|
1. |
Fabrication of a Poly(Methylthiophene-methylpyrrole) Copolymer Br−Sensor and Its Application in Direct Potentiometry and Potentiometric Titration |
|
Analytical Letters,
Volume 30,
Issue 1,
1997,
Page 1-10
Zhi Wang,
Huanshen Zhang,
HarryB. Mark,
JuddithF. Rubinson,
Preview
|
PDF (274KB)
|
|
摘要:
Polymer-modified electrodes are one of the most rapidly growing areas of modern electrochemistry. These electrodes have aroused intense interest due to their inherent advantages such as simple and economic fabrication, fast and sensitive response, low resistance and high antifouling performance. A number of sensors have been developed for the direct potentiometric determination of ions in aqueous solution based on a correlation between a selective response and doping of the anion in the polymers. We report herein a new sensor modified with poly(methylthiophene-methylpyrrole) copolymer. This modified electrode shows near Nernstian response for Br−over a concentration range of 10−4to 10−1M. The electrode response also exhibits a sharp endpoint response for the potentiometric titration of Br−.
ISSN:0003-2719
DOI:10.1080/00032719708002285
出版商:Taylor & Francis Group
年代:1997
数据来源: Taylor
|
2. |
Flow-Injection Chemiluminescence Sensor for the Determination of Free Chlorine in Tap Water |
|
Analytical Letters,
Volume 30,
Issue 1,
1997,
Page 11-19
Wei Qin,
Zhujun Zhang,
Shuna Liu,
Preview
|
PDF (288KB)
|
|
摘要:
A novel chemiluminescence(CL) sensor combined with flow-injection analysis has been developed for determining free chlorine in tap water. The analytical reagent luminol was immobilized on an anion exchange resin column. While a volumn of sodium hydroxide passed through the column, luminol was eluted from the resin in alkaline aqueous solution and then mixed with a sample stream to react and produce CL. The CL emission intensity was correlated with the standard ClO−concentration in the range 1×10−8to 4×10−5g ml−1, and the detection limit was 8×10−9g ml−1ClO−. Interfering metal ions present in water were effectively separated by a pre-column cation exchanger. A complete analysis, including sampling and washing, could be performed in 1 min with a relative standard deviation of less than 5%. The sensor was stable for over 200 times and has been applied successfully to the determination of ClO−in tap water.
ISSN:0003-2719
DOI:10.1080/00032719708002286
出版商:Taylor & Francis Group
年代:1997
数据来源: Taylor
|
3. |
“Reagentless” Flow Analysis Determination of Hydrogen Peroxide by Electrocatalyzed Luminol Chemiluminescence |
|
Analytical Letters,
Volume 30,
Issue 1,
1997,
Page 21-31
JamesE. Atwater,
JamesR. Akse,
Jeffery DeHart,
RichardR. Wheeler,
Preview
|
PDF (385KB)
|
|
摘要:
Flow analysis methodology is presented for the determination of micromolar levels of aqueous hydrogen peroxide by luminol chemiluminescence. Adjustment of the pH to alkaline conditions and addition of the luminophore are implemented using in-line flow-through beds containing crystalline media. The requirement for a homogeneous catalyst is eliminated by electrochemical initiation of luminescence. Traditional laboratory reagents are replaced by packed beds containing solid phase basification media, and crystalline luminol. The methodology is suitable for application in both continuous flow and flow injection analysis configurations.
ISSN:0003-2719
DOI:10.1080/00032719708002287
出版商:Taylor & Francis Group
年代:1997
数据来源: Taylor
|
4. |
Calcium Optical Sensors Based on Lipophilic Anionic Dye and Calcium-Selective Organophosphate Ionophore or Neutral Carrier |
|
Analytical Letters,
Volume 30,
Issue 1,
1997,
Page 33-44
Enju Wang,
Leanne Ma,
Lin Zhu,
ChristopherM. Stivanello,
Preview
|
PDF (394KB)
|
|
摘要:
Lipophilic anionic dichlorofluorescein ester was examined as a chromophore for the development of polymeric film based optical sensors for calcium. A calcium organophosphate salt and a neutral ionophore were employed as the active component for calcium sensing. The response pH. dynamic range, detection limit and selectivities are governed by the calcium carrier as well as the membrane plasticizer. The membrane that uses the anionic chromophore and the calcium organophosphate salt responds to calcium in the range of 1.0 × 10−6to 0.2 M at pH 7.4.
ISSN:0003-2719
DOI:10.1080/00032719708002288
出版商:Taylor & Francis Group
年代:1997
数据来源: Taylor
|
5. |
A Glucose Selective Electrode Based on Calix[6]Arene and Application in a Human Serum Assay |
|
Analytical Letters,
Volume 30,
Issue 1,
1997,
Page 45-59
WingHong Chan,
YeeLing Wong-Leung,
TseFai Lai,
Ruo Yuan,
Preview
|
PDF (452KB)
|
|
摘要:
Plasticized poly(vinyl chloride) (PVC) membranes incorporating dealkylcalix[6]arene as a sensory material were developed for the determination of glucose after itsin situderivatization with a lipophilic Girard's P′ reagent. In a TRIS-HCl buffer at pH 9.0, the electrode exhibits a near Nernstian response in the range 1.0 × 10−4- 0.01 mol l−1glucose with a slope of 45.5 mV per concentration decade. The electrode has a fast response time and a long working lifetime. The selectivity and sensitivity of this electrode method allow its application to the assay of glucose concentration in human blood samples.
