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Reversed-phase Column (reversed-phase + column)
Kinds of Reversed-phase Column Selected AbstractsSampling in the Great Lakes for pharmaceuticals, personal care products, and endocrine-disrupting substances using the passive polar organic chemical integrative samplerENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 4 2010Hongxia Li Abstract The passive polar organic chemical integrative sampler in the pharmaceutical configuration (i.e., pharmaceutical-POCIS) was calibrated for sampling at water temperatures of 5, 15 and 25°C to determine the influence of temperature on chemical-specific sampling rates (RS), thus providing more robust estimates of the time-weighted average concentrations of pharmaceuticals and personal care products (PPCPs) and endocrine-disrupting substances (EDS) in surface water. The effect of water temperature and flow on the RS of these analytes was evaluated in the laboratory with a static system. The loss of the test compounds from water by uptake into POCIS was linear over an 8-d period, and these experimental data yielded RS values in the range of 0.07 to 2.46 L/d across the temperature range for the 30 compounds tested. Water temperature and flow influenced POCIS uptake rates, but these effects were relatively small, which is consistent with the theory for uptake into POCIS samplers. Therefore, under a narrow range of water temperatures and flows, it may not be necessary to adjust the RS for POCIS. Except for acidic drugs and sulfonamide antibiotics, RS values were positively correlated with octanol,water partition coefficients (log KOW) of the test compounds. A linear relationship was also observed between RS and chromatographic retention times on a C18 reversed-phase column. These observations may provide a rapid method for estimating the RS of additional chemicals in the POCIS. The application of the RS to POCIS deployed for one month in Lake Ontario, Canada, during the summers of 2006 and 2008 yielded estimates of PPCP and EDS concentrations that are consistent with conventional concentration measurements of these compounds in Lake Ontario surface water. Environ. Toxicol. Chem. 2010;29:751,762. © 2009 SETAC [source] Quantitative peptidomics of mouse pituitary: comparison of different stable isotopic tagsJOURNAL OF MASS SPECTROMETRY (INCORP BIOLOGICAL MASS SPECTROMETRY), Issue 2 2005Fa-Yun Che Abstract Determining the relative levels of neuropeptides in two samples is important for many biological studies. An efficient, sensitive and accurate technique for relative quantitative analysis involves tagging the peptides in the two samples with isotopically distinct labels, pooling the samples and analyzing them using liquid chromatography/mass spectrometry (LC/MS). In this study, we compared two different sets of isotopic tags for analysis of endogenous mouse pituitary peptides: succinic anhydride with either four hydrogens or deuteriums and [3-(2,5-dioxopyrrolidin-1-yloxycarbonyl)propyl]trimethylammonium chloride with either nine hydrogens or deuteriums. These two labels react with amines and impart either a negative charge (succinyl) or a positive charge (4-trimethylammoniumbutyryl (TMAB)). Every endogenous mouse pituitary peptide labeled with the light TMAB reagent eluted from the C18 reversed-phase column at essentially the same time as the corresponding peptide labeled with the heavy reagent. Most of the peptides labeled with succinyl groups also showed co-elution of the heavy- and light-labeled forms on LC/MS. The mass difference between the heavy and light TMAB reagents (9 Da per label) was larger than that of the heavy and light succinyl labels (4 Da per label), and for some peptides the larger mass difference provided more accurate determination of the relative abundance of each form. Altogether, using both labels, 82 peptides were detected in Cpefat/fat mouse pituitary extracts. Of these, only 16 were detected with both labels, 41 were detected only with the TMAB label and 25 were detected only with the succinyl label. A number of these peptides were de novo sequenced using low-energy collisional tandem mass spectrometry. Whereas the succinyl group was stable to the collision-induced dissociation of the peptide, the TMAB-labeled peptides lost 59 Da per H9 TMAB group. Several peptides identified in this analysis represent previously undescribed post-translational processing products of known pituitary prohormones. In conclusion, both succinyl and TMAB isotopic