共查询到19条相似文献,搜索用时 93 毫秒
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采用简单高效的分子印迹膜技术,制备了对羟基苯甲酸(PHA)分子印迹传感器。敏感膜采用循环伏安法(CV)在玻碳电极表面合成,采用CV、微分脉冲伏安法、线性扫描伏安法和电化学交流阻抗法在K3[Fe(CN)6]/K4[Fe(CN)6]溶液中测试此分子印迹传感器的性能。在最优条件下,PHA检测线性范围为0.6~8.0μmol/L,检测限(S/N=3)为0.2μmol/L。实验结果表明:该分子印迹传感器灵敏度高、选择性好并且具有良好的再生性能,传感器对与PHA结构相似的分子有较强的抗干扰能力,可望用于植物体分泌化感物质PHA的实时监测。 相似文献
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为了提高苯巴比妥分子印迹传感器的灵敏度,以甲基丙烯酸为功能单体,马来松香丙烯酸乙二醇酯为交联剂,热聚合了一种纳米氧化铜掺杂的苯巴比妥分子印迹传感器。分别采用循环伏安法( CV)、电化学交流阻抗法(EIS)、差分脉冲伏安法(DPV)、计时电流法(CA)对这种印迹传感器的电化学性能进行了研究。分别采用红外光谱、扫描电镜对此印迹传感器的结构及形貌进行了表征。结果表明,以铁氰化钾为分子探针的间接检测中,铁氰化钾的峰电流值与苯巴比妥的浓度在1.2×10-7~1.5×10-4 mol/L范围内呈现良好的线性关系(线性相关系数R=0.9984),检出限(S/N=3)为8.2×10-9 mol/L。将此印迹传感器用于实际应用,回收率在96.5%~103.0%之间。 相似文献
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水杨酸分子印迹膜电化学传感器的制备 总被引:3,自引:1,他引:2
以水杨酸为模板分子,采用循环伏安法电聚合形成聚吡咯膜,以固定电位过氧化法去除印迹分子,制备了水杨酸分子印迹膜电极.本印迹电极能促进水杨酸电氧化过程,有效地避免结构类似物(如苯甲酸)对其测定的干扰.循环伏安法用于电化学检测,当富集时间为10 min,磷酸盐缓冲溶液的pH=6.86 时,在1.0×10-6~2.0×10-3 mol/L浓度范围内,水杨酸氧化峰电流与其浓度呈良好的线性关系,检出限为0.8 μmol/L, 用分子印迹膜电极对加标样品进行分析,回收率为94.6%~103.4%. 相似文献
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采用多壁碳纳米管负载氢氧化铁纳米胶粒修饰的玻碳电极对三氯生进行固相微萃取富集,其萃取过程符合一级动力学方程和Temkin吸附等温方程。循环伏安法表明三氯生在0.558 V处有一不可逆的氧化峰,pH值与氧化峰电位呈良好的线性关系,表明三氯生的氧化过程为1个电子伴随着1个质子的反应。氧化峰电流随扫速增加而线性增加,为吸附控制反应,氧化峰电流与三氯生浓度的对数在3.333×10~(-6)~3.333×10~(-4)mol/L范围内呈线性关系,检出限达3.333×10~(-6)mol/L。该方法的重现性及选择性好,已用于洗手液中三氯生的检测。以MOPAC2012软件提供的PM7半经验分子轨道方法,在设计的三氯生与氢氧化铁纳米胶粒形成的络合物分子簇模型上进行半经验分子轨道计算,热力学及前线轨道相关系数的计算结果表明:形成的三氯生络合物的ΔG0,证明形成了稳定的三氯生络合物;且三氯生络合物形成过程中发生了电子转移。 相似文献
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基于石墨烯的毒死蜱分子印迹电化学传感器的制备及对毒死蜱的测定 总被引:3,自引:0,他引:3
利用分子印迹技术,以马来松香丙烯酸乙二醇酯为交联剂,使用自由基热聚合法在石墨烯修饰的玻碳电极表面合成毒死蜱( CPF)分子印迹聚合膜,制得了CPF分子印迹电化学传感器。采用循环伏安法、线性扫描伏安法和电化学交流阻抗法等,考察了此CPF分子印迹膜的电化学性能。在最佳检测条件下,传感器的峰电流与CPF浓度在2.0×10-7~1.0×10-5mol/L范围内呈线性关系,线性方程为Ip(μA)=-7.1834-0.2424C (μmol/L),相关系数r2=0.9959,检出限为6.7×10-8 mol/L(S/N=3)。构建了CPF分子印迹电化学传感器的动力学吸附模型,测得印迹传感器的印迹因子β=2.59,结合速率常数k=12.2324 s。传感器表现出良好的重现性和稳定性,并成功用于实际水样和蔬菜样品中CPF的测定,加标回收率为94.1%~101.4%。 相似文献
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《化学研究与应用》2015,(8)
以芦丁作为模板分子,邻氨基酚为功能单体,在金电极表面循环伏安法电聚合具有选择性识别芦丁的分子印迹膜。以Fe(CN)3-/4-作为探针分子,采用循环伏安法(CV)、差分脉冲伏安法(DPV)、交流阻抗法(EIS)研究了印迹膜的性能、分子印迹效应。优化了测定芦丁含量的条件,芦丁浓度在5.56×10-6~2.22×10-4mol·L-1范围内,其对数与峰电流呈线性关系,线性方程为:I(μA)=9.83 lgc(mol·L-1)+14.63,检出限为1.85×10-6mol·L-1,并比较了传感器对其结构相似化合物的选择性响应,发现传感器对芦丁检测具有良好的选择性。该传感器成功应用于黑茶中芦丁含量的测定。 相似文献
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A novel amperometric sensor based on electropolymerized molecularly imprinted polymer (MIP) for triclosan detection is reported. The sensor was prepared by electropolymerizing o-phenylenediamine (o-PD) on a glassy carbon electrode in the presence of template triclosan. The template can be quickly removed by NaOH solution. After incubating in acetate buffer for 15 min, the sensor response sensitively to triclosan over a linear range of 2.0 × 10− 7 to 3.0 × 10− 6 mol/L and a detection limit as low as 8.0 × 10− 8 mol/L is obtained. This sensor provides an efficient way for eliminating interferences from compounds with similar structures to that of triclosan. 相似文献
