Automated Hydride Generation AAS with Autosampler

What is the Automated Hydride Generation AAS with Autosampler?

An automated hydride generation AAS uses an autosampler to prepare and deliver samples and reagents in sequence. It is chosen for routine, high-volume arsenic and mercury testing with full traceability and minimal operator input.

Overview

This system automates the sequence from sample pickup through reagent addition, reaction and measurement. The autosampler draws sample and optional prereaction reagents such as thiourea or ascorbic acid, then the manifold mixes them with acid and borohydride before the gas-liquid separator. Software holds the calibration, QC and sample order and can apply dilution, standard addition and automatic reanalysis. Because reagent volumes and timing are constant, precision improves over manual operation and operator exposure to acid and reductant is reduced. Vial capacity of 60 to 180 positions supports overnight runs. Warnings for low gas pressure, low reagent or failed QC pause the sequence, and results are logged against sample identities. The configuration is common in food safety, environmental monitoring and contract laboratories.

How does it work?

The sample is mixed with acid and sodium borohydride, which reduces the analyte to a volatile covalent hydride such as arsine or selenide. A carrier gas sweeps the hydride into a heated quartz tube or a small flame, where it decomposes into free atoms. The atoms absorb light from an element-specific hollow-cathode lamp, and absorbance follows the Beer-Lambert law. Because the hydride is separated from the liquid matrix before atomization, most interferents remain behind, which gives high sensitivity and low background. Mercury can be determined by cold vapor generation without heating because it is already volatile. Reaction conditions such as acid type and concentration, borohydride concentration, flow rates and reaction temperature must be tightly controlled, and interfering ions such as copper and nickel are masked or removed. Calibration uses aqueous standards treated in the same way as samples.

What are the key features?

• Autosampler with 60 to 180 vial positions
• Automated prereaction reagent addition
• Constant reagent volumes and timing
• Software calibration, QC and reanalysis rules
• Reduced operator contact with acid and reductant
• Overnight unattended operation

What are the technical specifications?

A typical automated hydride generation aas with autosampler configuration offers autosampler positions of 60–180 vials, elements of As, Se, Sb, Bi, Sn, Hg, detection limit of 0.05–0.5 µg/L, prereaction reagents of thiourea, ascorbic acid, carrier gas of argon, 200–400 mL/min and quartz cell temperature of 800–900 °C. 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 Automated Hydride Generation AAS with Autosampler is used in high-volume arsenic testing in drinking water, food safety programs for arsenic and mercury, environmental monitoring of soils and sediments and contract trace element analysis. Across the wider Hydride Generation AAS class, laboratories also deploy it for arsenic and selenium in drinking water, arsenic and mercury in rice, fish and seafood and antimony and tin in packaging material migration.

Which standards and certifications apply?

Relevant standards and methods include Ph. Eur. 2.2.22 Atomic absorption spectrometry, USP <852> Atomic Absorption Spectroscopy, ISO 11969 Water quality — Determination of arsenic by AAS, US EPA Method 7062 Arsenic by hydride generation, US EPA Method 7473 Mercury in solids and solutions and IEC 61010-1. Certification candidates for this model are CE, ISO 9001 manufacturing and 21 CFR Part 11 software compliance; each is to be confirmed for the specific configuration before shipment, and certificates are supplied only where they have been issued.

Hydride generation uses sodium borohydride solutions that must be prepared fresh or kept cooled, and reactions can release hydrogen gas, so ventilation is required. Acid and reductant concentrations, tubing lengths and gas flows affect the yield and must be fixed in the method. Interfering elements are controlled with masking agents such as thiourea or by separation. Quartz cells cloud with use and need periodic cleaning or replacement, and their temperature affects atomization efficiency. Because the technique measures a transient or steady signal from a gas, blank contamination from reagents is a common problem; ultrapure reagents and method blanks are essential. Install the system on the flame or furnace instrument with the correct gas supply and waste handling.

How do I select the right Automated Hydride Generation AAS with Autosampler?

Select the automated variant when sample numbers are high and reproducibility, traceability and operator safety are priorities. Specify the elements, throughput, vial capacity and whether prereaction reagents such as thiourea are needed. Confirm the software supports QC rules and audit trails required by your quality system.

How does it compare with other Hydride Generation AAS variants?

Choose a hydride generation system when the target elements are arsenic, selenium, antimony, bismuth, tin, tellurium or mercury and detection limits around 0.01 to 0.5 micrograms per litre are required at moderate cost. Continuous-flow designs offer stable signals and good throughput, flow-injection designs use less reagent and allow fast transient measurements, and batch systems are cheapest but slowest. If mercury is also required, add a cold vapor module or select an instrument with both modes. Multi-element configurations reduce time when several hydride-forming elements are measured together. For very low detection limits on arsenic and selenium, compare with ICP-MS, which may offer lower limits at higher cost.