3ND4|1|A|K|18 K ion 3ND4|1|A|K|18||||4_555 K ion 3ND4|1|A|MG|17 MG ion 3ND4|1|A|MG|17||||4_555 MG ion 3ND4|1|A|NA|19 NA ion 3ND4|1|A|NA|19||||4_555 NA ion