共查询到20条相似文献,搜索用时 31 毫秒
1.
p H值是溶液化学中重要的检测指标 .在工业、农业、生物、医学及环境保护等各个领域都有着广泛应用 .目前 ,多采用玻璃 p H电极进行 p H值的测量 .然而 ,玻璃 p H电极也存在一定的不足 ,玻璃敏感膜阻抗高达 1 0 10 Ω,容易造成电磁干扰 ;玻璃 p H电极极易破碎 ,难以适用于强搅拌的工业过程体系 ;氢氟酸能强烈地浸蚀玻璃膜 .因此 ,玻璃 p H电极不能长时间地用于含氟腐蚀体系 p H的测量 ;另外 ,玻璃 p H电极在强碱性溶液测量时会产生“钠差”.因此 ,多年来对非玻璃型 p H电极的研究一直是化学传感器研究领域中的活跃课题之一 .目前常见的… 相似文献
2.
《Electroanalysis》2006,18(15):1493-1498
Titanium nitride was used as pH‐sensitive material to fabricate all solid‐state pH electrode. The fabrication and the response performance of the pH electrode were described in the paper. The TiN film electrode showed a linear response in the pH range of 2–12 with a near‐Nenstian response (?55 mV/pH). The response time was within 1 min, and the electrode had good reproducibility, stability and low sensitivities for different species. Compared with the glass pH electrode, the electrode exhibited some advantages, for example, without activation, rapid response and high mechanical strength. In addition, the electrode performed excellently in a corrosion medium containing F?(1 M). Electrochemical behaviors of TiN electrode in Britton‐Robinson buffers were studied with Electrochemical Impedance Spectroscopy (EIS). 相似文献
3.
4.
Neel Sisodia Monica Miranda Kay L. McGuinness Jay D. Wadhawan Nathan S. Lawrence 《Electroanalysis》2021,33(3):559-562
This work presents the electrochemical response of a 2-(methylthio)phenol glassy carbon based electrode for a promising voltammetric pH sensor in both buffered and low-buffered solutions. Electropolymerization of the redox species was performed with the resulting polymer presenting a Nernstian response in buffered media, with a sensitivity of 51 mV/pH unit. The effectiveness of the sulfhydryl bond to facilitate proton transfer from the bulk solution to the phenol molecules has been confirmed, providing an accurate pH measurement of 8.28 in sea water media, compared to that measured with a calibrated glass pH probe of 8.30. 相似文献
5.
Demet Kuruo?lu Esin Canel Shahabuddin Memon Mustafa Yilmaz Esma Kili? 《Analytical sciences》2003,19(2):217-221
A hydrogen ion-selective poly(vinyl chloride) membrane electrode was constructed using 5,11,17,23-tetra-tert-butyl-25,26,27,28-tetracyanomethoxycalix[4]arene as a neutral carrier. The electrode showed an apparent Nernstian response in the 2-11.5 pH range with a slope of 54.0 +/- 0.2 mV/pH at 20 +/- degrees C. This electrode showed a rapid response of the emf to changes in the pH, high ion selectivity with respect to lithium, sodium and potassium, and characteristics similar to those reported for the conventional pH glass membrane electrode. It can be used as a potentiometric indicator electrode in hydrofluoric acid solutions. The effects of iodide, thiocyanate, perchlorate and bromide on the characteristics of the electrode were also considered. 相似文献
6.
A screen-printable method is proposed to prepare a ceramic carbon composite sensor for pH determination. The pH-sensing membrane of the sensor is prepared by sol-gel, graphite powder and zeolite, in which zeolite is used as a receptor of proton. The fabrication of this ceramic carbon sensor includes three steps: preparing electrode slides, making a pH-sensing composite ink and screen-printing the ink on electrode slides. Optimum conditions for the ceramic carbon composite film are established, and characters of the pH electrode (stability, reproducibility, lifetime and conductivity) are examined comparing with glass pH electrodes. The Nernst response to pH of the sensor is in the range of pH 1-12 with a slope of 60 mV per pH. The sensor has been applied to pH measurements of samples and satisfactory results were obtained with R.S.D. of 0.18-1.25%. 相似文献
7.