labels are useful for quantitative peptidomics, and together these two labels provide more complete coverage of the endogenous peptides. Copyright © 2005 John Wiley & Sons, Ltd. [source] Identification of dimer impurities in ampicillin and amoxicillin by capillary LC and tandem mass spectrometryJOURNAL OF SEPARATION SCIENCE, JSS, Issue 3 2007Chi-Yu Lu Abstract A micro-scale liquid chromatography electrospray ionization tandem mass spectrometric method was developed for the identification of polymerized impurities in ampicillin and amoxicillin in aqueous solution. Ampicillin and amoxicillin are broad-spectrum antibiotics and widely used for the treatment of human and animal infections. In this study ampicillin, amoxicillin, and their dimers were trapped in a 5-cm capillary column containing C18 sorbents. The analytes were separated on a reversed-phase column and introduced into the mass spectrometer via a nanospray ion source. An isocratic mobile phase consisting of 1% formic acid-acetonitrile (50 : 50, v/v) was used. For identification, the fragment ions of the analytes were monitored. The aim of the present study was to develop an optimized quality control method for the analysis of high molecular weight impurities of ampicillin and amoxicillin. [source] Optimization of the separation conditions of tetracyclines on a preselected reversed-phase column with embedded urea groupJOURNAL OF SEPARATION SCIENCE, JSS, Issue 7 2006Leila Kallel Abstract The use of a C12 stationary phase with embedded polar group has been investigated for the separation of seven tetracyclines. The influence of pH, organic modifier, buffer, and temperature on the peak shape and analyte separation was discussed. It appears that all the chromatographic conditions had a great effect on both the resolution and peak shape whereas the elution order was not affected. The baseline separation with symmetrical peaks of the seven tetracyclines can be obtained with a mobile phase containing either 5 mM phosphate buffer pH 2.5/ACN (84 : 16 v/v) or 5 mM perchlorate buffer pH 2.5/ACN (75 : 25 v/v) at a temperature not exceeding 20°C. This study reveals that the retention mechanism is ion-pairing. [source] Analysis of secondary metabolites from eschscholtzia californica by high-performance liquid chromatographyPHYTOCHEMICAL ANALYSIS, Issue 4 2006Maya Klvana Abstract A rapid and precise analytical HPLC method has been developed for screening the major benzophenanthridine alkaloids produced by cell cultures of Eschscholtzia californica, namely, sanguinarine, chelirubine, macarpine, chelerythrine and chelilutine. Separation was achieved on a C18 reversed-phase column with gradient elution using acetonitrile and 50 mm phosphoric acid. Detection was performed by both fluorescence (,ex 330 nm, ,em 570 nm) and photodiode array, leading to good selectivity and precision in determining peak purity. A simple and quick sample preparation protocol was elaborated involving a methanolic extraction for the measurement of intracellular concentrations of the alkaloids and a solid phase extraction for their quantification in culture medium. Owing to the non-availability of commercially standards, a method for the purification of chelirubine, macarpine and chelilutine by semi-preparative HPLC was developed. Coupled together, the isolation method and the analytical method were highly reliable for screening the alkaloids of interest produced by E. californica. Copyright © 2006 John Wiley & Sons, Ltd. [source] Development of an efficient system for the separation of indole alkaloids by high performance liquid chromatography and its applicationsPHYTOCHEMICAL ANALYSIS, Issue 2 2001Irina Gerasimenko Abstract An efficient system for the analysis of indole alkaloids by HPLC on a reversed-phase column using an ion pair technique is described. The optimised chromatographic conditions allowed the successful separation of 22 standard monoterpenoid indole alkaloids (including some isomers) and tryptamine. The described HPLC system was applied to the analysis of alkaloids in intergeneric somatic hybrid cell cultures of Rauvolfia serpentina,×,Rhazya stricta. Copyright © 2001 John Wiley & Sons, Ltd. [source] Simultaneous quantification of CTN986 and its deglycosylation products in rat serum using liquid chromatography/tandem mass spectrometryRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 11 2006Jifen Guo A quantitative method for the simultaneous determination of CTN986, a flavonol triglycoside, and its two deglycosylation