560具有较高的热稳定性,KH560修饰量大于13.3%。Diatomite-KH560吸附碘离子达到平衡所需时间较长,这可能受控于碘离子在溶液中的扩散、在吸附剂表面的吸附反应速率等多因素的影响,随着吸附环境温度的升高,控速步骤转变为化学吸附过程;弱酸环境下,Diatomite-KH560上环氧基发生了质子化,形成了带正电荷的吸附位点,通过静电吸引作用吸附碘离子;根据卤水阴离子组成特征,考察了高浓度氯离子和微量溴离子和硫酸根对碘离子吸附的影响,发现初始Cl/I达到2500倍时,Diatomite-KH560对碘离子的吸附量仍有0.63 mg/g。根据EDS和FTIR表征结果,结合KH560分子结构式分析,Diatomite-KH560可能是通过环氧基质子化实现对碘离子的高选择性吸附。

Facile synthesis of gold nanoflowers as SERS substrates and their morphological transformation induced by iodide ions

We report a new strategy to prepare gold nanoflowers （AuNFs） using a two-step seed-mediated method. The as-prepared AuNFs were employed as surface-enhance Raman scattering （SERS） substrates, showing strong signal enhancement. We further found that iodide ions （I^-） could selectively induce the morphological transformation of AuNFs to spheres, resulting in a blue-shift of the localized surface plasmon resonance （LSPR） bands, a color change of the AuNFs solution from blue to red, and decreased SERS activity. This behavior allows the AuNFs to be used in the determination of I^-.

离子色谱法同时测定水中碘化物和草甘膦的研究

建立了一种同时测定水中碘化物和草甘膦的离子色谱方法,并对色谱条件进行了优化。采用瑞士万通A SUPP 5-150阴离子分析柱,以8 mmol/L碳酸钠为流动相,采用电导检测器实现了碘化物和草甘膦的同时分离和检测。在优化的色谱条件下碘化物检出限可达0.4μg/L,草甘膦检出限可达1.3μg/L,加标回收率为80.0%~120%。这一检测技术在水中碘化物和草甘膦中的应用操作流程少,步骤简单,同时具备较高的检测效率,分离作用优势明显,分析速度快,灵敏度高。

铋基材料去除水中碘离子的性能及机理

原生高碘地下水是造成我国多地居民碘摄入量过高并导致甲状腺疾病的主要因素之一,为探究水体除碘技术,采用溶剂热法合成两种铋基吸附剂即(BiO)_(x)(OH)_(1)(NO_(3))_(m)(CO_(3))_(n)(BIN)和(BiO)_(2)CO_(3),探讨这两种铋基材料在复杂水体环境(不同p H值、共存阴离子和模拟地下水)中对碘离子的去除性能及吸附稳定性,运用BET、SEM、XRD、FTIR、Raman、XPS等表征手段分析铋基材料的微观结构和吸附机理。结果表明:BIN和(BiO)_(2)CO_(3)除碘速率很快,通过与碘离子发生化学反应,形成BiOI来完成除碘,反应过程符合伪二级动力学模型,吸附率分别为93.81%和95.11%;Langmuir模型能更好地描述二者的吸附等温线,最大吸附容量分别为129.37 mg/g和113.76mg/g;当p H值介于3~7时,BIN和(BiO)_(2)CO_(3)对I^(-)的吸附效果良好,pH>9时,吸附率明显下降;共存阴离子和离子强度试验结果表明,NO_(3)^(-)对两种铋基材料吸附碘离子几乎没有影响,CO_(3)^(2-)对吸附影响较大,离子竞争性遵循CO_(3)^(2-)>SO_(4)^(2-)>Cl^(-)>NO_(3)^(-);在CO_(3)^(2-)/SO_(4)^(2-)/Cl^(-)含量为0~10mol/L条件下,I^(-)吸附率均随离子强度的增加而受到一定程度的抑制;吸附产物解吸试验结果表明,吸附产物在纯水中的解吸率都低于0.76%,4种阴离子(10mol/L)条件下的解吸率也都低于50%。这表明所制备的两种铋基材料对阴离子以SO_(4)^(2-)、NO_(3)^(-)和Cl^(-)为主的高碘水体具有较好的除碘效果和应用前景,对保障供水安全具有重要的实际意义。

g-CNQDs@Hg^(2+)开关型荧光探针的制备及其对水环境中碘离子的检测

以汞离子为桥梁,石墨相氮化碳量子点(graphitephase carbon nitridequantum dots,g-CNQDs)为发光体,成功设计了g-CNQDs@Hg^(2+)开关型荧光探针,并将其应用于水中I^(-)的识别和检测.使用硼酸-氯化钾-氢氧化钠溶液为缓冲液,pH值为7.4时,Hg^(2+)对g-CNQDs和I对g-CNQDs@Hg^(2+)荧光探针的最佳响应时间分别为180和60s.在最优实验条件下,g-CNQDs@Hg^(2+)的荧光强度与I^(-)的浓度在0.89~89μmol·L^(-1)范围内呈良好线性关系,I^(-)检出限为0.35μmol·L^(-1).研究结果表明,g-CNQDs@Hg^(2+)荧光探针对I^(-)具有较高的选择性和灵敏性,自来水和食盐中I^(-)的平均回收率分别为87.7%和84.26%,满足实际样品中I^(-)检测的分析要求.

