IODP Expedition 393 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）的波动规律，有助于界定物源的成因、沉积环境及成岩蚀变特征。为测定碳、氢、氮、硫含量，需将固体样品与催化剂反应，经色谱分离后，通过热导检测法在FlashEA 1112型CHNS元素分析仪上完成检测。可在分析前通过酸化样品使碳酸盐以二氧化碳形式脱除，随后在该元素分析仪上直接测定有机碳含量。本报告中的总有机碳均为实测值，而非计算值。