16-6

ANALYTICAL SCIENCES, June 2000, VOL. 16, No.6
Copyright (C) 2000 The Japan Society for Analytical Chemistry

Reviews

Zwitterionic Ion-Exchangers in Liquid Chromatography

Pavel N. NESTERENKO* and Paul R. HADDAD**
*Department of Chemistry, M. V. Lomonosov Moscow State University, 119899, Moscow, Russian Federation
**School of Chemistry, University of Tasmania, GPO Box 252-75, Hobart 7001, Australia

A zwitterionic ion-exchangers represnt a new direction in the development of stationary phases for different modes of high-performance liquid chromatography. The combination of positively and negatively charged sites in a single particle, or within the functional groups of a single molecule attached the surface of an adsorbent, provides unique opportunities to vary the selectivity of the separation. The classification of zwitterionic ion-exchangers based on their structure, distribution of oppositely charged groups, and their applications is considered.

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Original Papers

Extraction-Spectrophotometric Determination of Trace Amounts of Barium by 18-Crown-6 and Rose Bengal

Hooshang PARHAM and Abbass G. FAZELI
Department of Chemistry, Faculty of Science, Azad University, Gachsaran, Iran

A simple and sensitive extraction-spectrophotometric method for the determination of barium is reported. The 18C6-barium-Rose Bengal (18C6-Ba-RB) ternary complex was quantitatively extracted into dichloromethane, and its absorbance was measured at 565 nm. The calibration graph is linear over a barium concentration range of 0.083 - 4.70 ug ml^-1. The limit of detection of barium was 17.7 ng ml^-1. The relative standard deviation (RSD) of ten replicate measurements was 2.19% for a 0.83 ug ml^-1 barium solution. The interference effects of various cations and anions were also studied and reported. The described method provides a simple and reliable means for determination of trace amounts of barium in real samples.

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Preparation and Characterization of Alkylphosphonate-Modified Magnesia-Zirconia Composite for Reversed-Phase Liquid Chromatography

Yu-Qi FENG,* Qing-He ZHANG,* Shi-Lu DA,* and Yan ZHANG**
*Department of Chemistry, Wuhan University, Wuhan, 430072, P. R. China
**Laboratory of MRAMP of China, Wuhan, 430072, P. R. China

A new material: magnesia-zirconia composite modified by an alkylphosphonate can be used as a reversed-phase stationary phase for high-performance liquid chromatography. The new material was characterized by elemental analysis, FTIR and ¹³C solid state NMR spectrometry. The pH stability of the new material was investigated using biphenyl and N,N-dimethylaniline as probes with methanol-water (60:40, v/v) as a mobile phase, after the column was continuously purged with solutions at extreme pH 2 and pH 11. The chromatographic performance of the new material was studied by using polycyclic aromatic hydrocarbons (PAHs) and basic compounds as probes. The results indicate that the new material is of high pH stability and can be used for separation of PAHs and basic compounds.

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Determination of Butyltin Compounds in Aqueous Samples by Gas Chromatography with Flame Photometric Detector and Headspace Solid-Phase Microextraction after in-situ Hydride Derivatization

G. B. JIANG and J. Y. LIU
Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P. O. Box 2871, Beijing, 100085, China

A method for the extraction and determination of butyltin species in aqueous samples by solid-phase microextraction (SPME) combined with a capillary gas chromatography-flame photometric detector (GC-FPD) is described. The butyltin species was converted to its hydride form by sodium tetrahydroborate (NaBH₄) in a closed headspace vial prior to extraction. A laboratory-assembled SPME device including a fused-silica fiber and a modified microsyringe protection part was used throughout the experiment. The extraction was an equilibrium process that depended on the butyltin species partitioning between the liquid phase and the fiber. When the equilibrium was reached, the fiber was directly transferred to a GC column under the protection of a microsyringe, where the analyte was thermally desorbed inside the heated injector and subsequently, separated in a HP-1 capillary column and detected by a laboratory-made flame photometric detector using quartz surface-induced tin emission. The detection limits based on the signal equal to 3 times of the base-line noise were 0.2 ug/L, 0.2 ug/L, 0.1 ug/L and 0.02 ug/L for monobutyltin (MBT), dibutyltin (DBT), tributyltin (TBT) and tetrabutyltin (TeBT), respectively. The recovery ranged from 85% to 117%. The proposed method has been applied to determination of butyltin species in various aqueous samples.