Guillaume Herlem Rabah Zeggari Sandrine Monney Yves Guillaume Tijani Gharbi 《Talanta》2010,82(1):417-421
The anodic oxidation of concentrated glycine based aqueous electrolyte on smooth platinum electrode leads to a strongly grafted polyglycine-like coating on the surface in an irreversible way. Due to the proton affinity towards amino groups of polyglycine (PG), the electrodeposited thin film was used as receptor for solid potentiometric pH sensor. In order to reach local pH measurement, we developed miniaturized microelectrodes on glass substrate thanks to photolithography process. We used silver chloride on silver as the reference electrode. The couple (silver chloride, PG based platinum electrode) of microelectrodes gives linear potentiometric response vs. pH in the range [2-12], reversibly and with a sensitivity of 52.4 mV/pH (for 1 mm electrode size). PG based pH electrode is compared to other organic polymer based pH receptor such as linear polyethylenimine (L-PEI), polyaniline (PANI) and glass membrane. 相似文献
8.
Teixeira MF Ramos LA Almeida Neves E Fatibello-Filho O 《Fresenius' Journal of Analytical Chemistry》2000,367(1):86-89
The construction and the application of a silica gel based carbon-epoxy indicator electrode for the potentiometric determination of acids and bases are described. The effect of composition of silica gel and carbon-epoxy, slope (mV/pH), linear response (pH range) and the use for acid-base titrations were investigated. The data obtained for the acid-base titrations were compared with those obtained using a glass electrode in the same conditions. The electrode showed a linear response in the pH 2 to 13 range with a slope of -40.5 +/- 0.4 mV/pH (at 25 degrees C) and a response time of less than 15 s. The lifetime of the electrode was higher than one year (over 6000 determinations) with a decrease of only 5% of the initial potentiometric response. The silica gel based carbon-epoxy electrode showed excellent results in the end-point indication potentiometric titrations in determination of acids and bases. The miniaturization of the proposed electrode for flow injection analysis was investigated. 相似文献
9.
W S Han M Y Park D H Cho T K Hong D H Lee J M Park K C Chung 《Analytical sciences》2001,17(6):727-732
A hydrogen ion-selective solid-contact electrode based on N,N,N',N'-tetrabenzylethanediamine has shown the best Nernstian slope and selectivity and the widest response range in a Tris buffered pH sample solution. Its linear dynamic range was pH 3.50-11.94, and the Nernstian slope showed 52.1 mV/pH (at 20 +/- 0.2 degrees C). When it was directly applied to human whole blood (in pH range 6.0-8.5) we could obtain the same satisfying results. This electrode continuously contacted a Tris 7.47 buffered solution, human whole blood and a hydrofluoric acid solution for one month without any loss of performance. Also, hydrofluoric acid did not influence the surface of this electrode, and thus it was maintained without showing any changes in potentials after being used in a hydrofluoric acid solution. The standard deviation in the determined e.m.f. differences was 1.5 mV (N = 5) for Tris buffer solutions of pH 6.5 and 1.1 mV at a Tris buffer solutions of pH 8.5. The 90% response time of the electrodes obtained by injecting of hydrochloric acid into the Tris buffer sample solution was less than 10 s. Especially, in the this paper, with these potential response characteristics of hydrogen ion selective poly(aniline) solid contact electrode, we have also presented the pH response mechanism of this electrode and the role of poly(aniline) and a doped anion in a poly(aniline) layer. 相似文献
10.
