vial                            date           treatment               time_elapsed  Fe_II_concentration  standard_deviation  
PV-1_ASWkan_ferrozine_vial_3    2016/11/05     ASW 3                   72            0.00249081           0.002248393         
PV-1_ASWkan_ferrozine_vial_3    2016/11/06     ASW + kan 3             96            below detection      nd                  
PV-1_ASWkan_ferrozine_vial_3    2016/11/07     ASW + kan 3             120.5         below detection      nd                  
PV-1_ASWkan_ferrozine_vial_3    2016/11/08     ASW + kan 3             145.5         below detection      nd