Introduction
A graphite digester is a laboratory instrument used for the digestion of samples, such as environmental, food, agricultural, and industrial samples, with acids, to prepare them for elemental analysis, and it is used in analytical chemistry, environmental testing, food safety, and many other laboratories. The digester consists of a heating block made of graphite, which has excellent thermal conductivity and uniform heating, with wells that hold the digestion tubes, a temperature controller, and, in many models, a fume extraction system; in operation, the sample is placed in a digestion tube with the digestion acid, such as nitric acid, and the tube is placed in the heated graphite block, which heats the sample and acid to the digestion temperature, typically 100-200 degrees Celsius, for a specified time, digesting the organic matter and dissolving the sample for analysis of metals and other elements; the uniform heating of the graphite block provides consistent digestion, and the digester is available with various numbers of wells, from a few to many, with features such as precise temperature control, programmable heating programs, and fume control. Graphite digesters are used for digesting soil, water, food, feed, plant, and other samples for the analysis of metals by atomic absorption spectrometry, inductively coupled plasma, and other techniques, for environmental monitoring, for food safety testing, for agricultural analysis, and for many other applications, and they are available as benchtop instruments. With their uniform and controlled digestion, graphite digesters are essential for sample preparation in elemental analysis.
Graphite Kjeldahl Digester LKGD-T2010
Graphite Kjeldahl Digester is an eco-friendly graphite digester system with anti-corrosive design comprised of high temperature infrared radiation heating technology. Features 20 digesti...
Graphite Block Kjeldahl Digester LKGD-T2011
Graphite Block Kjeldahl Digester is an eco-friendly graphite block digester system with anti-corrosive design comprised of high temperature infrared radiation heating technology. Feature...
Standards
ISO 1871:2009-Food and feed products-General guidelines for the determination of nitrogen by the Kjeldahl method
Complies with the above standards, but is not limited to them.
Features
1. Graphite digester for automated acid digestion of samples for elemental analysis.
2. Graphite block heating with precise temperature control for sample digestion.
3. Suitable for environmental, food, pharmaceutical, geological and research labs.
4. Includes graphite block, heating system, temperature controller, tubes and manual.
5. Supports automated sample digestion for AAS, ICP, ICP-MS and XRF analysis.
FAQ
Q1: What testing scenarios is this digester mainly applied to?
A: The graphite digester is used in environmental testing, food and beverage, pharmaceutical analysis, geological exploration, chemical research, agriculture and laboratories to perform automated acid digestion of solid, semi-solid and liquid samples using graphite block heating with precise temperature control for subsequent elemental analysis by AAS, ICP, ICP-MS and other techniques. It supports environmental sample digestion (soil, sediment, sludge, waste), food and beverage sample preparation (heavy metal analysis), pharmaceutical elemental impurity testing (ICH Q3D, USP <232>), geological sample digestion (rocks, minerals, ores), agricultural sample preparation (plants, fertilizers), and general laboratory sample digestion. The graphite block provides uniform, precise heating for consistent, reproducible digestion results, critical for accurate elemental analysis.
Q2: What standards does the digester comply with?
A: The graphite digester follows relevant ISO, ASTM and GB/T standards for sample preparation and digestion, including methods for heavy metal analysis in food (GB 5009), environmental samples, and pharmaceutical elemental impurities (USP <233>, ICH Q3D). The hardware complies with IEC 61010 laboratory safety standards. Temperature accuracy should be verified with a calibrated reference. Acid digestion follows applicable safety regulations for acid handling and fume extraction.
Q3: What is the warranty period for the whole machine and key components?
A: The whole graphite digester is covered by a 12-month warranty. The graphite block, heating system, temperature controller, housing and housing are covered, while digestion tubes, caps, acid-resistant coatings and fuses are consumables or accessories. Damage from improper use, acid spills, overheating or unauthorized repair is excluded. Extended service contracts are available for this sample preparation equipment.
Q4: Is this device difficult to operate? Is professional training required?
A: Operation requires trained laboratory personnel familiar with acid digestion, sample preparation and chemical safety. We provide operation manuals, training and application support. Proper sample weighing, acid selection and volume, temperature program setting, fume extraction, safety procedures and result interpretation are important for safe, effective digestion.
Q5: What is the typical lead-time for order delivery?
A: Standard models require 7-30 working days. In-stock units can ship within 3-7 working days. Custom configurations or large built-to-order systems may require additional time, and we confirm the exact schedule before order confirmation.
Q6: Is regular calibration required? What is the recommended calibration cycle?
A: Temperature calibration against a reference thermometer recommended every 6-12 months. Graphite block condition and uniformity verified periodically. Digestion tube condition checked. Routine cleaning of block and tubes. Full system performance verification annually with certified reference materials.
Q7: Are supporting consumables universal?
A: Digestion tubes, caps, acids, reference materials and cleaning supplies are available from laboratory suppliers, though tube type should match the block. Long-term consumable cost depends on sample volume and acid usage.
Q8: Can I customize parameters or supporting accessories?
A: Customization includes block capacity (number of tubes), tube size, temperature range, program memory, fume extraction, corrosion-resistant coating and accessories. Additional tubes, racks and accessories can be ordered separately. Custom orders extend delivery lead-time.
Q9: Does the purchase include on-site installation and commissioning service?
A: Standard delivery includes the graphite digester and accessories with an operation manual. On-site installation, calibration and training are not included for standard orders but can be arranged at additional cost. Remote guidance is provided. Fume hood or acid fume extraction is required for operation.
Q10: What types of samples are compatible with this equipment?
A: The graphite digester digests solid, semi-solid and liquid samples including soils, sediments, foods, pharmaceuticals, plants, geological materials and other matrices within the sample size, acid type and temperature specification. Different sample types require specific acid mixtures (nitric acid, hydrochloric acid, perchloric acid, hydrofluoric acid) and digestion programs. Users should select appropriate acid mixture for the sample matrix (e.g., nitric acid for general, nitric+hydrofluoric for siliceous materials), use proper sample size (typically 0.1-1 g), follow proper acid handling safety (fume hood, PPE), set appropriate temperature ramp and hold program, ensure proper fume extraction, allow cooling before opening tubes, dilute digests appropriately for analysis, and for regulated use, include method blanks and certified reference materials for quality control. The digester should be operated in a fume hood or with proper acid fume extraction due to corrosive acid fumes. Digestion tubes should be inspected for damage before use. The graphite block should be cleaned regularly to prevent acid corrosion and cross-contamination. For samples with high organic content, pre-digestion (overnight) may be required to prevent excessive foaming. Perchloric acid digestion requires special safety precautions (explosion risk with organic materials). Hydrofluoric acid requires special handling and plastic tubes (not glass). The digested samples should be properly stored and analyzed within recommended timeframes.
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