JPS62140042A - Concentrator - Google Patents

Abstract

PURPOSE:To achieve the enhancement of the sensitivity in flow analysis, by introducing aqueous ammonia between a large capacity column and an ion change column. CONSTITUTION:A specimen solution containing an element to be analyzed and a matrix element obstructing the measurement is introduced from a specimen introducing port (a) and passes through a large capacity ion exchange column (c) to adsorb only the element to be analyzed while the matrix element is discharged from a valve (d). Next, an eluent (k) is introduced in the column (c) using a pump in order to move the element to be analyzed to a low capacity ion exchange column (h) and aqueous ammonia (l) is added to the specimen solution between the column (c) and a large capacity anion exchange column or exchange membrane (f) to make the liquidity introduced into the exchange membrane (f) ammonia-akaline. By this method, a heavy metal forming an ammine complex ion is conc. in the column (h) without being sedimented. Next, an eluent (m) is introduced to elute only the element to be analyzed adsorbed by the column (h) and said element is guided to a detector (j) to perform detection.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a concentrating device for trace elements using an ion exchange method, and particularly to a concentrating device suitable for concentrating metal ions forming ammine complex ions.

[Background of the invention]

Conventionally, in order to increase sensitivity, elements that have been adsorbed onto an ion exchange resin have not been eluted and adsorbed onto a low capacity ion exchange column. However, 1 analytical chemistry (An
al, Chem) 16, 221-225 (1984
) As shown in 1. In ion chromatography, there is an example in which only specific ions separated by a separation column are passed through a detector and then concentrated in a concentration column. In this case, since the analysis is of anions, no special considerations are required; just a connection is required.

[Purpose of the invention]

An object of the present invention is to provide a concentration device using an ion exchange method for trace elements in order to achieve high sensitivity in flow analysis and the like.

[Summary of the invention]

When trace elements are concentrated using an ion exchange column and continuously guided to a detector, if the column has a large capacity, the peaks will be broad. In order to obtain high sensitivity, it is necessary to reconcentrate on a low-capacity column, but in the case of metal ions, if the acid concentration during re-adsorption is lowered using an ion exchange column, hydroxides will precipitate, making it impossible to achieve the objective. Therefore, by adding ammonia before lowering the acid concentration, copper, zinc, nickel, cobalt, etc. are stabilized as ammine complex ions even in alkaline conditions and are re-adsorbed.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIG. First, a sample solution containing an element to be analyzed (metal ion) and a matrix element that interferes with measurement is introduced through the sample introduction port (a) in the drawing row. The sample passes through a large capacity ion exchange column (c), where only the target element is adsorbed, and the matrix is discharged through a valve (d). Next, the eluent (
J) is introduced into column (c) using pump O. When the target element is a metal ion, a cation exchange resin is used as the column (c), and an acid is mainly used as the eluent (K). Here, it is assumed that hydrochloric acid (HCI) is used. The target element and the eluent pass through a large-capacity anion-exchange column or an equivalent anion-exchange membrane (f), where they become neutral or alkaline, and are introduced into a low-volume concentration column (h). At this time, metals other than alkali metals and alkaline earth metals, such as heavy metals, reduce the concentration of hydrogen ions in the solution, producing hydroxides with low solubility and becoming precipitates, which cannot be collected in (h). . Therefore, in this example, aqueous ammonia (Q) was added to the sample solution between the large capacity cation exchange column (c) and the large capacity anion exchange column or exchange membrane (f).
The liquid introduced in step f) is ammonia alkaline.

By doing this, heavy metals (copper, zinc, nickel, etc.) that form ammine complex ions.

Cobalt) etc. are concentrated in the low capacity cation exchange column (h) without precipitation.

Next, an eluent (m) is introduced to elute only the target element adsorbed to (h), and the eluent is guided to a detector (j) for detection.

〔Effect of the invention〕

According to the present invention, metals such as copper, zinc, and nickel can be concentrated in low capacity ion exchange columns.

Since peak broadening can be significantly reduced compared to the case of using conventional large capacity ion exchange columns, ultratrace analysis becomes possible.

[Brief explanation of drawings]

FIG. 1 shows a block diagram of the apparatus.

Claims (1)

[Claims] In a continuous ion exchange concentration system consisting of a large capacity column for sample concentration, an ion exchange column for removing anions in the eluent, and a low capacity column for sample reconcentration, ammonia is placed between the large capacity column and the ion exchange column. A concentrating device for ultratrace metal ions, characterized by being equipped with a device for introducing water.