Quantitative Evaluation of Chromatograms By Digital Computers

Baumann, Fred; Herlicska, Edward; Brown, Angus M.; Blesch, John

doi:10.1093/chromsci/7.11.680

Cited by 24 publications

(12 citation statements)

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“…Optimum splitless time was examined by the evaluation of the obtained peak areas of n-alkanes C 16 , C 20 , C 22 , C 26 and C 28 at different splitless time in the range of 0.05 -2.00 min. Single tapered liner (I.D.…”

Section: Speed Resolution and Separation Efficiencymentioning

confidence: 99%

“…In the literature there are general discussions concerning how many data points are actually needed to define the chromatographic peak; the values in the ranges of 15 -20 were found to be the minimum for the accurate representation of a peak [25], but in other papers [12,26,27] also three to four data points are published that work well enough for quantitative analysis. For the FID and ECD utilized, data acquisition rate was 50 Hz.…”

Section: Detectionmentioning

confidence: 99%

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Possibilities and limitations of fast GC with narrow‐bore columns

Dömötörová

Kirchner

Matisová³

et al. 2006

J of Separation Science

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In this work, two narrow-bore capillary columns with different internal diameters (I.D.) 0.15 mm (15 m length, 0.15 microm film thickness) and 0.10 mm (10 m length, 0.10 microm film thickness) with the same stationary phase (5% diphenyl 95% dimethylsiloxane), phase ratio and separation power were compared with regard to their advantages, practical limitations and applicability in fast GC on commercially available instrumentation. The column comparison concerns fast GC method development, speed and separation efficiency, the sample transfer into the column utilizing split and splitless inlet, sample capacity, detection (analysing compounds of a wide range of polarities and volatilities--even n-alkanes C16-C28 and selected pesticides) and ruggedness (in the field of ultratrace analysis of pesticide residues in real matrix). Under conditions corresponding to speed/separation efficiency trade-off 0.10 mm I.D. versus 0.15 mm I.D. column provides a speed gain of 1.74, but all other parameters investigated were better for the 0.15 mm I.D. column concerning more efficient sample transfer from inlet to the column using splitless injection, no discrimination with split injection. Better sample capacity (three times higher for the 0.15 mm than for the 0.10 mm I.D. column) resulted in improved ruggedness and simpler fast GC-MS method development.

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Section: Speed Resolution and Separation Efficiencymentioning

confidence: 99%

Section: Detectionmentioning

confidence: 99%

Possibilities and limitations of fast GC with narrow‐bore columns

Dömötörová

Kirchner

Matisová³

et al. 2006

J of Separation Science

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“…The effect of sampling frequency on accuracy and precision in the measurement of transient signals has been extensively studied in analytical chemistry, in particular for chromatography. [1][2][3][4][5][6] Nevertheless, the relationship between the number of data points and the fidelity of monitoring transient signals remains an issue under debate. According to the Nyqvist theorem, at least 6 measurement points are required for the unbiased sampling of a perfect Gaussian peak.…”

Section: Introductionmentioning

confidence: 99%

“…According to the Nyqvist theorem, at least 6 measurement points are required for the unbiased sampling of a perfect Gaussian peak. 1 In reality, very few measured signals are perfectly Gaussian, and normally contain noise, and therefore it has been recommended to sample 5-30 [1][2][3][4][5] points per peak in order to obtain less than ¡0.1% error in the measured area for such a peak. Asymmetric peaks generally require more data points to obtain the same accuracy 5,6 and 15-350 data points per peak have been recommended 6 to obtain less than ¡0.1% error.…”

Section: Introductionmentioning

confidence: 99%

“…The increase in peak area error when fewer data points are sampled is, however, often moderate and it has been reported that, for a Gaussian peak, 5-6 data points per peak are sufficient to recover 99.97-100.03% of the area compared to 98.56-101.44% for 3-4 points per peak. 2 Transient signals are also common in atomic spectrometry, in particular for electrothermal atomisation atomic absorption spectrometry (ETAAS), but also in micro-sampling applications of inductively coupled plasma mass spectrometry (ICP-MS). Several important sample introduction systems used in ICP-MS give rise to transient signals, such as electrothermal vaporisation (ETV), laser ablation, flow injection (FI) analysis and all types of chromatographic hyphenations.…”

Section: Introductionmentioning

confidence: 99%

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Calibration errors due to variations in peak characteristics in the measurement of transient signals by inductively coupled plasma-scanning mass spectrometry

Björn

Baxter

Frech

2002

J. Anal. At. Spectrom.

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The impact of variations in peak characteristics on the fidelity of transient signal measurement by inductively coupled plasma-quadrupole mass spectrometry (ICP-QMS) was investigated. Specifically, the question as to whether the multi-element capabilities or the accuracy in determined analyte amounts were deteriorated compared to what has been reported previously when not considering peak variations was addressed. The peak characteristics considered were the time of the signal maximum (t peak ), the standard deviation of the assumed Gaussian input function generated by the sample introduction system (s G ), and the time constant for signal decay (t). Investigations of simulated exponentially-modified Gaussian peaks revealed that, for variations of peak characteristics within reasonable ranges, measurement noise and variations in t peak , s G and t all contributed to calibration uncertainty. Electrothermal vaporisation (ETV) and flow injection (FI) systems were used to experimentally generate transient signals of varying peak characteristics. Removing data points from the raw signals simulated the monitoring of up to 100 mass-to-charge ratios, allowing calibration data and analyte amounts to be determined from the processed signals. To obtain calibration graph slopes with relative standard deviations below 1% for the ETV-ICP-QMS system, it was found necessary to acquire 7-24 data points per peak for 50-5 ms dwell times. On this basis, the maximum number of mass-to-charge ratios that could be monitored in a typical ETV-ICP-QMS analysis was 4-10 using dwell times of 50-5 ms. With the FI-ICP-QMS system, variations in the peak characteristics between calibration standards and samples meant that, to obtain less than 3% error in determined analyte amounts, at least 7 or 10 points per peak were required for external and internal standardisation, respectively. It was found that variations in peak characteristics contributed more than measurement noise to the error in determined analyte amounts. In recent studies it has been reported that 3-4 data points per peak are sufficient to accurately monitor a transient if peak variations are not considered, which, for typical ETV signals, would allow the monitoring of 20 mass-to-charge ratios during a single measurement cycle. Thus the results obtained here show that the multi-element capability of ICP-QMS when monitoring transient signals can be severely compromised by such variations.

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Rechnersystem zur Erfassung und Auswertung physikalischer Analysen

Günzler

1970

Chemie Ingenieur Technik

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Menschen weiter, wenn ,,etwas aufierhalb der Norm lieyt, wenn etmas Besonderes" anaefallen ist. Die anstrenaende Literatur c an denen man heute schon zum Teil arbeitet, bald in aller Breite uncl preiswert verfiigbar sind. [4] W . R. Fuchs, Informationstheorie und Kybernetik, Droeniersche Verlagsanstalt Th. Knaur Nachf., Munchen 196Y. [5] K . Bieman)t, P. I-. Fcnnessey, Chimia [Aarau, Rchmeiz] 21. 226 [1967].

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Quantitative Evaluation of Chromatograms By Digital Computers

Cited by 24 publications

References 0 publications

Possibilities and limitations of fast GC with narrow‐bore columns

Possibilities and limitations of fast GC with narrow‐bore columns

Calibration errors due to variations in peak characteristics in the measurement of transient signals by inductively coupled plasma-scanning mass spectrometry

Rechnersystem zur Erfassung und Auswertung physikalischer Analysen

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