Rapid Determination of Benzene Metabolites Phenol and p-Cresol in the Urine of Petrol Station Workers by Gas Chromatography

GholamAli KHOSCHSORUR and Walter PETEK
University Surgical Clinic, Department of Clinical Chemistry and Laboratory Medicine, Graz, Austria

The determination of phenol and p-cresol in urine has been suggested as a suitable biomarker for the monitoring of benzene exposure of pump workers employed in petrol stations. A method for efficiently extracting a wide variety of drugs from urine for toxicological analysis by gas chromatography is presented. The sensitivity of the method is sufficient to monitor normal levels of phenol and p-cresol after exposure to benzene vapors. The detection limit of the method is low enough to measure urinary phenol and p-cresol at a concentration of 0.1 mg/l. The overall recoveries of urinary phenol and p-cresol relative to the internal standard, DPA, ranged between 95 and 96.5%. Our gas chromatographic method is a rapid, precise and economical one suitable to measure the metabolite benzene also in routine monitoring of phenol and p-cresol.

Computation Program System for Structural Analysis and Quantification of Organic Contaminants on Silicon Wafer Surfaces from Mass Spectra

Keiji SAITO,* Hiroshi SIMIZU,* and Toshio OGAWA**
*UBE Scientific Analysis Laboratory, Inc., Kogushi, Ube, Yamaguchi 755-8633, Japan
**Kanazawa Institute of Technology, Laboratory for Ecological Polymer and Organic Materials, Ohgigaoka, Nonoich, Ishikawa 921-8501, Japan

A computer program was developed for the identification and quantification of organic contaminants on silicon wafer surfaces and related materials based on GC/MS spectral data. Information, such as the retention time (RT), mass number and peak intensity, was stored on 359 chemical compounds in the database. Some empirical equations were presented for calculating the existence probabilities of certain organic compounds. This method was confirmed for the identification and quantification of ultratrace organic contaminants on silicon wafer surfaces and related materials.

Nondestructive Speciation of Solid Mixtures by Multivariate Calibration of X-Ray Absorption Near-Edge Structure Using Artificial Neural Networks and Partial Least-Squares

Akihito KUNO and Motoyuki MATSUO
Graduate School of Arts and Sciences, The University of Tokyo, Komaba, Meguro, Tokyo 153-8902, Japan

Two multivariate calibration methods, artificial neural networks (ANN) and partial least-squares (PLS), have been applied to the quantitative determination of iron species in solid mixtures by X-ray absorption near-edge structure (XANES). XANES spectra were successfully resolved by both methods, and the iron compounds in solid mixtures were quantified, even though the spectra of different compounds showed serious overlap. When iron compounds that were not contained in the model mixtures were subjected to the calibration model, ANN recognized the patterns of their XANES spectra as the nearest spectra of model compounds in shape, and gave more robust results than PLS. The self-absorption effect on the calculated values from XANES measured in the fluorescence mode was examined by comparing with transmission mode; it turned out that a spectral distortion by a self-absorption effect is irrelevant to the prediction performance of these multivariate calibration methods. The present study demonstrated that ANN and PLS are applicable to the chemical speciation of elements by XANES measured in the fluorescence mode.

A Novel Approach to the Retrieval of the Mass Spectrum of a Mixture

Feng GAN and Yi-zeng LIANG
College of Chemistry & Chemical Engineering, Institute of Chemometrics and Chemical Sensing Technology, Hunan University, Changsha 410082, P. R. China

A novel approach for a library search of the mass spectrum of a mixture is proposed, which is a hybrid of retrieval and calibration techniques developed in chemometrics. An index, called weighted reference existence index, has been developed to obtain a set of possible reference spectra corresponding to the spectrum of a mixture. A non-negative least-squares regression is then used to calculate the contributions of the components in the mixture. The real components and their relative quantities can be determined from the regression coefficients of a non-negative least-squares regression. Both simulated and real data are used to evaluate the proposed method, and the results are quite satisfactory.