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《Electroanalysis》2018,30(2):320-327
A novel molecularly imprinted polymer (MIP) photoelectrochemical sensor was fabricated for the highly sensitive and selective detection of triclosan. The MIP photoelectrochemical sensor was fabricated using graphite‐like carbon nitride (g‐C3N4) and gold nanoparticles (AuNPs) as photoelectric materials. The MIP/g‐C3N4‐AuNPs sensor used photocurrent as the detection signal and was triggered by ultraviolet light (UV‐Light 365 nm). g‐C3N4‐AuNPs was immobilized on indium tin oxide electrodes to produce the photoelectrochemically responsive electrode of the MIP/g‐C3N4‐AuNPs sensor. A MIP layer of poly‐o‐phenylenediamine was electropolymerized on the g‐C3N4‐AuNPs‐modified electrode to act as the recognition element of the MIP/g‐C3N4‐AuNPs sensor and to enable the selective adsorption of triclosan to the sensor through specific binding. Under optimal experimental conditions, the designed MIP/g‐C3N4‐AuNPs sensor presented high sensitivity for triclosan with a linear range of 2×10−12 to 8×10−10 M and a limit of detection of 6.01×10−13 M. Moreover, the MIP/g‐C3N4‐AuNPs sensor showed excellent selectivity. The sensor had been successfully applied in the analysis of toothpaste samples. 相似文献
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A solid-phase microextraction (SPME) method for the determination of triclosan, methyl triclosan, 2,4-dichlorophenol and 2,3,4-trichlorophenol (considered as possible triclosan metabolites) in water samples was optimised. Analytes were first concentrated on a SPME fibre, directly exposed to the sample, and then triclosan and the two chlorinated phenols on-fibre silylated using N-methyl-N-(tert.-butyldimethylsilyl)-trifluoroacetamide (MTBSTFA). Methyl triclosan remained unaffected during the derivatization step. Compounds were determined using gas chromatography in combination with mass spectrometry (GC-MS). Influence of different factors on the efficiency of extraction and derivatization steps was systematically investigated. Using a polyacrylate (PA) fibre quantification limits below 10 ng/l, and acceptable relative standard deviations, were obtained for all compounds after an extraction time of 30 min. On-fibre silylation was carried out in only 10 min. Moreover, the efficiency of the procedure was scarcely affected by the type of water sample. The method was applied to several samples of treated and raw wastewater, triclosan was found in all samples, at concentrations from 120 to 14,000 ng/l, and 2,4-dichlorophenol in most of them, at levels up to 2222 ng/l. 相似文献
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三氯生是一种被广泛应用在家庭卫生用品中的抗菌消毒剂。虽然其本身不具有很强的毒性,但其在生物体内的代谢变化是否对生物和人体有害我们还不得而知。因此,研究三氯生在动物体内的代谢与动力学情况是具有重要意义的。本文采用超高效液相色谱串联三级四极杆质谱法来测定口服给药(5 mg/kg)后大鼠血浆中的三氯生的含量及其代谢产物。相对于多反应监测(MRM)技术,尽管其有较好的最低检测限,但选择离子监测(SIR, 又称为SIM)有更好的方法验证参数。在本试验中,选择离子监测方法检测限为10.8 ng/mL,方法的回收率、准确度、精密度和重现性都较高。用该方法测定的三氯生在大鼠体内的消除半衰期为(48.5±10.5) h。同时,还鉴定出其三氯生血浆中有分别被羟基化加磺酸化、葡萄糖醛酸化以及磺酸化的4个代谢产物。 相似文献
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The formation of 2,8-dichlorodibenzo-p-dioxin (2,8-DCDD) in the photolytic degradation of triclosan has evoked a great concern for its safety and environmental