products rutin and hirsutin in rat serum was developed and validated for the investigation of the pharmacokinetics of CTN986. Analytes were isolated from the serum samples (200,µL) prior to analysis by liquid chromatography/tandem mass spectrometry (LC/MS/MS) using C18 solid-phase extraction, and were separated on a Zorbax C8 reversed-phase column with an isocratic mobile phase consisting of methanol/isopropanol/water/formic acid (20:10:70:0.1, v/v/v/v). The protonated analytes generated in the positive ion mode were monitored through multiple reaction monitoring in an eletrospray ionization source. Calibration was performed by internal standardization with CTN987, a flavonoid structurally similar to CTN986, and regression curves were constructed ranging from 2 to 1000,ng/mL in 200,µL serum samples. The intra- and inter-day precision values were below 11% and accuracy was between ,2.37 and 1.4% for all quality control samples. This quantitation method was successfully applied to pharmacokinetic studies of CTN986 in rats following oral and intravenous administration. Rutin and hirsutin were not detected in rat serum. Copyright © 2006 John Wiley & Sons, Ltd. [source] Determination of urinary S -phenylmercapturic acid, a specific metabolite of benzene, by liquid chromatography/single quadrupole mass spectrometryRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 9 2005Luciano Maestri A high-performance liquid chromatography/single quadrupole mass spectrometry (LC/MS) method is described for the determination of urinary S -phenylmercapturic acid (S-PMA), a specific metabolite of benzene. Urine samples were spiked with [13C6]S-PMA (used as the internal standard) and acidified; then they were purified by solid-phase extraction (SPE) on C18 cartridges. Analyses were conducted on a reversed-phase column by gradient runs with 1% aqueous acetic acid/methanol mixtures at different proportions as the mobile phase. The detector was used in electrospray negative ion mode (ESI,), the ions m/z 238 for S-PMA and 244 for [13C6]S-PMA being recorded simultaneously. The detection limit (for a signal-to-noise ratio,=,3) was 0.2,,g/L, thus allowing for the measurement of background excretion of S-PMA in the general population. The use of the internal standard allowed us to obtain good precision (CV% values <3%) and a linear calibration curve within the range of interest for monitoring occupational exposure to benzene (up to 500,,g/L). The method was applied to assay the metabolite concentration in a group of 299 workers (68 smokers and 231 non-smokers) occupationally exposed to relatively low levels of benzene (environmental concentration,=,0.4,220,,g/m3, mean 11.4,,g/m3) and 236 non-exposed subjects (134 smokers and 102 non-smokers). The results clearly showed that smoking must be taken into account for the correct interpretation of the results of S-PMA measurements for the assessment of work-related benzene exposure. When only non-smokers were selected, the mean excretion of S-PMA was significantly higher in workers exposed to benzene (1.2,±,0.9,,g/g creatinine) than in the control group (0.7,±,0.6,,g/g creatinine) (p,<,0.001), thus confirming the role of S-PMA as a biomarker of benzene on a group basis, even for relatively low exposure degrees. Copyright © 2005 John Wiley & Sons, Ltd. [source] Quantification of arecoline (areca nut alkaloid) in neonatal biological matrices by high-performance liquid chromatography/electrospray quadrupole mass spectrometryRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 17 2003Simona Pichini A high-performance liquid chromatography (HPLC) method with mass spectrometric detection is described for determination of arecoline in newborn meconium, urine and cord serum, using pilocarpine as internal standard. The analytes were extracted from neonatal biological matrices with chloroform/isopropanol (95:5, v/v) at alkaline pH. Extracts were analyzed by HPLC coupled to an electrospray (ESI) interface and a quadrupole mass spectrometer. Chromatography was performed on a C8 reversed-phase column using 10 mM ammonium acetate (pH 4.3)/acetonitrile (90:10, v/v) as mobile phase. The mass spectrometer was operated in selected ion monitoring mode. The method was validated over the concentration range 0.005,1.00,,g/g meconium, 0.004,1.00,,g/mL cord serum and 0.001,1.00,,g/mL urine. Mean recoveries ranged between 86.5 and 90.7% for arecoline in the different biological matrices, with precision always better than 10%. The quantification limits of