Amperometric Biosensors for Sensing of Hydrogen Peroxide Based on Electron Transfer between Horseradish Peroxidase and Ferrocene as a Mediator

Yasuo NAKABAYASHI*^,** and Hajime YOSHIKAWA*
*Faculty of Engineering, Kansai University, 3-3-35 Yamate, Suita, Osaka 564-8680, Japan
**HRC, Kansai University, 3-3-35 Yamate, Suita, Osaka 564-8680, Japan

A non-conducting polymer film of 3-aminophenol, in which horseradish peroxidase was immobilized, has been prepared on a carbon paste electrode containing both ferrocene as a mediator and horseradish peroxidase by the electrochemical polymerization. The response currents of this hydrogen peroxide sensor linearly increased with increasing the concentration of hydrogen peroxide of 0.6 to 20 umol dm^-3; the straight line had a slope equal to 10.1 mA mol^-1 dm³ (r= 0.999). This hydrogen peroxide sensor may be available for the fabrication of other biosensors, e.g. glucose and cholesterol sensors, which are not influenced by easily oxidizable species, L-ascorbic acid and uric acid.

Bulk Acoustic Wave Sensing Technique Applied to Dibazol Assay in Serum and Urine

Yumei LONG, Weifeng LI, Deliang HE, Anhong ZHOU, Wanzhi WEI, Lihua NIE, and Shouzhuo YAO
College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China

A simple, rapid, specific and sensitive method for the assay of dibazol using a bulk acoustic wave technique is described. PVC film containing various activants was coated on one electrode of a piezoelectric quartz crystal to fabricate a dibazol bulk acoustic wave (BAW) sensor for the assay of dibazol. Neither a sample pretreatment nor separation was required. The logarithm of the frequency shift of the dibazol BAW sensor shows a linear relationship to the logarithm of the concentration of dibazol over the range 4.0x10^-8 - 9.0x10^-4 M with a detection limit of 4.0x10^-8 M. In this work, three kinds of ion-pair complexes, namely, dibazol with dicyclohexylnaphthalene sulfonate (DDCHNS), diisobutylnaphthalene sulfonate (DDBNS) and tetraphenylborate (DTPB), were synthesized and investigated. The influencing factors were also examined and optimized. A comparison of the BAW sensing technique with other methods for assaying dibazol was made.

Identification of Photolytical Transformation Products of Pentachlorophenol in Water

Jongki HONG,* Do-Gyun KIM,* Chaejoon CHEONG,* Seung-Yong JUNG,** Mi-Ran YOO,** Kang-Jin KIM,** Tae-Kwan KIM,*** and Yoon-Chang PARK***
*Korea Basic Science Institute, 52 Eoun-Dong, Yusung-Ku, Taejeon, Korea
**Department of Chemistry, Korea University, Seoul, Korea
***Department of Chemistry, Sungkyunkwan University, Suwon, Korea

The photodegradation of pentachlorophenol in water was examined with a high-pressure mercury lamp. A number of photodegradation products of pentachlorophenol, such as less-chlorinated phenols through reductive dechlorination, and catechol and trihydroxylated products via the addition of hydroxyl radicals, were observed as major products. Moreover, polychlorinated biphenylethers, hydroxylated polychlorobiphenylethers and polychlorinated dibenzo-p-dioxins as minor products were also formed by dimerization process during the photolysis of pentachlorophenol. These compounds were identified by gas chromatography-mass spectrometry. The degradation rate of PCP in water was measured against the UV-irradiation time. After the irradiation for 15 min, 75% of PCP was converted into a number of products through reductive dechlorination and oxidation. On the basis of the identified products, the photodegradation pathways of PCP under UV irradiation were proposed.

