IODP Expedition 400 Elemental analysis (CHNS)

Fundamental elemental component (total carbon, hydrogen, nitrogen, and sulfur) fluctuations help define the origin, depositional environment, and diagenetic alteration of source materials. To determine C, H, N, and S, solid samples are reacted with a catalyst, separated by chromatography, and detected by thermal conductivity on a FlashEA 1112 CHNS elemental analyzer. Organic carbon can be directly measured on the elemental analyzer by acidification of the sample to drive off carbonate as carbon dioxide before analyzing. Total organic carbon on this report is measured rather than calculated.基础元素组分（总碳、氢、氮与硫）的波动特征，可为明确物源的成因、沉积环境及成岩改造作用提供关键依据。为测定碳、氢、氮、硫元素含量，固体样品需先与催化剂反应，再经色谱分离，最后通过热导检测法在FlashEA 1112型CHNS元素分析仪上完成检测。有机碳可直接在该元素分析仪上测定：分析前先对样品进行酸化处理，使碳酸盐以二氧化碳形式逸出。本报告中的总有机碳均为实测值，而非计算所得。