arecoline were 0.005,,g/g meconium, 0.004,,g/mL cord serum, and 0.001,,g/mL urine. The method was applied to the analysis of neonatal biological matrices to assess eventual fetal exposition to arecoline. Two newborns from Asian mothers who declared areca nut consumption presented arecoline in meconium with concentrations in the range 0.006,0.008,,g/g; also the urine from one neonate tested positive for the drug. Copyright © 2003 John Wiley & Sons, Ltd. [source] Determination of perfluorooctane sulfonate in river water by liquid chromatography/atmospheric pressure photoionization mass spectrometry by automated on-line extraction using turbulent flow chromatographyRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 5 2003Masahiko Takino A simple, fast and sensitive liquid chromatography/atmospheric pressure photoionization mass spectrometry (LC/APPI-MS) method, with automated on-line extraction using turbulent flow chromatography (TFC), was developed for the determination of perfluorooctane sulfonate (PFOS) in river water. In this method, following an on-line extraction by injection onto a column under TFC conditions, PFOS is back-flushed onto a reversed-phase column via on-line column switching, and resolved chromatographically at a laminar flow rate of 1,mL min,1. Using this tandem LC-LC/APPI-MS system the extraction, separation and selective detection of PFOS in river water could be achieved with satisfactory selectivity and sensitivity. The limit of detection (LOD) (S/N,=,3) and the limit of quantitation (LOQ) (S/N,=,10)were 5.35 and 17.86,pg,mL,1. The described procedure was very simple since no off-line sample preparation was required, total analysis time being 18.75,min. Copyright © 2003 John Wiley & Sons, Ltd. [source] Synthesis of benzofurazan derivatization reagents for short chain carboxylic acids in liquid chromatography/electrospray ionization-tandem mass spectrometry (LC/ESI-MS/MS)BIOMEDICAL CHROMATOGRAPHY, Issue 4 2009Tomofumi Santa Abstract Benzofurazan derivatization reagents, 4-[2-(N,N -dimethylamino)ethylaminosulfonyl]-7-(2-aminopentylamino)-2,1,3-benzoxadiazole (DAABD-AP) and 4-[2-(N,N -dimethylamino) ethylaminosulfonyl]-7-(2-aminobutylamino)-2,1,3-benzoxadiazole (DAABD-AB), for short-chain carboxylic acids in liquid chromatography/electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS) were synthesized. These reagents reacted with short chain carboxylic acids in the presence of the condensation reagents at 60°C for 60 min. The generated derivatives were separated on the reversed-phase column and detected by ESI-MS/MS with the detection limits of 0.1,0.12 pmol on column. Upon collision-induced dissociation, a single and intense product ion at m/z 151 was observed. These results indicated that DAABD-AP and DAABD-AB are suitable as the derivatization reagents in LC/ESI-MS/MS analysis. Copyright © 2008 John Wiley & Sons, Ltd. [source] Determination of bergenin in human plasma after oral administration by HPLC-MS/MS method and its pharmacokinetic studyBIOMEDICAL CHROMATOGRAPHY, Issue 2 2009Jin Wang Abstract A highly sensitive, simple and selective high-performance liquid chromatography,tandem mass spectrometry (HPLC-MS/MS) method was developed and applied to the determination of bergenin concentration in human plasma. Bergenin and the internal standard (IS) thiamphenicol in plasma were extracted with ethyl acetate, separated on a C18 reversed-phase column, eluted with mobile phase of acetonitrile,water, ionized by negative ion pneumatically assisted electrospray and detected in the multi-reaction monitoring mode using precursor , product ions of m/z 327.1 , 192 for bergenin and 354 , 185.1 for the IS, respectively. The linear range of the calibration curve for bergenin was 0.25,60 ng mL,1, with the lowest limit of quantification of 0.25 ng mL,1, and the intra/inter-day relative standard deviation (RSD) was less than 10%. The method is suitable for the determination of low bergenin concentration in human plasma after therapeutic oral doses, and has been first and successfully used for its pharmacokinetic studies in healthy Chinese volunteers. Copyright © 2008 John Wiley & Sons, Ltd. [source] Determination of faropenem in human plasma and urine by liquid chromatography,tandem mass spectrometryBIOMEDICAL CHROMATOGRAPHY, Issue 1 2008Shouhong Gao Abstract A simple, rapid and sensitive liquid chromatography/electrospray tandem mass spectrometry (LC-MS/MS) quantitative detection method, using cefalexin as internal standard, was developed for