Atomic Fluorescence Spectrometer for Mercury and Arsenic in Water

What is the Atomic Fluorescence Spectrometer for Mercury and Arsenic in Water?

A non-dispersive atomic fluorescence spectrometer with hydride generation and cold vapor modes, detecting mercury, arsenic, selenium, antimony, bismuth and tin in water at sub-µg/L levels. It is widely used for drinking water and surface water compliance testing in China.

Overview

This variant combines a continuous-flow or sequential-injection hydride generation system with a quartz atomizer, argon-hydrogen flame and non-dispersive optical path using a hollow cathode or high-intensity lamp. Sample and potassium borohydride in sodium hydroxide react with hydrochloric acid, releasing arsine, stibine or mercury vapor, which a gas–liquid separator delivers to the atomizer. Fluorescence is collected at right angles and measured by a solar-blind photomultiplier, reducing scattering interference. Detection limits are typically 0.01 µg/L for mercury and 0.05 µg/L for arsenic, with RSD below 2%. Dual-channel models read two elements simultaneously, and autosamplers handle 40 to 100 samples. Argon consumption is about 400 mL/min, and pre-reduction with thiourea and ascorbic acid converts arsenic(V) to arsenic(III). The technique is limited to hydride-forming elements, but its simple, inexpensive operation makes it a standard method under HJ 694 for water.

How does it work?

Heavy metal analyzers rely on electrochemical or atomic spectroscopic principles. In anodic stripping voltammetry (ASV), metals are first deposited onto a working electrode at a negative potential, then re-oxidized by a potential sweep, and the stripping current peak at a characteristic potential is proportional to concentration. In atomic absorption spectrometry (AAS), a sample is atomized in a flame or graphite furnace and a hollow cathode lamp beam is absorbed at the metal's wavelength according to Beer–Lambert law. Atomic fluorescence spectrometry (AFS) generates mercury or arsenic hydrides by reaction with borohydride, excites the atoms with a lamp and detects the emitted fluorescence at right angles. Calibration with certified standards, matrix modification and blank correction yield concentrations in µg/L.

What are the key features?

• Hydride generation and cold vapor modes for As, Se, Sb, Bi, Sn and Hg
• Dual-channel detection reads two elements simultaneously
• Solar-blind photomultiplier with non-dispersive right-angle optical path
• Autosampler with 40 to 100 positions and continuous-flow sample introduction
• Low argon consumption of about 400 mL/min
• Software with method templates for HJ 694 and GB 5749 elements

What are the technical specifications?

A typical atomic fluorescence spectrometer for mercury and arsenic in water configuration offers analytes of Hg, As, Se, Sb, Bi, Sn, Pb, Cd, Te, detection limit (Hg) of ≤ 0.01 µg/L, detection limit (As) of ≤ 0.05 µg/L, repeatability of RSD ≤ 2%, linearity of R ≥ 0.999 up to 100 µg/L and detector of Solar-blind photomultiplier. Values are indicative of the product class; the exact figures for each configuration are confirmed on the quotation and the calibration documents supplied with the instrument.

Which applications is it used for?

The Atomic Fluorescence Spectrometer for Mercury and Arsenic in Water is used in mercury and arsenic compliance in drinking water, surface water and groundwater arsenic surveys, selenium and antimony in wastewater and food and soil digest analysis for Hg and As. Across the wider Heavy Metal Analyzers class, laboratories also deploy it for drinking water lead, cadmium and arsenic compliance, industrial wastewater discharge metal monitoring and mercury and arsenic determination in surface water.

Which standards and certifications apply?

Relevant standards and methods include ISO 15586, ISO 17294-2, ISO 11885, ISO 17852, ISO 11969, HJ 694, HJ 700, GB/T 5750.6, ASTM D3559 and IEC 61010-1. Certification candidates for this model are CE and ISO 9001 manufacturing; each is to be confirmed for the specific configuration before shipment, and certificates are supplied only where they have been issued.

Trace metal work starts with contamination control: use acid-washed plastic containers, high-purity nitric acid and ultrapure water, and preserve samples to pH below 2. Digest samples containing particulates or organics according to the method before analysis. Calibrate with a blank and at least three standards and verify with independent check standards, spikes and duplicates each batch. AAS and AFS need compressed gases, exhaust ventilation and lamp warm-up, and mercury methods need gold-trap or cold-vapor handling. Electrodes for ASV need polishing or replacement of mercury-free film. Handle acid, mercury and arsenic waste under local hazardous waste rules. Use instruments in rooms with stable temperature and follow IEC 61010-1 safety requirements.

How do I select the right Atomic Fluorescence Spectrometer for Mercury and Arsenic in Water?

Select the AFS system when mercury, arsenic, selenium or antimony must be reported at sub-µg/L levels at modest cost, particularly under Chinese methods such as HJ 694. Choose AAS for a broader element list. In an RFQ, specify channels, autosampler capacity, argon supply, target elements, digestion system and reporting method.

How does it compare with other Heavy Metal Analyzers variants?

Match the technique to the metals, detection limits and workload. For lead, cadmium, copper and zinc screening at low cost, stripping voltammetry offers µg/L sensitivity and portability. Mercury, arsenic, selenium and antimony at sub-µg/L are best served by atomic fluorescence with hydride generation. Flame AAS handles mg/L to high µg/L levels of common metals such as copper, zinc, iron and chromium quickly and economically. Graphite furnace AAS reaches sub-µg/L for cadmium, lead and chromium with tiny sample volumes but at lower throughput. If you must analyze many elements simultaneously at ng/L levels, ICP-MS is a different class of instrument. Consider the regulatory limit, sample numbers, digestion needs, gases required, operator skill and whether results must follow a named method such as HJ 694 or ISO 15586.