vial                            date           treatment               time_elapsed  Fe_II_concentration  standard_deviation  
PV-1_ASWkan_ferrozine_vial_1    2016/11/05     ASW 1                   72            0.002860456          0.001061685         
PV-1_ASWkan_ferrozine_vial_1    2016/11/06     ASW + kan 1             96            0.003993475          0.006916902         
PV-1_ASWkan_ferrozine_vial_1    2016/11/07     ASW + kan 1             120.5         below detection      nd                  
PV-1_ASWkan_ferrozine_vial_1    2016/11/08     ASW + kan 1             145.5         below detection      nd