the analysis of faropenem in human plasma and urine. After precipitation of the plasma proteins with acetonitrile, the analytes were separated on a C18 reversed-phase column with 0.1% formic acid,methanol (45:55, v/v) and detected by electrospray ionization mass spectrometry in positive multiple reaction monitoring mode. Calibration curves with good linearities (r = 0.9991 for plasma sample and r = 0.9993 for urine sample) were obtained in the range 5,4000 ng/mL for faropenem. The limit of detection was 5 ng/mL. Recoveries were around 90% for the extraction from human plasma, and good precision and accuracy were achieved. This method is feasible for the evaluation of pharmacokinetic profiles of faropenem in humans, and to our knowledge, it is the first time the pharmacokinetic of faropenem has been elucidated in vivo using LC-MS/MS. Copyright © 2007 John Wiley & Sons, Ltd. [source] A solid-phase extraction method for high-performance liquid chromatographic determination of salvianolic acid B in rabbit plasma: application to pharmacokinetic studyBIOMEDICAL CHROMATOGRAPHY, Issue 2 2007Yueming Ma Abstract A sensitive solid-phase extraction/high-performance liquid chromatographic method with ultraviolet detection was established for the analysis of salvianolic acid B in rabbit plasma. The analyte was separated on a reversed-phase column with trifluoroacetic acid,methanol,acetonitrile (70:10:20, v/v/v) as mobile phase at a flow rate of 1 mL/min, and ultraviolet detection at 315 nm. The calibration curve for salvianolic acid B was linear over the range 35,1400 µg/L with coefficients of correlation >0.999. The inter-day and intra-day precisions of analysis were <15%, and assay accuracy ranged from 95.3 to 109.1%. This method is suitable for determining salvianolic acid B in plasma and thus investigating the pharmacokinetics of salvianolic acid B. Copyright © 2007 John Wiley & Sons, Ltd. [source] Synthesis of benzofurazan derivatization reagents for carboxylic acids and its application to analysis of fatty acids in rat plasma by high-performance liquid chromatography,electrospray ionization mass spectrometryBIOMEDICAL CHROMATOGRAPHY, Issue 10 2005Yuhki Tsukamoto Abstract The derivatization regents for carboxylic acids, DAABD-AE {4-[2-(N,N -dimethylamino)ethylaminosulfonyl]7-(2-aminoethylamino)-2,1,3-benzoxadiazole}, MePZBD-AE {[4-(4- N -methyl)piperazinosulfonyl]-7-(2-aminoethylamino)-2,1,3-benzoxadiazole} and APZBD-NHMe {[4-(4- N -aminoethyl)piperazinosulfonyl]-7-methylamino-2,1,3-benzoxadiazole} were developed for electrospray ionization,mass spectrometry (ESI-MS). The derivatization reaction with fatty acids was completed at 60°C within 30 min. The derivatives of fatty acids were separated on a reversed-phase column and detected with ESI-MS. The detection limits attained for fatty acids were femtomol range and the calibration curves were linear over the range from 0.1 to 100 pmol (r2 > 0.992) for DAABD-AE and MePZBD-AE. DAABD-NHMe was applied to the analysis of fatty acids in rat plasma samples. Copyright © 2005 John Wiley & Sons, Ltd. [source] A new HPLC method for serum neopterin measurement and relationships with plasma thiols levels in healthy subjectsBIOMEDICAL CHROMATOGRAPHY, Issue 6 2004Ciriaco Carru Abstract Neopterin, a pyrazinopyrimidine compound, serves as a marker of cellular immune system activation, and it can be used as a prognostic predictor for certain types of diseases. We propose a new simple HPLC method to measure serum neopterin with highly sensitive ,uorimetric detection. After TCA serum protein precipitation, the supernatant was diluted ,ve times, injected into a C18 reversed-phase column and eluted at a ,ow rate of 1.5 mL/min by an isocratic water,acetonitrile (99:1) mobile phase. The natural ,uorescence of the molecule was detected at excitation wavelength 353 nm and emission 438 nm. In these conditions the neopterin retention time was about 4 min. Our proposed method was compared with a validated chromatographic separation, and the obtained data of the serum neopterin from 35 healthy volunteers were analysed by Passing,Bablok regression and Bland,Altman test. Neopterin measurement in healthy subjects was also employed to investigate on its potential relationships with plasma thiols levels. Copyright © 2004 John Wiley & Sons, Ltd. [source] Simultaneous determination of estramustine phosphate and its four metabolites in human plasma by liquid chromatography,ionspray mass spectrometryBIOMEDICAL CHROMATOGRAPHY, Issue 5 2004M. Breda