fate. The photochemical behaviour of triclosan in daily-used chemical products, in which triclosan is present in relatively
high concentrations and coexists with surfactants, was, however, addressed less frequently. The present work is focused on
the mechanistic aspects of triclosan photodegradation in an aqueous medium with a relatively high concentration (≥ 30 mg L−1) and on the influence of pH (8.7 and 10.5) and surfactants (Triton X100, SDS, and CTMAB) on this process. The results demonstrated
that photodegradation was strongly affected by the pH and the presence of surfactants. Photodegradation products, including
2,4-dichlorophenol (2,4-DCP), 5-chloro-2-(4-chlorophenoxyl)-phenol, 2,8-DCDD, dimers, trimers, and other intermediates, were
identified. Based on the analysis of photoproducts, homolytic scission of ether bond, dechlorination, ring closure, and photo-polymerisation
were proposed as the main routes of triclosan photodegradation. 相似文献
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Canosa P Morales S Rodríguez I Rubí E Cela R Gómez M 《Analytical and bioanalytical chemistry》2005,383(7-8):1119-1126
The degradation of 2-(2,4-dichlorophenoxy)-5-chlorophenol (triclosan) in chlorinated water samples was investigated. Sensitive
determination of the parent compound and its transformation products was achieved by gas chromatography with mass spectrometry
detection after sample concentration, using a solid-phase extraction sorbent and silylation of the target compounds. Experiments
were accomplished using ultrapure water spiked with chlorine and triclosan concentrations in the low mg/l and ng/ml ranges
respectively. Chlorination of the phenolic ring and cleavage of the ether bond were identified as the main triclosan degradation
pathways. Both processes led to the production of two tetra- and a penta-chlorinated hydroxylated diphenyl ether, as well
as 2,4-dichlorophenol. The formation of 2,3,4-trichlorophenol was not detected in any experiment; however, significant amounts
of 2,4,6-trichlorophenol were noticed. All of these five compounds were also identified when triclosan was added to tap-water
samples with free chlorine concentrations below 1 mg/l. Minor amounts of three di-hydroxylated phenols, containing from one
to three atoms of chlorine in their structures, were also identified as unstable triclosan chlorination by-products. The analysis
of several raw wastewater samples showed the co-existence of important concentrations of triclosan and its most stable by-products
(2,4-dichlorophenol and 2,4,6-trichlorophenol), reinforcing the potential occurrence of the described transformations when
products containing triclosan are mixed with chlorinated tap water. 相似文献
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Farré M Asperger D Kantiani L González S Petrovic M Barceló D 《Analytical and bioanalytical chemistry》2008,390(8):1999-2007
In this work, the contributions of triclosan and its metabolite methyl triclosan to the overall acute toxicity of wastewater
