Selective comprehensive multidimensional separation for resolution enhancement in high performance liquid chromatography. Part II: Applications

Groskreutz, Stephen R.; Swenson, Michael M.; Secor, Laura B.; Stoll, Dwight R.

doi:10.1016/j.chroma.2011.06.038

Cited by 41 publications

(21 citation statements)

References 23 publications

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“…While off-line LC×LC 24, 25 is clearly the best way to generate very high peak capacities (but it is very expensive in terms of analysis time), on-line LC×LC is surely the best way to generate large peak capacities in a relatively short analysis time 22 (15–30 min). In both on-line and off-line modes many restrictions apply such as compatibility of mobile phases between both dimensions 26, 27 , limits on volume of sample injected in the second dimension 28 and the strength of the sampled solvent from the first dimension 29, 30 .…”

Section: Resultsmentioning

confidence: 99%

Improving Peak Capacity in Fast Online Comprehensive Two-Dimensional Liquid Chromatography with Post-First-Dimension Flow Splitting

et al. 2011

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The use of flow splitters between the two dimensions in on-line comprehensive two dimensional liquid chromatography (LC×LC) has not received very much attention in comparison to their use in GC×GC where they are quite common. In principle, splitting the flow after the first dimension column and performing on-line LC×LC on this constant fraction of the first dimension effluent should allow the two dimensions to be optimized almost independently. When there is no flow splitting any change in the first dimension flow rate has an immediate impact on the second dimension. With a flow splitter one could for example double the flow rate into the first dimension column and do a 1:1 flow split without changing the sample loop size or the sampler’s collection time. Of course, the sensitivity would be diminished but this can be partially compensated by use of a larger injection; this will likely only amount to a small price to pay for this increased resolving power and system flexibility. Among other benefits, we found a 2-fold increase in the corrected 2D peak capacity and the number of observed peaks for a 15 min analysis time by using a post first dimension flow splitter. At a fixed analysis time this improvement results primarily from an increase in the gradient time resulting from the reduced system re-equilibration time and to a smaller extent it is due to the increased peak capacity achieved by full optimization of the first dimension.

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Section: Resultsmentioning

confidence: 99%

Improving Peak Capacity in Fast Online Comprehensive Two-Dimensional Liquid Chromatography with Post-First-Dimension Flow Splitting

et al. 2011

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“…[41] and discussed in more detail by Bailey et al [42] with reported concentrations for the average phenytoin concentration in waste water samples of 42 ± 1 ppb from the standard addition curve, 36 ± 1 ppb from the direct calibration curve (both calculated by manually integrating MCR-ALS-ssel components) and 42 ± 19 ppb by LC-LC MS/MS (all error ranges are given as 95 % confidence intervals). These calculated concentrations were similar to those obtained by directly summing the MCR-ALS-ssel components after careful application of the chromatographic selectivity constraint.…”

Section: 0 Results and Discussionmentioning

confidence: 99%

“…The introduction of small discrepancies between replicate injections, during the fitting step of the semiautomated alignment method, did not produce calibration curves as linear as those reported by Groskreutz et al . (R 2 = 0.988 for the standard addition and R 2 = 0.998 for the direct calibration) [41], as shown in Table 3. In addition to the irregular shifting of retention times between injections in the 2 D and 1 D, retention time shifting was observed within some of the injections.…”

Section: 0 Results and Discussionmentioning

confidence: 99%

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Semi-automated alignment and quantification of peaks using parallel factor analysis for comprehensive two-dimensional liquid chromatography–diode array detector data sets

Allen

Rutan

2012

Analytica Chimica Acta

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Parallel factor analysis was used to quantify the relative concentrations of peaks within four-way comprehensive two dimensional liquid chromatography-diode array detector data sets. Since parallel factor analysis requires that the retention times of peaks between each injection are reproducible, a semi-automated alignment method was developed that utilizes the spectra of the compounds to independently align the peaks without the need for a reference injection. Peak alignment is achieved by shifting the optimized chromatographic component profiles from a three-way parallel factor analysis model applied to each injection. To ensure accurate shifting, components are matched up based on their spectral signature and the position of the peak in both chromatographic dimensions. The degree of shift, for each peak, is determined by calculating the distance between the median data point of the respective dimension (in either the second or first chromatographic dimension) and the maximum data point of the peak furthest from the median. All peaks that were matched to this peak are then aligned to this common retention data point. Target analyte recoveries for four simulated data sets were within 2 % of 100 % recovery in all cases. Two different experimental data sets were also evaluated. Precision of quantification of two spectrally similar and partially coeluting peaks present in urine was as good as or better than 4 %. Good results were also obtained for a challenging analysis of phenytoin in waste water effluent, where the results of the semi-automated alignment method agreed with the reference LC-LCMS/MS method within the precision of the methods.

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“…This reduces the likelihood that an interfering peak, whether known or unknown, will be overlapped with the peak for a target analyte that is being quantified, which would lead to an overestimation of the concentration of the target analyte (Bailey et al, 2012). On the other hand, even when highly selective detection is used (e.g., high-resolution MS or tandem MS) the potential for additional separation and/or selectivity provided by a 2D method can improve accuracy by reducing matrix effects Groskreutz et al, 2012b;Pascoe et al, 2001). This is especially valuable in cases where isotope-labeled standards are either not available or prohibitively expensive, as the elimination of matrix effects enables achievement of good accuracy when using external standards for signal calibration .…”

Section: Data Analysis Software and Quantitation 275mentioning

confidence: 99%

Theory and Practice of UHPLC and UHPLC–MS

Guillarme

Veuthey

2017

Handbook of Advanced Chromatography /Mass Spectrometry Techniques

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Selective comprehensive multidimensional separation for resolution enhancement in high performance liquid chromatography. Part II: Applications

Cited by 41 publications

References 23 publications

Improving Peak Capacity in Fast Online Comprehensive Two-Dimensional Liquid Chromatography with Post-First-Dimension Flow Splitting

Improving Peak Capacity in Fast Online Comprehensive Two-Dimensional Liquid Chromatography with Post-First-Dimension Flow Splitting

Semi-automated alignment and quantification of peaks using parallel factor analysis for comprehensive two-dimensional liquid chromatography–diode array detector data sets

Theory and Practice of UHPLC and UHPLC–MS

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