Analysis of Pressure Sensitive Adhesives by GC/MS and GC/AED with Temperature Programmable Pyrolyzer

Sadao NAKAMURA,* Masahiko TAKINO,* and Shigeki DAISHIMA**
*Kansai Branch Office, Yokogawa Analytical Systems Inc., 3-3-11 Niitaka, Yodogawa, Osaka 532-0033, Japan
**Yokogawa Analytical Systems Inc., 2-11-13 Nakacho, Musashino, Tokyo 180-0006, Japan

Gas chromatograph/mass spectrometer (GC/MS) and gas chromatograph/atomic emission detector (GC/AED) with temperature programmable pyrolyzer were used for analysis of pressure sensitive adhesives in adhesive tapes. Evolved gas analysis (EGA) profile of the adhesives was obtained by this temperature-programmed pyrolyzer directly coupled with MS via a deactivated metal capillary tube. The EGA profile suggested the optimal thermal desorption condition for additives and the subsequent optimal pyrolysis temperature for the remaining polymeric material. Rubbers were identified from pyrograms with the assistance of a new polymer library. The additives were selectively detected by monitoring hetero elements and these screening results of GC/AED enabled one to easily find additive peaks in complex chromatograms of GC/MS with interference of tackifier. The additives were able to be identified by the corresponding GC/MS data. Furthermore, the EGA profile gave significant data for crosslinking agents by using specific ion monitoring.

Kinetic Spectrophotometric Determination of Sulbutiamine in Pharmaceutical Preparations and in Human Serum

M. E.-S. METWALLY and Y. El-SHABRAWY
Department of Analytical Chemistry, Faculty of Pharmacy, University of Mansoura, El-Mansoura 35516, Egypt

A kinetic spectrophotometric method was developed for the determination of sulbutiamine based on the catalytic effect on the reaction between sodium azide and iodine in an aqueous solution. Sulbutiamine at concentrations of 0.5 to 20 ug/ml was determined by measuring the decrease in the absorbance of iodine at 348 nm by a fixed-time method. The decrease in the absorbance in the first 5 min from the initiation of the reaction is related to the concentration of the drug. The detection limit of the procedure was 0.2 ug/ml. The relative standard deviation for the replicate determination (n = 10) of 4 ug/ml was 1.05%. The proposed procedure was successfully utilized in the determination of the drug in pharmaceutical preparations and human serum.

Notes

New Extractive Spectrophotometric Determination of Flutamide in Pure and Pharmaceutical Formulations

Kanchugarakoppal S. RANGAPPA,* Padmarajaiah NAGARAJA,* and Kodagahalli Channaiah Srinivasa MURTHY**
*Department of Chemistry, University of Mysore, Manasagangotri, Mysore-570 006, India
**Department of Education in Science and Mathematics, Regional Institute of Education, Manasagangotri, Mysore-570 006, India

Solvent Extraction of Antimony(V) as Hexachloroantimonate(V) with Quaternary Ammonium Ions

Koichi YAMAMOTO and Takayuki SHIMAKAWA
Department of Materials Science, Yonago National College of Technology, 4448, Hikona, Yonago, Tottori 683-8502, Japan

¹⁹F and ²⁷Al NMR Study on the Formation of Al-EDTA-Fluoride Complex in Aqueous Solution

Takushi YOKOYAMA,* Tsutomu KURISAKI,** (the late) Setsuko KINOSHITA,** Shorin MATSUO,*** and Hisanobu WAKITA**
*Department of Chemistry, Faculty of Science, Kyushu University, Hakozaki, Higashi, Fukuoka 812-8581, Japan
**Department of Chemistry, Faculty of Science, Fukuoka University, Nanakuma, Jonan, Fukuoka 814-0180, Japan
***Biotech Resources Research Institute, Sikata, Sawara, Fukuoka 811-1103, Japan

Characterization of a Mixed-Anion Salt, BaCl(ClO₄), Isolated from Acetonitrile Solution

Masashi HOJO, Tadaharu UEDA, Masanori YAMASAKI, and Akihiko INOUE
Department of Chemistry, Faculty of Science, Kochi University, Akebono-cho, Kochi 780-8520, Japan

Correlation between the Relative Sensitivity Factors and the Sputtering Yields in Glow-Discharge Mass Spectrometry

Takashi SAKA* and Mika INOUE**
*Department of Applied Electronics, Daido Institute of Technology, 2-21 Daido-cho, Minami, Nagoya 457-8531, Japan
**Research and Development Lab., Daido Steel Co. Ltd., 2-30 Daido-cho, Minami, Nagoya 457-8545, Japan

