A molecularly imprinted solid phase extraction-differential pulsed elution (MISPE-DPE) method has been developed for the determination of nicotine in tobacco. Nicotine and a trace alkaloid myosmine were able to bind to the molecularly imprinted polymer (MIP) packed in a micro-column when acetonitrile was used as the mobile phase. However, over 95% of the bound myosmine could be desorbed and washed away by a 20 µl pulse of methanol, compared to only 43% of the bound nicotine. The remaining quantity of bound nicotine was desorbed by a 20 µl pulse of 1% trifluoroacetic acid in water, for direct UV detection at 254 nm. This MISPE-DPE method provided inherent selectivity for nicotine that allowed both a shorter analysis time (3 min) and a lower analysis cost than liquid chromatographic methods. A detection limit of 1.8 µg ml–1 and a linear dynamic range up to 1000 µg ml–1 were obtained. Preconcentration of 845 µl of a 10 ng ml–1 nicotine standard solution produced a detectable peak signal. These analytical figures of merit are superior to those reported previously for several nicotine–MIP-based methods.
建立了分子印迹固相萃取-差分脉冲洗脱(MISPE-DPE)测定烟草中尼古丁的方法。以乙腈为流动相时，尼古丁和微量生物碱肌胺能够与分子印迹聚合物(MIP)结合。然而，超过95%的结合肌氨酸可以被20µl的甲醇脉冲解吸和冲走，而只有43%的结合尼古丁。用1%三氟乙酸水溶液20µl脉冲解吸剩余的结合尼古丁，在254 nm处进行直接紫外检测。MISPE-DPE方法对尼古丁具有固有的选择性，与液相色谱方法相比，分析时间更短(3 min)，分析成本更低。检测限为1.8µg ml-1，线性动态范围达1000µg ml-1。预浓缩845µl 10 ng ml-1尼古丁标准溶液产生可检测的峰值信号。这些优点的分析数字优于先前报道的几种基于尼古丁- mip的方法。
{"title":"Determination of nicotine in tobacco by molecularly imprinted solid phase extraction with differential pulsed elution","authors":"W. Mullett, E. Lai, B. Sellergren","doi":"10.1039/A902509J","DOIUrl":"https://doi.org/10.1039/A902509J","url":null,"abstract":"A molecularly imprinted solid phase extraction-differential pulsed elution (MISPE-DPE) method has been developed for the determination of nicotine in tobacco. Nicotine and a trace alkaloid myosmine were able to bind to the molecularly imprinted polymer (MIP) packed in a micro-column when acetonitrile was used as the mobile phase. However, over 95% of the bound myosmine could be desorbed and washed away by a 20 µl pulse of methanol, compared to only 43% of the bound nicotine. The remaining quantity of bound nicotine was desorbed by a 20 µl pulse of 1% trifluoroacetic acid in water, for direct UV detection at 254 nm. This MISPE-DPE method provided inherent selectivity for nicotine that allowed both a shorter analysis time (3 min) and a lower analysis cost than liquid chromatographic methods. A detection limit of 1.8 µg ml–1 and a linear dynamic range up to 1000 µg ml–1 were obtained. Preconcentration of 845 µl of a 10 ng ml–1 nicotine standard solution produced a detectable peak signal. These analytical figures of merit are superior to those reported previously for several nicotine–MIP-based methods.","PeriodicalId":7814,"journal":{"name":"Analytical Communications","volume":"105 1","pages":"217-220"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80620423","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A method for measuring the release of lanthanum from some ceramic dental materials was required using air–acetylene atomic absorption spectrophotometry (AA-AAS), and an analytical procedure was devised based on the release of calcium in the presence of phosphate by lanthanum addition. The extent of phosphate interference in the determination of calcium by AA-AAS was assessed, and it was shown that the absorbance of a 10 ppm Ca standard was reduced by 45% in the presence of 20 ppm or more of phosphate (as PO4). Analysis of standards containing 10 ppm Ca, 20 ppm PO4, and lanthanum added at concentrations up to 100 ppm showed rapid increase of calcium absorbances from 10 to 40 ppm La, after which absorbance increased slowly to a constant value at 90 ppm La. This corresponded to the value of a 10 ppm Ca standard solution containing no phosphate. Closer examination of solutions containing 10–40 ppm La revealed a quantitative relationship between lanthanum levels and calcium absorbances which deviated slightly from Beer’s law. Consequent analysis of solutions containing various amounts of lanthanum in the presence of 10 ppm Ca and 20 ppm PO4 followed by repeated analysis of standards demonstrated good precision and reproducibility. The relative standard deviation for repeated standard analyses was 4.2%, and the detection limit was 0.6 ppm La representing an increase of sensitivity of approximately 100 times over lanthanum determinations using nitrous oxide–acetylene techniques. The method indicates that similar procedures may be used to estimate elements which exercise similar release effects.
