An MFC includes: a proportional valve; a mass flow sensor; a first flow line connecting from an outlet of the proportional valve through the mass flow sensor to an exit line; a second flow line joining the first flow line at a first junction located upstream of the mass flow sensor and at a second junction located downstream of the mass flow sensor; a switching valve placed such that the switching valve can regulate a flow of a gas through the first flow line or the second flow line; and a control device connected to provide a feedback control loop for regulating the proportional valve based on signals measured by the mass flow sensor, wherein the control device includes a program for keeping a rate of a flow exiting the exit line substantially constant when the flow is through the second flow line.

An MFC includes: a proportional valve; a mass flow sensor; a first flow line connecting from an outlet of the proportional valve through the mass flow sensor to an exit line; a second flow line joining the first flow line at a first junction located upstream of the mass flow sensor and at a second junction located downstream of the mass flow sensor; a switching valve placed such that the switching valve can regulate a flow of a gas through the first flow line or the second flow line; and a control device connected to provide a feedback control loop for regulating the proportional valve based on signals measured by the mass flow sensor, wherein the control device includes a program for keeping a rate of a flow exiting the exit line substantially constant when the flow is through the second flow line.

The present invention relates to a chromatography system and a method therefor. The chromatography system comprising an inlet port (102) for receiving a sample, an outlet port (106) for delivering the sample, a detector (201), a column (104), and a valve (202) in fluid communication with the inlet port, the outlet port, the detector, and the column. The valve (202) comprises a first position (304) wherein the inlet port is in fluid communication with the outlet port via a first fluid path comprising the detector and the column, wherein the detector is arranged upstream the column. The valve comprises a second position (404) wherein the inlet port is in fluid communication with the outlet port via a second fluid path comprising the detector and the column, wherein the detector is arranged downstream the column.

The present invention concerns the preparation of solutions, particularly for implementing analytical methods, in particular by spectrometry, particularly for producing standard solutions which are useful, for example, for calibrating spectrometers or for implementing diagnostic methods. It allows the implementation of an easy process for preparing such standard solutions.

Described are techniques for performing automated maintenance evaluations on a gas chromatograph (GC) or a gas chromatograph-mass spectrometer (GC-MS). Systems and methods are described for directing an injector of a GC or GC-MS instrument system to autonomously inject a diagnostic material sample into a material analysis chamber and initiate a scientific analysis to formulate a set of results. The systems and methods further include the instrument system analyzing the set of results generating one or more output reports.

A Gas Chromatograph (GC) detector comprises a first circuit, a second circuit, a digital subtractor and a digital logic shared between one to many detector channels to provide a GC measurement in a digital form. The first circuit includes a first counter circuitry to provide a first counter output. The second circuit includes a second counter circuitry to provide a second counter output. The GC detector includes a digital subtractor to subtract the first counter output from the second counter output and provide a digital subtractor output. The GC detector further includes a digital logic shared between one to many detector channels to implement at least a portion of the first counter circuitry and the second counter circuitry. The digital logic to receive the digital subtractor output and provides the GC measurement in the digital form. The GC detector may be based on a Thermal Conductivity Detector (TCD) in which an integrator of a Sigma-Delta (Σ-Δ) A/D converter is eliminated and the Σ factor of the Sigma-Delta (Σ-Δ) A/D converter is accomplished in a digital form.

The present application concerns a process for quantifying polysorbates in a sample by implementing a LC-MS analysis with an internal standard, and the process for monitoring degradation of polysorbates in such sample.

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.

The present application concerns a process for quantifying polysorbates in a sample by implementing a LC-MS analysis with an internal standard, and the process for monitoring degradation of polysorbates in such sample.

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.