A procedure for estimation of measurement uncertainty of routine pH measurement (pH meter with two-point calibration, with
or without automatic temperature compensation, combination glass electrode) based on the ISO method is presented. It is based
on a mathematical model of pH measurement that involves nine input parameters. Altogether 14 components of uncertainty are
identified and quantified. No single uncertainty estimate can be ascribed to a pH measurement procedure: the uncertainty of
pH strongly depends on changes in experimental details and on the pH value itself. The uncertainty is the lowest near the
isopotential point and in the center of the calibration line and can increase by a factor of 2 (depending on the details of
the measurement procedure) when moving from around pH 7 to around pH 2 or 11. Therefore it is necessary to estimate the uncertainty
separately for each measurement. For routine pH measurement the uncertainty cannot be significantly reduced by using more
accurate standard solutions than ±0.02 pH units – the uncertainty improvement is small. A major problem in estimating the
uncertainty of pH is the residual junction potential, which is almost impossible to take rigorously into account in the framework
of a routine pH measurement.1
Received: 11 August 2001 Accepted: 22 February 2002 相似文献
11.
12.
The feasibility of a metal palladium electrode as the pH sensor in air-saturated aqueous solutions was evaluated. The measurement was based on an “on-site” precleaning step and a potential decay process. The experimental results showed a linear pH response with a sensitivity of around 60 mV/pH and good reproducibiliry. The temperature effect on the measurement was also evaluated. 相似文献
13.
Teixeira MF Ramos LA Fatibello-Filho O Cavalheiro ET 《Fresenius' Journal of Analytical Chemistry》2001,370(4):383-386
The construction and analytical evaluation of a PbO2-based graphite-epoxy electrode sensitive to H3O+, based on incorporation of lead(IV) oxide in a graphite-epoxy matrix, are described. The data obtained from a variety of acid-base titrations in aqueous and aqueous-ethanolic media were compared with those obtained by use of a glass electrode under the same conditions. The proposed electrode provides a linear response in the pH range from 1 to 11 with a slope of -58.7+/-0.3 mV pH(-1) and -60.8+/-0.2 mV pH(-1) in aqueous and ethanolic media, respectively. The response time was less than 15 s and the lifetime of the electrode was at least eight months (ca. 5000 determinations) and its performance is good in pH determination and end-point detection in potentiometric acid-base titrations in both aqueous and aqueous-ethanolic media. 相似文献
14.
《Analytical letters》2012,45(5):711-724
Abstract A flow injection potentiometric procedure is proposed for the determination of acidity of several samples using an antimony/ antimony oxide electrode. The ΔE/pH curve in phosphate buffer solutions in the pH range from 1.58 to 12.00 showed a linear sub-Nernstian behavior with an operational slope S =-42.1mV/pHc and a conditional standard potential of 264.8mV. This flow potentiometric electrode responds linearly to low acidity variations of dilute acetic acid solutions from 3.16 to 100mM with a slope of 30.1mV/dec and analytical frequency of 23 results/h. Good reproducibility and an average standard deviation of ±0.5% was obtained. The application of this sensor for the determination of coke acidity and acetic acid in vinegar is reported. 相似文献
15.
纳米Co3O4型固体pH电极的响应及应用 总被引:2,自引:0,他引:2
测定酸度目前广泛采用玻璃电极 .然而 ,由于玻璃电极是采用极薄的玻璃膜作为 H+的敏感膜 ,致使电极极易破碎 ,亦难以用于对玻璃有腐蚀作用的体系 ,如含氟体系 .此外它还具有体积大、成本较高、膜阻抗高而难以实现微型化、以及使用前需活化处理等缺点 .多年来对非玻璃型 p H电极的研究一直是个热门的研究课题 .其中以金属 /金属氧化物型固体 p H电极倍受关注 [1~ 6 ] .本文对氧化钴 (Co3 O4 )型固体 p H印刷电极的响应性能、选择性、重现性以及在含氟腐蚀体系 p H测定中的应用进行了研究 .Ф1 2型 p H计 (BECKMAN公司 ) ,2 3 2型饱和… 相似文献
16.