{"title":"The estimation of lanthanum by air-acetylene atomic absorption spectrophotometry using an indirect procedure","authors":"S. J. Wilson, P. Marquis","doi":"10.1039/A900331B","DOIUrl":"https://doi.org/10.1039/A900331B","url":null,"abstract":"A method for measuring the release of lanthanum from some ceramic dental materials was required using air–acetylene atomic absorption spectrophotometry (AA-AAS), and an analytical procedure was devised based on the release of calcium in the presence of phosphate by lanthanum addition. The extent of phosphate interference in the determination of calcium by AA-AAS was assessed, and it was shown that the absorbance of a 10 ppm Ca standard was reduced by 45% in the presence of 20 ppm or more of phosphate (as PO4). Analysis of standards containing 10 ppm Ca, 20 ppm PO4, and lanthanum added at concentrations up to 100 ppm showed rapid increase of calcium absorbances from 10 to 40 ppm La, after which absorbance increased slowly to a constant value at 90 ppm La. This corresponded to the value of a 10 ppm Ca standard solution containing no phosphate. Closer examination of solutions containing 10–40 ppm La revealed a quantitative relationship between lanthanum levels and calcium absorbances which deviated slightly from Beer’s law. Consequent analysis of solutions containing various amounts of lanthanum in the presence of 10 ppm Ca and 20 ppm PO4 followed by repeated analysis of standards demonstrated good precision and reproducibility. The relative standard deviation for repeated standard analyses was 4.2%, and the detection limit was 0.6 ppm La representing an increase of sensitivity of approximately 100 times over lanthanum determinations using nitrous oxide–acetylene techniques. The method indicates that similar procedures may be used to estimate elements which exercise similar release effects.","PeriodicalId":7814,"journal":{"name":"Analytical Communications","volume":"163 1","pages":"31-33"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78068773","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Y. Ci, Chun-yang Zhang, Jun Feng, Ai-dong Lang, Chun‐hui Huang, Zhengfan Jiang
A new photoelectric method for analyzing cell-free apoptosis had been developed with ITO (a transparent electrode of indium–tin oxide coated borosilicate) technology. The C5710 mice liver nuclei responded with a negative photoelectric current pulse to white light (200–800nm). During the apoptosis of liver nuclei induced by dATP (deoxyadenosine-5-triphosphate), the photoelectric current showed a dynamic decrease, which was in accordance with the results of fluorescence microscopy and agarose gel electrophoresis. This photoelectric analytical method might provide a rapid and sensitive way to evaluate apoptosis quickly and in a continuous fashion.