Fast Separation of Oligonucleotide and Triplet Repeat DNA on a Microfabricated Capillary Electrophoresis Device

Masanori UEDA,*1^,*2 Yuriko KIBA,*1^,* 3 Hirohisa ABE,*4 Hiroki KUYAMA,*4 Akihiro ARAI,*5 Hiroaki NAKANISHI,*4 and Yoshinobu BABA*1^,*6
*1 Department of Medicinal Chemistry, Faculty of Pharmaceutical Sciences, The University of Tokushima, Tokushima 770-8505, Japan
*2 Japan Foundation for Aging and Health, Aichi 470-2101, Japan
*3 NEDO, Ministry of International Trade and Industry, Japan
*4 Technology Research Laboratory, Shimadzu Corporation, Kyoto 619-0237, Japan
*5 HPLC Business Department, Analytical Instruments Division, Shimadzu Corporation, Kyoto 604-8511, Japan
*6 CREST, Japan Science and Technology Corporation, Chiba 292-0812, Japan

Non-Acidic Matrix for the Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry of Acid-Labile Compounds

Yoshihito OHBA, Naomi KOTO, Kenji HAMASE, and Kiyoshi ZAITSU
Graduate School of Pharmaceutical Sciences, Kyushu University, Maidashi, Higashi, Fukuoka 812-8582, Japan

Instrumental Achievements

Crystal Structure of 1,2-Bis(4-allyl-2-methoxyphenoxy)-4,5-dicyanobenzene

Sema OZTURK,*1 Samil ISIK,*2 Mehmet AKKURT,*1 Erbil AGAR,*3 Selami SASMAZ,*3 and Hoong Kun FUN*4
*1 Department of Physics, Faculty of Arts and Sciences, Erciyes University, Kayseri-38039, Turkey
*2 Department of Physics, Faculty of Arts and Sciences, Ondokuz Mayis University, Kurupelit, 55139 Samsun, Turkey
*3 Department of Chemistry, Faculty of Arts and Sciences, Ondokuz Mayis University, Kurupelit, 55139 Samsun, Turkey
*4 X-ray Crystallography Unit, School of Physics, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia

Crystal Structure of N-(1,2,3,4-Tetrahydrocarbazole-1-yl)-2-methoxyacetamide

Tuncer HOKELEK* and Suleyman PATIR**
*Hacettepe University, Department of Physics, 06532 Beytepe-Ankara, Turkey
**Hacettepe University, Department of Science Faculty of Education, 06532 Beytepe-Ankara, Turkey

Crystal Structure of 3-Pentanone Semicarbazone

Mehmet AKKURT,* Sema OZTURK,* and Semra IDE**
*Department of Physics, Faculty of Arts and Sciences, Erciyes University, Kayseri-38039, Turkey
**Department of Physics Engineering, Hacettepe University, Beytepe, Ankara-06532, Turkey

Crystal Structure of 1-[2-[6-(4-Methoxyphenyl)-3(2H)-pyridazinone-2-yl]acetyl]-4-(2-pyridyl)piperazine

Sebnem Kandil INGEC,* Huseyin SOYLU,* Engin KENDI,** Deniz S. DOGRUER,*** and M. Fethi SAHIN***
*Gazi University, Gazi Education Faculty, Physics Department, 06500 Besevler, Ankara, Turkey
**Hacettepe University, Department of Engineering Physics, 06532, Beytepe, Ankara, Turkey
***Gazi University, Department of Pharmaceutical Chemistry, Faculty of Pharmacy, 06330, Hipodrum, Ankara, Turkey

Crystal Structure of 3-[2-(4-Pyridyl)]ethyl-6-(2,3-difluorobenzoyl)-2-benzoxazolinone

M. Murat CANDAN,* Engin KENDI,* Nesrin GOKHAN,** Hakki ERDOGAN,** and Mevlut ERTAN**
*Department of Engineering Physics, Hacettepe University, Beytepe 06532, Ankara, Turkey
**Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Hacettepe University, Slhhiye 06100, Ankara, Turkey