CROSS-REFERENCE TO RELATED APPLICATIONS

Not applicable.

BACKGROUND

1. Technical Field

The present disclosure relates generally to systems and methods for concentrating an analyte preparatory to analysis thereof. In particular, the present disclosure relates to methods for processing the effluent of an analyte concentrator to produce an eluent for eluting the analyte retained in the same or separate concentrator, and to systems implementing the same. The present disclosure further relates to an analyte concentrator system that connects the effluent outlet of an analyte concentrator to an eluent generation module, and to methods implementing the same.

2. Related Technology

In existing analyte concentrator systems (or columns), a fluid sample containing at least one analyte molecule of interest is introduced into an analyte concentrator column that retains at least some of the analyte molecules in the fluid sample. After washing any un-retained fluid sample or constituents thereof from the column, the retained analyte molecules are eluted from the column in a concentrated volume relative to the original fluid sample. For instance, an eluent having a chemical composition adapted for eluting the retained analyte molecules can be introduced into the column to elute the retained analyte. In this way, a fluid sample having a low concentration of analyte molecules can be concentrated for more robust analysis of the analyte.

FIG. 1is a flowchart diagram illustrating a prior art analyte concentrator system8as known to those skilled in the art. As depicted inFIG. 1, an analyte sample10is introduced via input line12into an analyte concentrator14. Analyte concentrator14is configured to retain one or more analyte molecules of interest contained in analyte sample10. Accordingly, the analyte is retained in analyte concentrator14, while the fluid sample effluent is discharged via output line16to waste18.

A wash fluid20may also be optionally introduced via input line22into analyte concentrator14. Wash fluid20is configured to remove any un-retained sample (e.g., sample fluid or molecular component thereof) from analyte concentrator14. The wash effluent is also discharged via output line16to waste18.

After washing analyte concentrator14, an eluent24is introduced into analyte concentrator14. Eluent24is chemically configured to elute the analyte retained in analyte concentrator14. The eluted analyte molecules of interest are then discharged from analyte concentrator14(as a concentrated analyte sample) via output line28and introduced into analyte detector30for analysis.

One drawback to prior art system8and other existing concentrator systems is the presence of analyte molecules and/or contaminants in the wash fluid20and/or the eluent24. Indeed, the wash fluid20and/or eluent24may include the very analyte sought to be analyzed in analyte detector30. Even wash fluid and/or eluent generated from ultra-pure or nano-filtered water may not be entirely or even substantially free of the analyte molecules of interest. Thus, the amount or concentration of analyte eluted from analyte concentrator14may not represent the actual amount of analyte in analyte sample10. Instead, analyte concentrator14may have retained the analyte molecules contained in wash fluid20. In addition, the eluent itself may include analyte molecules; adding to the amount of analyte molecules present in the eluted analyte sample. Further, the eluent may include ionic contaminants from the water source that interfere with the analyte measurement. These additional sources of analyte molecules in the concentrated analyte sample can adulterate the sample and alter the analytical results.

Subtractive normalization or other techniques may be used to remove analytical (background) noise caused by analyte or ionic contaminants in the eluent and/or wash fluid. However, if the analyte sample only contained trace amounts (e.g., on the order of parts-per-billion (ppb) or even parts-per-trillion (ppt)) of the analyte molecules of interest, the background signal (or noise) from the additional analyte molecules in the eluent and/or wash fluid may overwhelm the analyte signal and negate accurate, quantitative measurement of the concentrated analyte molecules of interest.

Accordingly, it would be beneficial to provide systems and methods for concentrating an analyte using a eluent that is substantially free of the analyte molecule(s) of interest or ionic contaminants (e.g., to minimize and/or (substantially) eliminate background signal during analysis of the concentrated analyte).