{"title":"A photoelectric method for analyzing cell-free apoptosis induced by dATP","authors":"Y. Ci, Chun-yang Zhang, Jun Feng, Ai-dong Lang, Chun‐hui Huang, Zhengfan Jiang","doi":"10.1039/A900317G","DOIUrl":"https://doi.org/10.1039/A900317G","url":null,"abstract":"A new photoelectric method for analyzing cell-free apoptosis had been developed with ITO (a transparent electrode of indium–tin oxide coated borosilicate) technology. The C5710 mice liver nuclei responded with a negative photoelectric current pulse to white light (200–800nm). During the apoptosis of liver nuclei induced by dATP (deoxyadenosine-5-triphosphate), the photoelectric current showed a dynamic decrease, which was in accordance with the results of fluorescence microscopy and agarose gel electrophoresis. This photoelectric analytical method might provide a rapid and sensitive way to evaluate apoptosis quickly and in a continuous fashion.","PeriodicalId":7814,"journal":{"name":"Analytical Communications","volume":"48 1","pages":"143-145"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80384314","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
R. M. Seifar, R. J. Dijkstra, U. Brinkman, C. Gooijer
At-line coupling of surface-enhanced resonance Raman spectroscopy (SERRS) and reversed-phase ion-pair chromatography with an excitation wavelength of 514.5 nm was applied for the isocratic separation and identification of four representative basic dyes (basic fuchsin, nile blue, crystal violet and ethyl violet). The effluent from a chromatographic column was deposited on a thin layer chromatography (TLC) plate by means of a spray-jet interface and analysed by Raman spectroscopy. The presence of non-volatile ion-pair reagents (1-heptanesulfonic acid sodium salt, sodium perchlorate) did not interfere with the deposition process and also not with the SERRS experiments. In fact higher SERRS intensities were observed in the presence of the ion-pair reagents. Reliable spectra could be recorded down to 90 pg of dyes deposited on the TLC plate.
{"title":"At-line coupling of surface-enhanced resonance Raman spectroscopy and reversed-phase ion-pair chromatography","authors":"R. M. Seifar, R. J. Dijkstra, U. Brinkman, C. Gooijer","doi":"10.1039/A903254A","DOIUrl":"https://doi.org/10.1039/A903254A","url":null,"abstract":"At-line coupling of surface-enhanced resonance Raman spectroscopy (SERRS) and reversed-phase ion-pair chromatography with an excitation wavelength of 514.5 nm was applied for the isocratic separation and identification of four representative basic dyes (basic fuchsin, nile blue, crystal violet and ethyl violet). The effluent from a chromatographic column was deposited on a thin layer chromatography (TLC) plate by means of a spray-jet interface and analysed by Raman spectroscopy. The presence of non-volatile ion-pair reagents (1-heptanesulfonic acid sodium salt, sodium perchlorate) did not interfere with the deposition process and also not with the SERRS experiments. In fact higher SERRS intensities were observed in the presence of the ion-pair reagents. Reliable spectra could be recorded down to 90 pg of dyes deposited on the TLC plate.","PeriodicalId":7814,"journal":{"name":"Analytical Communications","volume":"89 1","pages":"273-276"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80386732","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
C. Casiot, V. Vacchina, H. Chassaigne, J. Szpunar, M. Potin-Gautier, R. Łobiński
An approach to the identification of unknown signals in selenium speciation analysis of yeast by reversed-phase chromatography with ICP-MS detection is described. The analytical strategy was based on: (i), heart-cutting of a Se-containing fraction in the reversed-phase chromatographic eluate followed by its lyophilization; (ii), pneumatically-assisted electrospray (ESI) MS and ESI tandem MS of the lyophilizate; and (iii) confirmation of the fragmentation pattern obtained using the sulfur analogue of the seleno compound that was expected to have been identified. The approach developed allowed the identification of Se–adenosylhomocysteine as the major selenium species in an extract of a selenized yeast sample.
