### Abstract

The dilution of analytes during their migration through two-dimensional liquid chromatographic systems was investigated. Simplified equations for the calculation of the dilution factors in the first and second dimension columns were derived considering the variance of the injected sample, the flow rates, the split ratio, the volume of the intermediate sample loop and the sampling time of the first-dimension effluent. The net dilution factor is the product of the dilution factors in the two single dimensions. It is between 200 and 300 in typical two-dimensional liquid chromatographic (2D-LC) separations. These values are less pessimistic than those reported previously [1]. It was shown that the fraction of organic modifier or stronger eluent component in the injected sample has a significant effect on the widths and heights of the eluted peaks. Analytes with high retention factors and high molecular weights are less sensitive toward this effect than those having small retention factors. These results suggest that the optimization of the experimental conditions of two dimension separations must be made from the points of view of both the retention factor and the detector response factor. The frequency of sampling of the eluent of the first-dimension separation does not have a significant effect on the detection limit of a 2D system if the split ratio is adjusted in the ratio of the frequency of sample collection.

Original language | English |
---|---|

Pages (from-to) | 7785-7792 |

Number of pages | 8 |

Journal | Journal of Chromatography A |

Volume | 1216 |

Issue number | 45 |

DOIs | |

Publication status | Published - Nov 6 2009 |

### Fingerprint

### Keywords

- Detection
- Detection limit
- Dilution factor
- On-line two-dimensional chromatography
- Two-dimensional chromatography

### ASJC Scopus subject areas

- Analytical Chemistry
- Organic Chemistry
- Biochemistry

### Cite this

*Journal of Chromatography A*,

*1216*(45), 7785-7792. https://doi.org/10.1016/j.chroma.2009.09.016

**Detection issues in two-dimensional on-line chromatography.** / Horváth, K.; Fairchild, Jacob N.; Guiochon, Georges.

Research output: Contribution to journal › Article

*Journal of Chromatography A*, vol. 1216, no. 45, pp. 7785-7792. https://doi.org/10.1016/j.chroma.2009.09.016

}

TY - JOUR

T1 - Detection issues in two-dimensional on-line chromatography

AU - Horváth, K.

AU - Fairchild, Jacob N.

AU - Guiochon, Georges

PY - 2009/11/6

Y1 - 2009/11/6

N2 - The dilution of analytes during their migration through two-dimensional liquid chromatographic systems was investigated. Simplified equations for the calculation of the dilution factors in the first and second dimension columns were derived considering the variance of the injected sample, the flow rates, the split ratio, the volume of the intermediate sample loop and the sampling time of the first-dimension effluent. The net dilution factor is the product of the dilution factors in the two single dimensions. It is between 200 and 300 in typical two-dimensional liquid chromatographic (2D-LC) separations. These values are less pessimistic than those reported previously [1]. It was shown that the fraction of organic modifier or stronger eluent component in the injected sample has a significant effect on the widths and heights of the eluted peaks. Analytes with high retention factors and high molecular weights are less sensitive toward this effect than those having small retention factors. These results suggest that the optimization of the experimental conditions of two dimension separations must be made from the points of view of both the retention factor and the detector response factor. The frequency of sampling of the eluent of the first-dimension separation does not have a significant effect on the detection limit of a 2D system if the split ratio is adjusted in the ratio of the frequency of sample collection.

AB - The dilution of analytes during their migration through two-dimensional liquid chromatographic systems was investigated. Simplified equations for the calculation of the dilution factors in the first and second dimension columns were derived considering the variance of the injected sample, the flow rates, the split ratio, the volume of the intermediate sample loop and the sampling time of the first-dimension effluent. The net dilution factor is the product of the dilution factors in the two single dimensions. It is between 200 and 300 in typical two-dimensional liquid chromatographic (2D-LC) separations. These values are less pessimistic than those reported previously [1]. It was shown that the fraction of organic modifier or stronger eluent component in the injected sample has a significant effect on the widths and heights of the eluted peaks. Analytes with high retention factors and high molecular weights are less sensitive toward this effect than those having small retention factors. These results suggest that the optimization of the experimental conditions of two dimension separations must be made from the points of view of both the retention factor and the detector response factor. The frequency of sampling of the eluent of the first-dimension separation does not have a significant effect on the detection limit of a 2D system if the split ratio is adjusted in the ratio of the frequency of sample collection.

KW - Detection

KW - Detection limit

KW - Dilution factor

KW - On-line two-dimensional chromatography

KW - Two-dimensional chromatography

UR - http://www.scopus.com/inward/record.url?scp=70349816659&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=70349816659&partnerID=8YFLogxK

U2 - 10.1016/j.chroma.2009.09.016

DO - 10.1016/j.chroma.2009.09.016

M3 - Article

C2 - 19800627

AN - SCOPUS:70349816659

VL - 1216

SP - 7785

EP - 7792

JO - Journal of Chromatography

JF - Journal of Chromatography

SN - 0021-9673

IS - 45

ER -