Abstract A sensitive and selective method, using liquid chromatography,ionspray mass spectrometry, was developed and validated for the simultaneous determination of Estracyt (estramustine phosphate) and its four metabolites, estramustine, estromustine, estrone and estradiol, in human plasma. Deuterated internal standards were available for all analytes. The ,ve compounds were extracted from plasma by protein precipitation with acetonitrile. The chromatographic separation was performed using a Zorbax SB C18, (150 × 4.6 mm i.d., 5 µm) reversed-phase column under gradient conditions with a mobile phase containing 2 mm ammonium acetate buffer (pH 6.8) and acetonitrile. MS detection was by electrospray ionization with multiple reaction monitoring in the positive ion mode for estramustine phosphate, estromustine and estramustine, and in the negative ion mode for estrone and estradiol. The limit of quantitation was 10 ng/mL for estramustine phosphate, 3 ng/mL for estromustine, estramustine and estrone and 30 ng/mL for estradiol. Linearity was veri,ed from these LLOQs up to about 4000 ng/mL for the parent drug and 2000 ng/mL for the metabolites. Inter-day precision and accuracy values were all less than 15%. This assay was applied successfully to the routine analysis of human plasma samples collected in cancer patients administered estramustine phosphate intravenously. Copyright © 2003 John Wiley & Sons, Ltd. [source] Quantification of alkylresorcinols in human plasma by liquid chromatography/tandem mass spectrometryRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 5 2010Alastair B. Ross Alkylresorcinols (AR) are of interest as biomarkers of wholegrain wheat and rye intake in epidemiological studies and are currently mainly measured by gas chromatography/mass spectrometry (GC/MS) after labour-intensive sample preparation including liquid-liquid extraction, solid-phase extraction (SPE) and chemical derivatization. This manuscript describes and validates an alternative approach based on normal-phase liquid chromatography/tandem mass spectrometry for the quantification of alkylresorcinols in human plasma. The method requires neither SPE nor chemical derivatization and has a shortened run time compared to GC/MS. Normal- and reversed-phase columns and various mobile phases were evaluated with and without previous SPE of the samples. Normal-phase chromatography allowed separation of AR from the interfering triacylglycerols, diacylglycerols and sterols and enabled detection of AR even without SPE of the samples. The described method has instrumental lower limits of detection in the 25,75 pg range, and lower limits of quantification in the 75,250 pg range. Pooled human plasma and 2H4 -nonadecylresorcinol (internal standard) was applied to calibrate the method in the 20,12,000,nM range. The overall method showed intra-batch precision of 8.6% and an averaged accuracy of 100.2%. Applications for diverse human plasma samples are presented and are compared with the results determined by GC/MS. Based on the presented data; this method requiring less sample preparation is suggested for further evaluation as an alternative to GC/MS for analysis of biomarkers of wholegrain wheat and rye intake in epidemiological studies. Copyright © 2010 John Wiley & Sons, Ltd. [source] Enantioresolution of dl -penicillamineBIOMEDICAL CHROMATOGRAPHY, Issue 1 2010Ravi Bhushan Abstract Penicillamine (PenA) is a nonproteinogenic amino acid containing a thiol group. The three functional groups in penicillamine undergo characteristic chemical reactions and differ in their ability to participate in various chemical and biochemical reactions. d -penicillamine is more active pharmacologically, while the l -isomer occurs ,naturally'. This review deals with the enantioresolution of PenA both by direct and indirect methods using liquid chromatography. HPLC separation of its diastereomers prepared with different chiral derivatizing reagents (on reversed-phase columns) and separation of the derivatives prepared with achiral reagents (on chiral columns or via ligand exchange mode) has been discussed. Separation of enantiomers tagged with achiral reagent (to add a chromophore for ehanced detection) when there is no diastereomer formation has been considered separately. In addition, application of PenA and its derivatives as chiral selector for enentioresolution of certain other compounds has also been discussed. Copyright © 2009 John Wiley & Sons, Ltd. 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