{"title":"An approach to the identification of selenium species in yeast extracts using pneumatically-assisted electrospray tandem mass spectrometry","authors":"C. Casiot, V. Vacchina, H. Chassaigne, J. Szpunar, M. Potin-Gautier, R. Łobiński","doi":"10.1039/A900319C","DOIUrl":"https://doi.org/10.1039/A900319C","url":null,"abstract":"An approach to the identification of unknown signals in selenium speciation analysis of yeast by reversed-phase chromatography with ICP-MS detection is described. The analytical strategy was based on: (i), heart-cutting of a Se-containing fraction in the reversed-phase chromatographic eluate followed by its lyophilization; (ii), pneumatically-assisted electrospray (ESI) MS and ESI tandem MS of the lyophilizate; and (iii) confirmation of the fragmentation pattern obtained using the sulfur analogue of the seleno compound that was expected to have been identified. The approach developed allowed the identification of Se–adenosylhomocysteine as the major selenium species in an extract of a selenized yeast sample.","PeriodicalId":7814,"journal":{"name":"Analytical Communications","volume":"78 1","pages":"77-80"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84060520","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A very simple, rapid and highly sensitive fluorimetric method for the determination of enoxacin (ENX) is described. The method is based on the formation of Tb(III)–ENX complex in the aqueous solution, which fluoresces intensely with an emission maximum at 545 nm (Tb3+∶5D4 → 7F5) when excited at 335 nm. Optimum conditions for the determination were investigated. A linear relationship was obtained between the fluorescence intensity and ENX concentration in the range 8.0 × 10–9–6.0 × 10–6 M. The limit of detection was 5.9 × 10–10 M. Analytical recoveries from untreated urine samples spiked with ENX were in the range 95–102.5%.
{"title":"Study on fluorescence of the Tb(III)–enoxacin system and the determination of enoxacin","authors":"Y. Fangtian, J. Linpei, Z. Huichun","doi":"10.1039/A902452B","DOIUrl":"https://doi.org/10.1039/A902452B","url":null,"abstract":"A very simple, rapid and highly sensitive fluorimetric method for the determination of enoxacin (ENX) is described. The method is based on the formation of Tb(III)–ENX complex in the aqueous solution, which fluoresces intensely with an emission maximum at 545 nm (Tb3+∶5D4 → 7F5) when excited at 335 nm. Optimum conditions for the determination were investigated. A linear relationship was obtained between the fluorescence intensity and ENX concentration in the range 8.0 × 10–9–6.0 × 10–6 M. The limit of detection was 5.9 × 10–10 M. Analytical recoveries from untreated urine samples spiked with ENX were in the range 95–102.5%.","PeriodicalId":7814,"journal":{"name":"Analytical Communications","volume":"1 1","pages":"231-233"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90833644","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A gas chromatographic system has been developed for the direct analysis of atmospheric formaldehyde and other oxygenated hydrocarbons. This method utilises the trapping of analytes in a loop cooled with liquid nitrogen, separation by gas chromatography and then subsequent detection using a pulsed discharge helium ionisation detector (pdHID). The detection limit of this instrument is estimated to be 32 parts per trillion by volume (pptv) for 0.2 l of gas sampled at a flow rate of 30 ml min–1 (S/N at 4:1). A number of other compounds have been monitored simultaneously using this method, including higher molecular weight aldehydes and acetone. Continuous measurement of formaldehyde can be performed with a time resolution of 15 min, with longer analysis times required for inclusion of other species. Calibrations were performed using a permeation tube instrument for both formaldehyde and acetone. A linear response has been observed for formaldehyde sample volumes of 60–200 ml of a 272 ppbv sample (20–68 ng). For acetone a linear response was observed from 175–360 ml of a 30 ppbv standard (12–26 ng). A flame ionisation detector (FID) was also utilised during system development to confirm separation of formaldehyde from atmospheric hydrocarbons.
