Sichuan University

Xiaoping Jiang

Xinshen Zhang

Nan Li

Lingyun Yu

The invention relates to an apparatus for simultaneous online assay of nitrites and nitrates in water samples with improved sensitivity and accuracy, enhanced capacity of anti-interference against salinity, reduced assay costs, and simplified operation.

Method and apparatus for simultaneous online assay of nitrites and nitrates in water samples

A method for assaying anionic detergents in seawater comprises: (1) flow a sample through a sample system and an analysis-detection system; flow a reference solution through a reference system, a valve, and the analysis-detection system; where the sample and reference are mixed; and flow the mixture into an optical cell to produce a baseline, (2) flow a sample through the sample system and analysis-detection system; flow a buffer through a buffer system and a color developing system; where the buffer and a color developer are mixed; and flow the resulting mixture through the valve and analysis-detection system; where the sample is mixed with the buffer and developer mixture; and flow the resulting mixture into the cell to produce the sample spectrogram, (3) repeat (1) and (2) with standards of known detergent concentrations for corresponding spectrograms, and (4) compare the sample spectrogram with the standard spectrograms to determine the sample detergent content.

Method for automatic assay of anionic detergents in seawater

A process for simultaneous assay of chlorides and sulfides by low pressure ion exclusion chromatography is provided, and in said process an analytic apparatus comprising a sampling valve, a sampling loop, an ion exclusion column and an analytic detection flow path is used, and said process comprises the following steps: (1) in the analytic detection flow path, the mixture of developer Rand developer Rmixes with Eluent C and then enters into a reactor, and the mixing is continued under heating. The resulting mixture flows into the optical flow cell and a baseline is mapped accordingly; (2) a testing sample S flows into the sampling loop through a sample flow path and the sampling valve, and under the drive of Eluent C, flows into the ion exclusion column from the sampling loop, and enters into the analytic detection flow path through the ion exclusion column; developer Rand developer Reach enter into the analytic detection flow path through respective developer flow path and mix with each other in the analytic detection flow path. The mixture of developer Rand developer Rmixes with the Eluent C carrying the testing sample and then enters into the reactor, and the mixing is continued under heating and a reaction takes place. The reacted mixture flows into the optical flow cell and a spectrogram of the testing sample is mapped accordingly.

Simultaneous analysis of chlorides and sulfides by low pressure ion exclusion chromatography

A concentrating column useful for elemental analysis of trace metals consists mainly of column body, filtration membranesfixed at the fluid inlet end and the outlet end of the column body, and column packingpacked inside the column body, wherein column packingis prepared from the swollen and cleaned macroporous adsorbent resin of high, medium or non-polarity treated with a mixture of 3 mol/L NHOH-1 mol/L HAC-3.0&#x2dc;6.0&#xd7;10mol/L pyridin-(2-azo-4-)resorcin or a mixture of 0.5 mol/L NaHPO-1.0&#x2dc;2.0&#xd7;10mol/L pyridin-(2-azo-4-)resorcin by dynamic on-column treatment or static immersion treatment. Two types of sample processing devices useful for elemental analysis of trace metals are provided with concentrating column employing the above-mentioned column packing. The concentrating column of the present invention simplifies the sample processing flow and the structure of sample processing device, saves chemical reagent, increases sample processing rate, and particularly prevents the toxic methanol from doing harm to the operator's health.

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Chengdu, China

Xiaoping Jiang