Bunthoon Laongsri Cheerapa Boonyakong Nongluck Tangpaisarnkul Chainarong Cherdchu 《Accreditation and quality assurance》2007,12(3-4):194-200
It has not been long that metrology is well accepted as an important part in analytical chemistry since it helps the chemists
to receive the best measurement and accurate results with traceability. The National Institute of Metrology Thailand (NIMT),
which is a public agency under the supervision of the Ministry of Science and Technology, not only focuses on physical standards
but also provides and maintains standards in chemical field. pH measurement is one of the most widely used in the laboratories
including industries and medical area in Thailand. The chemical laboratory starts working on the project with the objective
of disseminating an accurate result in routine pH measurement. In 2002, the laboratory provided a service in calibration of
pH meter and organized the first local interlaboratory comparison program (NIMT–C-ILC-1: pH buffer) in pH measurement. There
were three buffer solution samples in the range of acid, neutral, and base. A total of 44 laboratories participated in this
program. The NIMT chemical laboratory also participated in the proficiency testing program that was conducted by PSB Corporation
Testing Group in Singapore. In 2003, NIMT started research in preparation of secondary buffers by using highly accurate pH
meters with glass electrode systems. The laboratory produced three secondary buffers, which were pH 4.01, 6.86, and 9.18 with
uncertainty 0.020 pH at 25°C. The competence of the laboratory was shown by the measurement results of the pilot study (APMP.QM-P06),
which was organized by the APMP electrochemical analysis working group (EAWG/TCQM) in 2005. The title of this study was “pH
determination of two phosphate buffers by Harned cell method and glass electrode method”. NIMT aims to achieve for establishment
of the primary method for pH measurement in the near future.
Presented at -- “BERM-10” -- April 2006, Charleston, SC, USA 相似文献
17.
A glassy carbon electrode has been coated by electrodeposition with a thin film of cobalt based layered double hydroxide (LDH) and used as a pH sensor. The developed electrode displays a linear super‐Nernstian response (?76.2±0.6 mV/pH) in the pH range between 2 and 14 and it is particularly suitable to operate in strongly alkaline solution. The reproducibility of the sensor construction is good with a relative standard deviation of the calibration curve slopes of±2.5 % (n=4). The electrode has a response time comparable to that exhibited by commercial glass electrodes in the pH range examined and is not affected by interference from the most common anions and cations. 相似文献
18.
In this study, an ammonia-gas-sensing liquid-state membrane electrode based on 1-[(2-oxyphenyl)iminomethyl]-2-oxybenzene-O,O',N-ammin-nickel(II) (Ni(II)-Schiff base) as an ionophore was developed. This membrane electrode gave a very good performance and exhibited linear response with near-Nernstian slope of 50.7+/-0.5 mV per decade, within a concentration range of 1.0x10(-1)-1.0x10(-3) M. The electrode performance depends on the pH of the test solution and the optimum pH range was 10.0-11.5. The effect of concentration of internal solutions in the electrode was also investigated. The selectivity properties of the electrode towards aliphatic amines at a pH value of 10.2 were investigated with the mixed-solution method. Furthermore, the response time and lifetime of the electrode prepared were determined. 相似文献
19.
20.
本文研究了在玻碳电极上修饰不同物质所制得的pH传感器,通过电位滴定的方法比较得出先修饰聚苯胺,再修饰钴-氧化钴膜的电极对pH有较好的响应,能代替玻璃电极应用在实际样品测定中。探究了最佳修饰条件为:先在0.1mol/L苯胺的盐酸(1mol/L)溶液中, 电位范围为-0.2~1.0V,以100 mV/s 的扫描速度循环伏安扫描 10圈修饰聚苯胺膜;接着在含2.0×10-4 mol/LCo2+的PBS (pH=7.5)缓冲溶液中, 电位范围为-1.2~1.2V,以100 mV/s 的扫描速度循环伏安扫描 5圈修饰钴-氧化钴膜。得到的修饰电极响应斜率为-61.60 mV/pH,响应范围pH 0.5~13。 相似文献