{"title":"Direct measurement of atmospheric formaldehyde using gas chromatography-pulsed discharge ionisation detection","authors":"M. Hunter, K. Bartle, P. Seakins, A. Lewis","doi":"10.1039/A809762C","DOIUrl":"https://doi.org/10.1039/A809762C","url":null,"abstract":"A gas chromatographic system has been developed for the direct analysis of atmospheric formaldehyde and other oxygenated hydrocarbons. This method utilises the trapping of analytes in a loop cooled with liquid nitrogen, separation by gas chromatography and then subsequent detection using a pulsed discharge helium ionisation detector (pdHID). The detection limit of this instrument is estimated to be 32 parts per trillion by volume (pptv) for 0.2 l of gas sampled at a flow rate of 30 ml min–1 (S/N at 4:1). A number of other compounds have been monitored simultaneously using this method, including higher molecular weight aldehydes and acetone. Continuous measurement of formaldehyde can be performed with a time resolution of 15 min, with longer analysis times required for inclusion of other species. Calibrations were performed using a permeation tube instrument for both formaldehyde and acetone. A linear response has been observed for formaldehyde sample volumes of 60–200 ml of a 272 ppbv sample (20–68 ng). For acetone a linear response was observed from 175–360 ml of a 30 ppbv standard (12–26 ng). A flame ionisation detector (FID) was also utilised during system development to confirm separation of formaldehyde from atmospheric hydrocarbons.","PeriodicalId":7814,"journal":{"name":"Analytical Communications","volume":"94 1","pages":"101-104"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86743579","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A new methodology, sandwich-type monitoring assay system using an estrogen response element (ERE)-immobilized piezoelectric biosensor in combination with flow injection technique, has been developed for analysis of estrogen (E). The principle of the assay is that the estrogen receptor (ER) captures estrogen and then the complex is bound with ERE immobilized on the sensor. It was confirmed that initial binding of the ERE with ER is significantly accelerated by the formation of an E–ER complex. This kinetic difference was monitored by real-time measurement of the resonance frequency of the ERE piezoelectric biosensor and applied to detect 17β-estradiol. The calibration graph was linear in the range 10–100 nmol l–1 with a detection limit of 7.8 nmol l–1, an RSD of 5.9% for 50 nmol l–1 (6 replicates), and one run time of 4 min. Gradient flow injection on-line connection to an array of ERE piezoelectric biosensors is in progress for the simultaneous determination of endogenous and synthetic estrogens in drinking water and urine. In comparison with present chromatographic methods coupled with MS, the proposed technique is simple, flexible and cheap and has great potential in applications such as field and on-site monitoring and screen testing of endocrine disruptors.
{"title":"A new sandwich-type assay of estrogen using piezoelectric biosensor immobilized with estrogen response element","authors":"Mo Zhihong, Long Xiaohui, F. Weiling","doi":"10.1039/A902872B","DOIUrl":"https://doi.org/10.1039/A902872B","url":null,"abstract":"A new methodology, sandwich-type monitoring assay system using an estrogen response element (ERE)-immobilized piezoelectric biosensor in combination with flow injection technique, has been developed for analysis of estrogen (E). The principle of the assay is that the estrogen receptor (ER) captures estrogen and then the complex is bound with ERE immobilized on the sensor. It was confirmed that initial binding of the ERE with ER is significantly accelerated by the formation of an E–ER complex. This kinetic difference was monitored by real-time measurement of the resonance frequency of the ERE piezoelectric biosensor and applied to detect 17β-estradiol. The calibration graph was linear in the range 10–100 nmol l–1 with a detection limit of 7.8 nmol l–1, an RSD of 5.9% for 50 nmol l–1 (6 replicates), and one run time of 4 min. Gradient flow injection on-line connection to an array of ERE piezoelectric biosensors is in progress for the simultaneous determination of endogenous and synthetic estrogens in drinking water and urine. In comparison with present chromatographic methods coupled with MS, the proposed technique is simple, flexible and cheap and has great potential in applications such as field and on-site monitoring and screen testing of endocrine disruptors.","PeriodicalId":7814,"journal":{"name":"Analytical Communications","volume":"2 1","pages":"281-283"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84101921","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A new method of depth profiling has been developed and applied to a Co-implanted Si-wafer. A square section of only some cm2 was chosen, a thin near-surface sublayer oxidized by an oxygen plasma and the oxidized sublayer precisely etched by a solution of hydrofluoric acid. The mass of Si within the sublayer was determined via differential weighing of the wafer piece and the mass of Co determined by TXRF (total reflection X-ray fluorescence) of the loaded acidic solution. These steps were repeated time and again in order to record a total depth profile showing the relative concentration of Co dependent on the depth within the wafer. The integration of this profile gave a total dose of 1.13 × 1017 ions cm–2 with high accuracy. The depth resolution of the new method might be in the order of a few nm, the detection limit about 0.01% or 5 × 1018 atoms cm–3 of Co.
