RA-4300A – Fully automated mercury analysis using CV-AAS

The RA-4300A enables fast and easy determination of mercury down to the ultra trace level in aqueous and digested samples.

The sustainable solution for mercury analysis

The RA-4300A is a measuring system for mercury analysis by means of reducing vapourisation (CVAAS), which is equipped with all the crucial functions to meet the requirements of mercury analysis.

The 80-position autosampler included in the equipment maximises sample throughput in any laboratory and delivers results in the shortest possible time. Even after a standstill, the system is ready to measure in just a few minutes.

The RA-4300A is equipped with a non-dispersive CVAAS that has a detection limit of up to 0.5 ppt (5 ppt when digestion blank values are taken into account) with excellent accuracy and precision. With this superior detection limit and excellent precision, the RA-4300A can cover a wide range of applications.

Basically, there are two methods that work with reducing mobilisation of mercury: Flow injection technique or discrete analysis by mobilisation directly from the receiver/sample vessel. All NIC mercury analysers use discrete and direct mobilisation (batch method) to minimise carry-over of mercury. In this way, even large concentration differences (the measuring range extends up to 100ppb) or unexpectedly high contents (automatic protection function) can be processed robustly and automatically in routine without downtime.

The technology used also makes the RA-4300 particularly robust when processing samples that contain particles or lead to difficulties due to other sample properties in a classic flow system with gas-liquid separation: the reagents are added directly to the respective sample vessel by the analyser and mixed with the sample. The reduced mercury is expelled from the sample with purified air and transferred to the detector cell. The sample itself remains in the sample vessel during the entire measurement.

The RA-4300A was developed with a focus on sustainable operation and low operating costs: no carrier gas, such as nitrogen or argon, is required. Also the very small quantities of reagents, which are added directly to the respective sample vessel by the analyser, reduce waste and costs and guarantee absolute purity of the reagents, which plays a decisive role in the analysis of mercury traces.

The reagent pumps and reagent dosing system used are durable and deliver reagents such as hydroxylamine hydrochloride, stannous chloride and sulphuric acid with excellent precision. The entire process of removing excess oxidant and mobilising the mercury is automated.

Figure 1: RA-4300A.

Key features

– CVAAS system for mercury determination

– Discrete analysis from the receiver vessel / batch method

– Minimal carry-over, large measuring range, low susceptibility to particles

– Excellent analytical performance over a wide measuring range

– Autosampler with 80 positions (can be reloaded during operation)

– Low operating and consumable costs

– High safety (control functions, enclosure with suction function)

– Easy handling and intuitive software

– Low space requirement

– Fully enclosed and equipped with an exhaust system

Parameters / Elements

– Mercury

Measuring method

– Dosing of the reagents into the sample vessel

– Mixing of the sample and mobilisation of the mercury

– Gas drying with subsequent detection of the released mercury by AAS

– Automatic rinsing step

– In the AFS system, additional intermediate focusing by amalgamation

Industries and branches

– Environment

– Food industry

Use and applications

Suitable for a wide range of digestions (e.g. aqua regia/microwave) of solid or liquid samples, as well as aqueous samples, including drinking water, groundwater, industrial wastewater, river, lake and sea water and rainwater.

Standard methods

The RA-4300A has conformity to the following methods, among others: DIN EN ISO 12846, DIN EN 1483, DIN ISO 16772, ISO 5666:1999, USEPA 245.1, USEPA 245.2, USEPA 245.5, USEPA 7470A, USEPA 7471B, ASTM D3223-02

Product details


– Method: Discrete mercury reduction after addition of the reagents in a batch process.

– Integrated autosampler with 80 positions incl. housing and exhaust system

– Integrated reagent dosing system for hydroxylamine hydrochloride, tin(II) chloride and sulphuric acid

– Detection: cold vapour atomic absorption spectroscopy / cold vapour atomic fluorescence spectroscopy

– Measuring range: 0.5 ppt to 100 ppb

– Analysis time: 2-4 min

– Gas supply: internal – no laboratory gases required

– Operating system for control software: Windows

– Dimensions: width – 58cm; depth: 53cm; height: 62cm

– Weight: 38Kg

Software and use

The RA-4300A is controlled by specific control software that allows intuitive use for easy and robust operation. Fast commissioning, simple set-up of measurement sequences including calibration, easily visualised results, standby functions, extensive reporting and numerous diagnostic as well as service tools characterise the software.

Figure 2: RA-4300A Software



The RA-4300 is also available as an AFS system for ultra-trace analysis. This system uses laboratory gas as the carrier gas and, in addition to enclosing the system, is equipped with a clean air filter to prevent contamination of samples by laboratory air.


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