离子色谱法测定地下水中碘离子的方法研究

采用离子色谱法测定地下水中碘离子。选择AS19分离柱、电导检测器、阴离子电解再生抑制器电流为99 mA、淋洗液为40 mmol/L KOH溶液、流速为1.00 mL/min、检测器温度为30℃、进样定量环为250μL。碘离子浓度在0.010 mg/L~1.00 mg/L的范围内与色谱峰面积具有良好的线性关系,其相关系数可以达到0.9998,方法检出限为0.001 mg/L,相对标准偏差为0.4%~8.3%,加标回收率为99.0%~115.0%,有证标准物质分析结果优秀,相对偏差为2.5%。将其应用于地下水中碘离子的测定,结果满意。

离子色谱法测定9V、11A、19A型肺炎球菌多糖中碘化钠残留量

建立检测9V、11A、19A型肺炎球菌多糖中碘化钠残留量的离子色谱方法,并进行验证。以Dionex IonPac AS11-HC阴离子交换层析柱为分析柱,Dionex IonPac AG11-HC阴离子交换柱为保护柱;采用低浓度氢氧化钠溶液为淋洗液等度洗脱,以电化学检测器进行检测。碘化钠的质量浓度在0.01~1.00μg/mL的范围具有良好的线性关系,决定系数R 2可达到0.9999,检出限为0.002μg/mL,定量限为0.010μg/mL。3个型别肺炎球菌多糖在低、中、高3个加标水平下的平均回收率为94.40%~103.91%,相对标准偏差(RSD)为0.17%~1.71%,均满足检测要求。方法无需复杂的样品前处理过程,测定快速,灵敏度高,结果准确,重复性好,可用于9V、11A、19A型肺炎球菌多糖中痕量碘化钠残留的检测。

离子色谱法测定地下水的碘化物

碘离子作为人体必要的摄入成分,在无外来碘摄入条件时,需以地下水中碘离子浓度含量的测定,判断当地人碘摄入量情况,确保其质量浓度不低于5μg/L。为此,本文以某地区水质测定为例,从检测方法选择、样品采集处理、试验条件设计和仪器试剂准备等方面进行离子色谱法测试方案的完善。其次,对碘化物测试工作开展峰面积定量、标准曲线分析和精密度测试等工作,离子色谱法的测定结果可靠,能实现准确、高效、自动化和无污染的地下水碘离子检测。

两种检测生活饮用水中碘化物的方法比对

电感耦合等离子体质谱(ICP-MS)法和离子色谱法以其灵敏度高,操作简单,试剂用量小等优点,在生活饮用水碘化物检测方法中占据优势地位。文章采用以上2种方法对饮用水中碘化物含量进行平行检测。试验表明,2种方法均具有较好的检测下限、较高的精密度、良好的加标回收率和稳定性。同时,2种方法又具备各自的特点,ICP-MS法线性范围更宽,样品消耗量更少,分析速度更快;但ICP-MS法检测碘化物时记忆效应明显,对仪器进样系统要求较高,且相较于离子色谱法应用成本更高。

水中碘化物的3种测定方法比较

目的:通过离子色谱法、硫酸铈催化分光光度法、电感耦合等离子体质谱法3种方法测定水中碘化物,通过实验比较,分析3种方法的优缺点。方法:选取质控样品作为实验对象,按照3种方法实验步骤测定各实验组水中碘化物浓度。结果:3种检测方法线性关系均满足实际检测要求,且相关系数R^(2)≥0.999。电感耦合等离子体质谱法检出限为0.6μg·L^(-1),加标回收率为100.8%,相对标准偏差为0.36%~0.45%;硫酸铈催化分光光度法检出限为1.2μg·L^(-1),加标回收率为84.4%,相对标准偏差为0.80%~1.91%;离子色谱法检出限为8μg·L^(-1),加标回收率为91.4%,相对标准偏差为0.23%~1.11%。结论:3种检测方法检测范围广、灵敏度高,且精密度和准确度表现良好,均可准确测定水中碘化物的含量。