Metrohm presents the 909 UV Digester, a new digestion unit for sample preparation by UV photolysis. The 909 UV Digester enables simultaneous digestion of up to 12 samples and excels by its robust design and short digestions times. It is recommeded for voltammetric and spectroscopic methods, where organic matter present in the sample interferes with the determination of the the heavy metal analytes.
Digestion of samples in the 909 UV Digester is fully automatic. The centerpiece of the digester is a UV lamp that provides the necessary UV radiation. The heat generated by the lamp is dissipated via an air-cooling system. To ensure that digestion takes place under controlled conditions, a Pt1000 temperature sensor is used to measure the digestion temperature in a reference sample. An integral microprocessor controls the digestion temperature and the digestion time.
Standards that recommend sample preparation by UV photolysis include:
- DIN 38406, Part 16: Determination of zinc, cadmium, lead, copper, thallium, nickel, cobalt by voltammetry
- DIN 38406, Part 17: Determination of uranium – Method using adsorptive stripping voltammetry in surface water, raw water and drinking water
UV digestion is suitable for transparent samples with low-to-medium organic contamination (up to approx. 100 mg carbon/L). The classical application field for UV digestion is processing of all types of water samples, e.g. surface waters or wastewaters. However, liquid biological samples (e.g. urine) or foods (e.g. juices and alcoholic beverages) too can be digested using an adapted procedure.