Kjeldahl Tablets Description
Kjeldahl Tablets consist of
compressed inorganic catalysts designed to optimize the sulfuric acid digestion
of organic nitrogen into ammonium sulfate. The Wieninger formulation—comprising
sodium sulfate (96.5%), copper sulfate (1.5%), and selenium (2.0%)—exhibits a
distinctive gray appearance due to raw material interactions, though this does
not impede functionality. Each tablet dissolves fully at 200 g/L in water,
yielding a solution with pH 5.0 at 20°C. The inclusion of selenium enhances
oxidation efficiency, while copper sulfate stabilizes reaction kinetics.
Tablets exhibit indefinite ambient storage stability (no temperature
restrictions) but carry environmental hazards (WGK 3, Aquatic Chronic 3) due to
selenium's chronic toxicity to aquatic life. Mercury-free variants (e.g.,
1.18348.0250) replace selenium with titanium-based accelerators for
eco-sensitive workflows.
Kjeldahl Tablets Applications
Protein Quantification: Primary
catalyst for nitrogen digestion in meat, dairy, and grain products per AOAC
981.10 and ISO 20483.
Feed Analysis: Determines crude
protein content in animal feeds using Buchi KjelDigester systems.
Fertilizer Testing: Measures
nitrogen availability in soil and fertilizer samples.
Environmental Monitoring: Analyzes
nitrogen pollution in wastewater and compost.
Kjeldahl Tablets Packaging
Our products are packaged in customized cartons of various
sizes based on the material dimensions. Small items are securely packed in PP
boxes, while larger items are placed in custom wooden crates. We ensure strict
adherence to packaging customization and the use of appropriate cushioning
materials to provide optimal protection during transportation.
Packaging: Carton, Wooden Box, or Customized.
Kindly review the packaging
details provided for your reference.
Manufacturing Process
1. Testing Method
(1) Chemical Composition Analysis: Verified using techniques
such as GDMS or XRF to ensure compliance with purity requirements.
(2) Mechanical Properties Testing: Includes tensile strength,
yield strength, and elongation tests to assess material performance.
(3) Dimensional Inspection: Measures thickness, width, and
length to ensure adherence to specified tolerances.
(4) Surface Quality Inspection: Checks for defects such as
scratches, cracks, or inclusions through visual and ultrasonic examination.
(5) Hardness Testing: Determines material hardness to confirm
uniformity and mechanical reliability.
Please refer to the SAM testing procedures for detailed information.
Kjeldahl Tablets FAQs
Q1. What distinguishes Wieninger from Missouri catalyst
formulations?
Wieninger tablets (e.g., Merck 1.17958) contain a fixed
ratio of sodium sulfate (96.5%), copper sulfate (1.5%), and selenium (2.0%),
whereas Missouri variants (e.g., Supelco 4058653) use potassium sulfate and
reduced copper (0.3–1.8%) without selenium. Wieninger offers faster digestion
but higher aquatic toxicity; Missouri is safer for environmental labs.
Q2. Why does my dissolved tablet solution appear cloudy?
Cloudiness indicates interaction with hard water impurities
(Ca²⁺/Mg²⁺). Always use deionized water (resistivity >1 MΩ·cm). Filter
through 0.45 μm if cloudiness persists.
Q3. Can these tablets replace liquid catalysts in
Kjeldahl digestion?
Yes, one 5g tablet typically replaces 7–10 mL liquid
catalyst, reducing acid consumption by 15% and digestion time by 30%.
Related Information
1. Common Preparation Methods
Kjeldahl Tablets are manufactured
via direct compression of reagent-grade sodium sulfate, copper sulfate, and
selenium powder. Raw materials are micronized to <50 μm particle size,
dry-blended in high-shear mixers for homogeneity, and compressed at 10–15 kN
force into tablets of defined weight (3.5 g or 5 g). Mercury-free variants
substitute selenium with titanium dioxide or potassium sulfate.
Post-compression, tablets are coated with anti-caking agents and packaged in
moisture-resistant containers with desiccants. Quality control includes
disintegration testing (<2 minutes), catalyst uniformity verification (XRF
analysis), and heavy metal screening (Pb ≤0.1 ppm).
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