摘要:
A degas assembly including a low pressure fluid channel for carrying a wash fluid at a first pressure, a pressurized channel for carrying eluent including a gas at a second pressure higher than the first pressure, and a degas separator defining a fluid barrier between the low pressure fluid channel and pressurized fluid channel, the separator configured to retain liquid in the pressurized fluid channel and allow gas to flow through the separator to the low pressure fluid channel. The pressurized fluid channel may extend along an outer periphery of the low pressure fluid channel. The eluent may be received from an eluent generator at a pressure of at least about 3300 psi, and in various embodiments up to about 5000 psi. A liquid chromatography system and method are also disclosed.
摘要:
A degas assembly including a low pressure fluid channel for carrying a wash fluid at a first pressure, a pressurized channel for carrying eluent including a gas at a second pressure higher than the first pressure, and a degas separator defining a fluid barrier between the low pressure fluid channel and pressurized fluid channel, the separator configured to retain liquid in the pressurized fluid channel and allow gas to flow through the separator to the low pressure fluid channel. The pressurized fluid channel may extend along an outer periphery of the low pressure fluid channel. The eluent may be received from an eluent generator at a pressure of at least about 3300 psi, and in various embodiments up to about 5000 psi. A liquid chromatography system and method are also disclosed.
摘要:
A continuous electrochemical pump comprising a water generator compartment, an anode compartment on one side of said generator compartment, a cation exchange barrier, separating the generator compartment from the anode compartment, it first electrode in electrical communication with the anode compartment, a cathode compartment adjacent the generator chamber, an anion exchange barrier, separating the generation compartment from the cathode compartment, and a second electrode in electrical communication with the cathode compartment. Use of the pump as a sample concentrator. A feedback loop for the pump. A reservoir, with or without an intermediate piston, on the output side of the pump.
摘要:
Method and apparatus for generating an acid or base, e.g. for chromatographic analysis of anions. For generating a base the method includes the steps of providing a cation source in a cation source reservoir, flowing an aqueous liquid stream through a base generation chamber separated from the cation source reservoir by a barrier (e.g. a charged membrane) substantially preventing liquid flow while providing a cation transport bridge, applying an electric potential between an anode cation source reservoir and a cathode in the base generation chamber to electrolytically generate hydroxide ions therein and to cause cations in the cation source reservoir to electromigrate and to be transported across the barrier toward the cathode to combine with the transported cations to form cation hydroxide, and removing the cation hydroxide in an aqueous liquid stream as an effluent from the first base generation chamber. Suitable cation sources include a salt solution, a cation hydroxide solution or cation exchange resin.
摘要:
Method and apparatus for ion chromatography including passage of sample through a chromatographic separation column, through a suppressor column containing a resin with exchangeable ions, and then through a detector. The suppressor column is equipped with an electrical potential supplying device to electrolyze water and regenerate the suppressor column.
摘要:
An ion chromatography method for analysis of a plurality of analyte ions in a sequence of samples in which ion chromatography is performed on a sample, which is passed to a non-precipitating suppressor ion exchange resin and analyzed, the suppressor being regenerated in one step prior to processing of a subsequent sample.
摘要:
Apparatus and method for the chromatographic separation and analysis of ionic species. This process is carried out utilizing, in an ion separator column, the combination of a low capacity, high performance resin as the stationary phase, and a weakly ionized electrolyte as the eluant or developing reagent, to effect resolution of ionic species in solution. For anion separation, a weak base resin of low capacity and high efficiency is used as the stationary phase, and a solution of a weak base or water as the mobile phase. For cation separation, a weak acid resin of low capacity and high efficiency is used as the stationary phase and a solution of a weak acid as the mobile phase. Because the eluant employed has a very low background conductivity, it will register only insignificantly on the readout from the conductivity cell. Thus, the method of the invention obviates the need for the eluant suppressor or "stripper" device used in conventional ion chromatography. The invention thereby enables continuous, uninterrupted measurements and eliminates the reservoirs, pumps, complex valving and electronics associated with such suppressor columns.
摘要:
Apparatus for accurately metering liquid flow based on the injection of a brief heat pulse into the flowing stream, e.g., via a miniature thermistor, and detection of an electronic time derivative of temperature downstream with, e.g., a second microprobe thermistor. This detection triggers a subsequent heat pulse and the cycle repeats, with pulse total corresponding to elapsed liquid throughput, and pulse frequency to flow rate.
摘要:
A method and apparatus for generating an acid or base eluent in an aqueous stream solely from an ion exchange bed for liquid chromatography of anions or cations and for simultaneously suppressing conductivity of the eluent in the ion exchange bed after chromatographic separation. For a system in which a base is generated for the analysis of anions by ion chromatography, the method uses a bed of cation exchange material with first and second bed sections arranged in series. For anion analysis, the method includes:(a) flowing an aqueous feed stream through the first bed section while applying an electrical potential to form an aqueous eluent stream comprising a cation hydroxide base,(b) flowing a liquid sample stream containing anions to be detected and the eluent through a chromatographic separator portion of said first bed section, to separate said anions to be detected,(c) flowing said aqueous separated anion stream through said second bed section substantially free of anion exchange material and including exchangeable hydronium ions, while applying an electrical potential to convert said base to weakly ionized form, and displacing some of said exchangeable hydronium ions with cations from said base, cations electromigrating from said second bed section to said first bed section in the opposite direction to said aqueous feed stream to replenish exchangeable cations displaced from said first bed in step (a), and(d) flowing said suppressor effluent stream past a detector in which the separated anions in said suppressor effluent are detected.
摘要:
An improved technique for the measurement of ions in solution where the ions of interest are chromatographically displaced from an ion exchange column by an eluting ion which is or is made light-absorbing, and where the eluted sample ions, which are transparent (at the monitored wavelength), are detected and quantified from the decrements they cause in effluent absorbance as revealed by photometric monitoring.