ISSN:0003-2719
DOI:10.1080/00032719708002289
出版商:Taylor & Francis Group
年代:1997
数据来源: Taylor
|
6. |
Enzymatic Spectrophotometric Determination of Glycerol-3-Phosphate and Glycerophosphorylcholine. |
|
Analytical Letters,
Volume 30,
Issue 1,
1997,
Page 61-68
M. Yaqoob,
A. Nabi,
I. Hafeez,
S.Atif Ali,
M. Masoom-Yasinzai,
Preview
|
PDF (239KB)
|
|
摘要:
A reliable enzymatic procedure has been devised for the determination of glycerol-3-phosphate and glycero-phosphorylcholine based on spectrophotometry. Glycerol-3-phosphate oxidase and phospholipase-D enzymes are used to produce hydrogen peroxide to oxidize iodide into triiodide at an elevated pH in the presence of Mo(VI), and the absorbance of the triiodide was read at 352 nm.
ISSN:0003-2719
DOI:10.1080/00032719708002290
出版商:Taylor & Francis Group
年代:1997
数据来源: Taylor
|
7. |
Extraction-Spectrophotometric Method for the Determination of Betamethasone in Pure Form and in Pharmaceutical Formulations |
|
Analytical Letters,
Volume 30,
Issue 1,
1997,
Page 69-78
A.S. Amin,
Y.M. Issa,
Preview
|
PDF (330KB)
|
|
摘要:
A sensitive and rapid extraction-spectrophotometric method for the determination of betamethasone, based on the formation of a charge transfer complex with benzocaprol red (I) and acid ethyl blue (II) is described. The calibration graph, resulting from the measurement of the absorbance of the chloroform and benzene extracts (10 ml) at 588 and 677 nm using I and II. respectively, is linear over the range 0–16 and 0–20 μg ml−1of betamethasone with relative standard deviations (R.S.D.) of 1.6 and 1.3% for 5 μg ml−1betamethasone using reagents I and II, respectively. For more accurate results. Ringbom optimum concentration ranges were found to be 2–14 and 2–17.5 μg ml−1using reagents 1 and II, respectively. The method was satisfactorily applied to the determination of betamethasone and its esters in pharmaceutical preparations and found in good agreement with the British Pharmacopeia (1993) method.
ISSN:0003-2719
DOI:10.1080/00032719708002291
出版商:Taylor & Francis Group
年代:1997
数据来源: Taylor
|
8. |
Determination of Doxycycline, Tetracycline and Oxytetracycline Simultaneously by Tlc-Fluorescence Scanning Densitometry |
|
Analytical Letters,
Volume 30,
Issue 1,
1997,
Page 79-90
Hong-zhi Xie,
Chuan Dong,
Yu-lin Fen,
Chang-song Liu,
Preview
|
PDF (345KB)
|
|
摘要:
A new sensitive, fast thin layer chromatography-fluorescence scanning densitometry(TLC-F) method is described for the simultaneous determination of doxycycline(DOTC), tetracycline(TC) and oxytetracycline(OTC). With a mobile phase chloroform: methanol:acetone: 1% aqueous ammonia(10:22:50:18, V/V) and a silica gel thin-layer, previously treated with 0.27 mol/L sodium EDTA solution adjusted to pH 9.0, all the tetracyclines were separated from each other. The Rf values are 0.52,0.35,0.21 for DOTC, TC and OTC, respectively. The fluorescent spots were scanned with a spectrodensitometer using 365nm as the excitation wavelength and the cut-off filter was set at 440nm. The linear ranges are 0.50∼25.6ng for DOTC; 0.96∼96.2ng for TC and 0.50∼49.6ng for OTC. The relative standard deviations(RSDs) are all <3.5%. The recoveries of them in honey, serum and urine are 94.5%∼107%.
ISSN:0003-2719
DOI:10.1080/00032719708002292
出版商:Taylor & Francis Group
年代:1997
数据来源: Taylor
|
9. |
Extractive-Spectrophotometric Determination of Furosemide with Sodium 1,2-Naphthoquinone-4-Sulphonate in Pharmaceutical Formulations. |
|
Analytical Letters,
Volume 30,
Issue 1,
1997,
Page 91-107
Adela Sevillano-Cabeza,
Pilar Campíns-Falcó,
M.Carmen Serrador-García,
Preview
|
PDF (527KB)
|
|
摘要:
An extractive-spectrophotometric study based on the reaction of furosemide with 1,2-naphthoquinone-4-sulphonate (NQS) is described. Optimal conditions are: NaH2PO4-Na2HPO4pH 7.5, NQS 7.7×10−3M, heating 30 min at 70° C and isoamyl alcohol as extractant. The method is used to determine furosemide in pharmaceutical samples. The interference caused by lactose can be eliminated using pH 4.5. The method can be also used to determine lactose at pHs 4.5 and 7.5.
ISSN:0003-2719
DOI:10.1080/00032719708002293
出版商:Taylor & Francis Group
年代:1997
数据来源: Taylor
|
10. |
Spectrophotometric Determination of Chlorpromazine |
|
Analytical Letters,
Volume 30,
Issue 1,
1997,
Page 109-119
Tehseen Aman,
A. Rashid,
I. Khokhar,
Javaid Iqbal,
Preview
|
PDF (308KB)
|
|
摘要:
Chlorpromazine hydrochloride reacts with cerium ammonium nitrate to give a pink colour having maximum absorbance at 530 nm. The reaction is selective for chlorpromazine, with 0.001 mg/ml as visual limit of quantitation, and provides a basis for a new spectrophotometric determination. The colour reaction obeys Beer's Law from 0.001 mg to 0.5 mg/ml of chlorpromazine. The standard deviation does not exceed 0.050. The method was successfully applied to pure and pharmaceutical dosage forms of chlorpromazine. The quantitative assessment of tolerable limits of other drugs was also studied.
ISSN:0003-2719
DOI:10.1080/00032719708002294
出版商:Taylor & Francis Group
年代:1997
数据来源: Taylor
|
|