高频燃烧-红外分析仪测定海洋沉积物的总碳含量

Determination of Total Carbon in Marine Sediments by High Frequency Combustion-Infrared Analyzer

应用高频红外分析仪测定海洋沉积物的总碳含量。于坩埚中预置纯铁屑0.2g,准确称取沉积物样品50.0mg置于坩埚中,再加入纯铁屑0.2g,使其与样品充分混匀,再加入钨粒1.6g,使其均匀覆盖在样品上面。加入的铁屑与钨粒起了助熔剂的作用。以下按仪器工作条件进行通氧燃烧和测定。按所提出的分析条件测定了两种标准物质(GBW07364和GBW07366)中的总碳量,测定结果与认定值相符,测定值的相对标准偏差(n=10)分别为2.3%,1.8%。该方法的检出限(3s)为0.0004%。应用此方法测定了18种海洋沉积物样品中的总碳量,并用元素分析仪对这些样品进行了校对试验,结果表明两方法的测定结果基本相符。

High-frequency combustion infrared analyzer was applied to the determination of total carbon in samples of marine sediments. 50.0 mg of the sediment sample was placed onto 0.2 g of pure iron dust which was added to the combustion crucible prelimarily, and another portion of 0.2 g of pure iron dust was added and wellmixed with the sample. Then 1.6 g of tungsten grains were added to cover on the surface of the sample. Iron dust and tungsten grains were added as flux to promote fusion of sample. The crucible with sample and flux was placed into the analyzer and the determination was carried out through combustion and inspection as described in the working conditions of the instrument. Total carbon in 2 CRMs of GBW 07364 and GBW 07366 were determined by the prescribed procedure, giving results in consistency with the certified values, and RSDs (n = 10) found for the 2 CRMs were 2.3% and 1.8% respectively. Detection limit (3s) found were 0. 000 4%. 18 samples of marine sediments were analyzed for total carbon by the proposed method , giving results in consistency with the results found by the Vario EL element analyzer.