The present disclosure is directed to methods of characterizing a system containing a chromatographic column. The methods can include introducing a sample comprising a positive control and a negative control to the system containing a chromatographic column, wherein the positive control is a sensitive probe that interacts with the system and the negative control is substantially non-interacting with the system; after passing the sample through the chromatographic column, detecting the positive control and the negative control; and determining system suitability by comparing the amount of detected positive control to negative control. In some embodiments, determining system suitability (e.g., inertness of sample to the system) is accomplished by determining a ratio of detected positive control to negative control.

The invention provides a liquid chromatograph mass spectrometer which prevents contamination of a pump and a column and can perform mass calibration without adding a complicated mechanism. This liquid chromatograph mass spectrometer includes a liquid chromatograph including a liquid feed pump configured to feed a mobile phase solvent, a mass spectrometer configured to analyze a mass of a sample, and a standard sample container configured to be connected in series with the liquid chromatograph and the mass spectrometer in a flow path that connects the liquid chromatograph and the mass spectrometer and configured to house a standard sample for mass calibration.

Certain configurations of devices and systems which are configured to draw a selected volume of an air sample into a trap are described. In some examples, the devices and systems comprise a pump and a mass flow sensor to draw a selected volume of the air sample through a trap even where variable restriction occurs.

The present disclosure provides devices, systems, kits and methods useful for quantitation of biomolecules such as intact proteins and nucleic acids.

To increase the difference between the thermal conductivity of the carrier gas and the thermal conductivity of each component of the sample gas. The analysis method is an analysis method that performs analysis using a gas chromatograph including a thermal conductivity detector. The analysis method includes introducing a carrier gas and a sample gas into a separation column, introducing the sample gas separated in the separation column into a gas introduction chamber including an element having an electrical characteristic changed by temperature, detecting a change in the electrical characteristic of the element due to the sample gas being introduced, and switching the carrier gas from a first carrier gas to a second carrier gas that is a different type from the first carrier gas, while a component of the sample gas is passing through the separation column.

An electrical conductivity detector includes a cell through which a liquid flows, a measurement part for obtaining an electrical conductivity signal which is a current corresponding to an electrical conductivity of the liquid flowing through the cell, a phase adjustment value holder that holds a phase adjustment value which is a predetermined shift amount between a phase of the electrical conductivity signal and a phase of a measurement voltage applied to the cell by the measurement part, a BG subtraction signal generator configured to generate a BG subtraction signal for removing a background component included in the electrical conductivity signal obtained by the measurement part, the BG subtraction signal being adjusted to have a phase substantially identical to the phase of the electrical conductivity signal using the phase adjustment value held in the phase adjustment value holder, an addition part configured to add the electrical conductivity signal and the BG subtraction signal with each other, and a calculation part configured to calculate the electrical conductivity of the liquid flowing through the cell using a signal output from the addition part.

Methods are described for detecting or determining the amount of antidepressants and/or antidepressant metabolites in a sample. More specifically, mass spectrometric methods are described for detecting and quantifying antidepressants and/or antidepressant metabolites in a sample.

An improved version of the capillary bridge viscometer that compensates for the effect of solvent compressibility is disclosed. A novel, yet simple and inexpensive modification to a conventional capillary bridge viscometer design can improve its ability to reject pump pulses by more than order of magnitude. This improves the data quality and allows for the use of less expensive pumps. A pulse compensation volume is added such that it transmits pressure to the differential pressure transducer without sample flowing there through. The pressure compensation volume enables the cancellation of the confounding effects of pump pulses in a capillary bridge viscometer.

An improved version of the capillary bridge viscometer that compensates for the effect of solvent compressibility is disclosed. A novel, yet simple and inexpensive modification to a conventional capillary bridge viscometer design can improve its ability to reject pump pulses by more than order of magnitude. This improves the data quality and allows for the use of less expensive pumps. A pulse compensation volume is added such that it transmits pressure to the differential pressure transducer without sample flowing there through. The pressure compensation volume enables the cancellation of the confounding effects of pump pulses in a capillary bridge viscometer.

Methods are provided for making rapid labeled dextran ladders and other calibrants useful in liquid chromatography. The methodologies include a two-step process comprising a reductive amination step of providing a reducing glycan and reacting it with a compound having a primary amine to produce an intermediate compound. The intermediate compound is then rapidly tagged with a rapid tagging reagent to produce the rapid labeled dextran ladder.