Thermo Scientific Delta V mass spectrometer with a dual inlet and Conflo IV interface connected to a Costech 4010 elemental analyzer (EA), and a high-temperature conversion elemental analyzer (TCEA). This instrument is the workhorse of UNM–CSI and is capable of measuring δ13C, δ15N, δ18O, and δ2H values of bulk organic substrates such as plant and animal tissues.