Solid Sample TOC Analyzer for Soils and Sediments

What is the Solid Sample TOC Analyzer for Soils and Sediments?

A solid sample TOC analyzer heats soils, sediments, sludge, and powders at 900 °C in oxygen and measures released CO2 by NDIR. It determines total carbon, and organic carbon after acid pretreatment or with staged heating, for soil and material characterization.

Overview

The solid sample TOC analyzer combines an NDIR detector with a dedicated furnace module and sample boat. A dried, milled sample of 50 mg to 1 g is weighed into a ceramic or quartz boat and pushed into a 900–1000 °C oxidation zone with oxygen. For organic carbon, carbonates are removed by pre-treatment with hydrochloric acid in silver capsules, or by staged analysis in which the TOC fraction burns at 400–600 °C and inorganic carbon is released at 900 °C. The method allows measuring TOC, TIC, and TC on the same platform and is commonly used with a liquid TOC module sharing the same detector. Measurement range is about 0.1 mg to 100 mg carbon absolute. Because soil samples are heterogeneous, homogenization by drying at 40–105 °C and milling to below 250 µm is critical for reproducibility.

How does it work?

A TOC analyzer separates carbon into inorganic carbon (carbonate and bicarbonate) and organic carbon. In the NPOC method, the sample is acidified to pH below 2 with hydrochloric or phosphoric acid and sparged with carrier gas so inorganic carbon leaves as CO2, then the remaining organic carbon is oxidized. High-temperature catalytic combustion injects the sample into a furnace at 680–1200 °C with a platinum or cobalt catalyst, converting organic carbon to CO2. Wet chemical oxidation uses persulfate and ultraviolet light to generate hydroxyl radicals at lower temperatures. The resulting CO2 is dried, halogens are scrubbed, and the gas passes through an NDIR cell at about 4.26 µm. Peak area is proportional to carbon mass and is calibrated with potassium hydrogen phthalate. Total nitrogen bound can be measured by chemiluminescence after combustion.

What are the key features?

• Furnace module operates at 900–1000 °C for complete oxidation of solid matrices.
• Determines TC, TOC, and TIC by acid pretreatment or temperature-staged analysis.
• Shares the NDIR detector with a liquid TOC module for flexible use.
• Ceramic boats and autosampler handle 50 mg to 1 g sample masses.
• Software calculates carbon content as mass percent with moisture correction.

What are the technical specifications?

A typical solid sample toc analyzer for soils and sediments configuration offers carbon range of 0.1–100 mg absolute, sample mass of 50 mg–1 g, furnace temperature of 900–1000 °C (staged 400–900 °C), acid pretreatment of Hydrochloric acid in silver capsule or boat, repeatability (CV) of ≤3% for homogenized soil reference and analysis time of 4–8 min per sample. 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 Solid Sample TOC Analyzer for Soils and Sediments is used in soil organic carbon and carbon sequestration studies, sediment and sludge characterization, geological and mineral carbon analysis and composite and battery material carbon content. Across the wider TOC Analyzers class, laboratories also deploy it for drinking water and surface water monitoring, wastewater and effluent compliance testing and soil and sediment organic carbon analysis.

Which standards and certifications apply?

Relevant standards and methods include ISO 8245, EN 1484, ASTM D7573, ASTM D4129, USP <643>, Ph. Eur. 2.2.44, ISO 10694 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.

Use carbon-free glassware or pre-baked vials and keep samples acidified and refrigerated if not analyzed immediately, because volatile organics are lost and microbial activity changes carbon. Ultra-pure carrier gas and low-blank water for calibration standards are essential at low ppb levels. Replace the combustion catalyst, halogen scrubber, and humidity trap based on sample load, and check the furnace tube for salt build-up with high-salt samples. Verify linearity with potassium hydrogen phthalate and check inorganic carbon recovery with sodium carbonate. System suitability in pharmaceutical use is performed with sucrose and 1,4-benzoquinone standards. Maintain calibration records and blank logs, and ensure ventilation for exhaust gas and acid fumes.

How do I select the right Solid Sample TOC Analyzer for Soils and Sediments?

Select the solid sample TOC analyzer when matrices are soils, sediments, sludge, or powders and no separate solids instrument is available. For high-volume metals or cement, a carbon sulfur analyzer is more appropriate. Specify sample mass, TOC method (acid or staged), boat autosampler capacity, and standards such as ISO 10694.

How does it compare with other TOC Analyzers variants?

The main selection criterion is the oxidation technique. High-temperature catalytic combustion handles particulate-laden, high-salt, and difficult organics, and covers ranges from 4 µg/L to 30,000 mg/L with suitable catalyst and injection volumes. UV-persulfate oxidation suits clean waters such as ultrapure and pharmaceutical water, with detection limits near 0.5 µg/L. Decide whether total nitrogen is needed and whether solid samples such as soils, sediments, or powders must be analyzed, because that requires a solid sample module with a furnace up to 900–1000 °C. Online process analyzers need continuous sampling, automatic calibration, and relay outputs. Consider autosampler capacity of 30–90 vials, sample volume, and the acid and catalyst consumption. Verify compliance with EN 1484, ISO 8245, and USP <643> when applicable.