were studied using Vibrio fischeri. The protocol used in this paper involved various steps. First, the aquatic toxicities of triclosan and methyl triclosan
were determined for standard substances, and the 50% effective concentrations (EC50) were determined for these compounds. Second, the toxic responses to different mixtures of triclosan, methyl triclosan, and
surfactants were studied in different water matrices, i.e., Milli-Q water, groundwater and wastewater, in order to evaluate
(i) the antagonistic or synergistic effects, and (ii) the influence of the water matrices. Finally, chemical analysis was
used in conjunction with the toxicity results in order to assess the aquatic toxicities of triclosan and its derivative in
wastewaters. In this study, the toxicities of 45 real samples corresponding to the influents and effluents from eight wastewater
treatment works (WWTW) were analyzed. Thirty-one samples were from a wastewater treatment plant (WWTP) equipped with two pilot-scale
membrane bioreactors (MBR), and the influent and the effluent samples after various treatments were characterized via different
chromatographic approaches, including solid-phase extraction (SPE), liquid chromatography coupled to tandem mass spectrometry
(LC–MS/MS), and SPE coupled to gas chromatography–mass spectrometry (GC–MS). The toxicity was determined by measuring the
bioluminescence inhibition of Vibrio fischeri. In order to complete the study and to extrapolate the results to different WWTPs, the toxicity to V. fischeri of samples from seven more plants was analyzed, as were their triclosan and methyl triclosan concentrations. Good agreement
was established between the overall toxicity values and concentrations of the biocides, indicating that triclosan is one of
the major toxic organic pollutants currently found in domestic wastewaters. 相似文献
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三氯生在光解时可能会产生二噁英类物质,因而它在日用化学品中的安全性受到学术界的广泛关注.本文采用高效液相色谱-电喷雾质谱研究了三氯生在紫外光照射下的光聚合反应,通过对产物的准分子离子分析,初步确定了7种光聚合产物.聚合物的分子离子分别为505、540、792,且有同分异构体存在,其异构体个数分别为2个、3个和2个.这些物质的产生主要由三氯生分子间脱除氯化氢、分子上脱除氯离子等过程来聚合完成.在光解溶液中也测到2,8-二氯代二苯并-对-二噁英,该物质则是通过分子自身脱除氯化氢而环化产生.同时应用液相色谱定性分析了不同光源对光聚物产生及含量变化的影响.结果表明,三氯生的光聚合反应受光源的影响显著,UVB比UVA更易产生聚合反应. 相似文献
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Huihui Lu Hongbing Ma Guanhong Tao 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2009,73(5):854-857
A spectrophotometric method for the determination of triclosan in personal care products was proposed. It was based on the reaction of sodium nitrite with p-sulfanilic acid in an acidic medium to form diazonium ion, with which triclosan further formed an azo compound in an alkaline medium. The resulting yellow colored product has a maximum absorption at 452 nm. A good linear relationship (r = 0.9999) was obtained in the range of 0–30 mg L−1 triclosan. A detection limit of 0.079 g L−1 was achieved and the relative standard deviation was 0.24% (n = 11) at 14 mg L−1 triclosan. The proposed method has been applied to the analyses of triclosan in several personal care products and the results were in good agreement with those obtained by high-performance liquid chromatography. 相似文献