{"title":"Depth profiling of a Co-implanted silicon wafer by total-reflection X-ray fluorescence analysis after repeated oxidation and HF-etching","authors":"R. Klockenkämper, A. Bohlen","doi":"10.1039/A809804B","DOIUrl":"https://doi.org/10.1039/A809804B","url":null,"abstract":"A new method of depth profiling has been developed and applied to a Co-implanted Si-wafer. A square section of only some cm2 was chosen, a thin near-surface sublayer oxidized by an oxygen plasma and the oxidized sublayer precisely etched by a solution of hydrofluoric acid. The mass of Si within the sublayer was determined via differential weighing of the wafer piece and the mass of Co determined by TXRF (total reflection X-ray fluorescence) of the loaded acidic solution. These steps were repeated time and again in order to record a total depth profile showing the relative concentration of Co dependent on the depth within the wafer. The integration of this profile gave a total dose of 1.13 × 1017 ions cm–2 with high accuracy. The depth resolution of the new method might be in the order of a few nm, the detection limit about 0.01% or 5 × 1018 atoms cm–3 of Co.","PeriodicalId":7814,"journal":{"name":"Analytical Communications","volume":"178 1","pages":"27-29"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80012153","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Using acrylamide as a hydrogen bonding functional monomer and (5R)-5-benzylhydantoin as a template, a molecularly imprinted polymer was prepared in a polar solvent, which exhibited good enantiomeric recognition properties. The binding selectivity of the polymer was evaluated by batch methods. Scatchard analyses showed that two classes of binding sites were produced in the imprinted polymer and their dissociation constants were estimated to be (4.6 ± 0.8) × 10–5 and (1.3 ± 0.2) × 10–4 mol L–1, respectively. This was in agreement with the prediction of the binding characteristics of the polymer by a spectrophotometric method. Study of the effect of water on the separation factor of the polymer further proved that the hydrogen bonding interactions played an important role in the recognition of acrylamide-based molecularly imprinted polymers.
{"title":"An acrylamide-based molecularly imprinted polymer for the efficient recognition of optical amino acid hydantoins","authors":"Jie Zhou, Xiwen He, Yijun Li","doi":"10.1039/A902025J","DOIUrl":"https://doi.org/10.1039/A902025J","url":null,"abstract":"Using acrylamide as a hydrogen bonding functional monomer and (5R)-5-benzylhydantoin as a template, a molecularly imprinted polymer was prepared in a polar solvent, which exhibited good enantiomeric recognition properties. The binding selectivity of the polymer was evaluated by batch methods. Scatchard analyses showed that two classes of binding sites were produced in the imprinted polymer and their dissociation constants were estimated to be (4.6 ± 0.8) × 10–5 and (1.3 ± 0.2) × 10–4 mol L–1, respectively. This was in agreement with the prediction of the binding characteristics of the polymer by a spectrophotometric method. Study of the effect of water on the separation factor of the polymer further proved that the hydrogen bonding interactions played an important role in the recognition of acrylamide-based molecularly imprinted polymers.","PeriodicalId":7814,"journal":{"name":"Analytical Communications","volume":"23 1","pages":"243-246"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73357786","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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