Ngā Tikanga Hiko-whakairoiro i roto i te Matū Tātari
He tikanga matarohia engari he mea nui tonu te ine irahiko i roto i te matū tātari, inā koa mō te ine i ngā katote konganuku i roto i te otinga. Ka whakakotahihia e tēnei tikanga ngā mātāpono o te ine irahiko me te ine irahiko: ka whakatakotoria te tātari hei konganuku ki runga i te irahiko mā te ine irahiko, ā, ka paunatia te matū i puta mai hei tatau i te nui o te tātari. Nā te mea he ine papatipu te hua whakamutunga, e mōhiotia ana he pai te tika o te ine irahiko ina whakahaeretia tika ngā āhuatanga whakamātautau.
Whakamāramatanga me ngā Mātāpono Taketake
I roto i ngā kupu māmā noa iho, ko te electrogravimetry he tikanga tātari tauanga e whakatakotoria ai he momo (he cation whakarewa te tikanga) ki runga i te irahiko mā te iahiko hiko, kātahi ka whakamahia te pikinga o te papatipu o te irahiko hei whakatau i te nui o taua momo i roto i te tauira. Ko te nuinga o te wā ka hangaia te matūriki i te cathode mā te tauhohenga whakaiti:
Mⁿ⁺ + ne⁻ → M(s)
Ka piri te konganuku M kua hangaia ki te mata o te katote. Kia oti te hikohiko, ka horoia te hikohiko, ka whakamarokehia, ka whakamataohia ki roto i te whakamaroke, kātahi ka paunatia. Ko te rerekētanga o te papatipu i mua me muri i te hikohiko ko te papatipu o te konganuku kua whakatakotoria.
I tētahi atu taha, ko ngā tauhohenga waikura ka puta i te anode, pērā i te waikura o te wai hei whakaputa hāora. Me whiriwhiri te hanganga o te electrolyte tautoko, te pH, me te pūmanawa e whakamahia ana kia kaha ake ai te tauhohenga e hiahiatia ana, kia whakaitihia ai hoki ngā tauhohenga taha pērā i te whanaketanga hauwai i te cathode, ka taea ai te whakararu i te kounga o te putunga.
Ngā Wāhanga me ngā Taputapu
Kei roto i tētahi huinga whakamātautau hiko-whakamātautau noa:
1. Pūtake hiko: he pūtake hiko DC me te whakahaere iahiko (galvanostatic) he whakahaere pūmanawa rānei (potentiostatic).
2. Pūtau hikohiko: he ipu karāhe e pupuri ana i te otinga tauira me te hikohiko tautoko.
3. Irahiko mahi (katode): te wāhi e whakatakotoria ai te konganuku, he maha ngā wā ka whakamahia he pereti konukawata, he nikara, he irahiko motuhake rānei pērā i te "karāhe konukawata" hei whakanui ake i te horahanga o te mata.
4. Irahiko whakahē (anode): he koretake te nuinga (konukawata, karāpeti rānei) kia kore ai e memeha.
5. Pūnaha whakaoho: he whakaoho aukume, he whakaoho ā-ringa rānei hei whakatere i te whakawhiti papatipu (whakaiti i ngā herenga horapa).
6. Taurite tātari: he tino tika (tae atu ki te 0,1 mg, pai ake rānei) mō ngā irahiko pauna.
He mea tino nui te ma o te irahiko. Me kore he hinu, he waikura, he poke rānei i te mata o te irahiko kia piri ōrite ai ngā putunga me te ātete ki te pakarukaru.
Ngā Tikanga Whakahaere: Au Pūmau vs Pūmanawa Pūmau
E rua ngā huarahi matua e taea ai te whakahaere i te electrogravimetry:
1. Te Ine Irahiko Au Pūmau (Galvanostatic)
I tēnei tikanga, ka mau tonu te iahiko puta noa i te wā e whakamahia ana te hikohiko. Ko te painga ko te taputapu ngāwari noa iho. Heoi, i te hekenga o te kukū o te katote konganuku, ka taea e te pūmanawa katote te neke ki tētahi āhua kino ake, ka puta ai ngā tauhohenga taha (hei tauira, te whakahekenga o te H⁺ ki te H₂). Nō reira, ka taea e te putunga te taratara, te pūngāwerewere, te kore rānei e piri pai.
2. Te Ine Pūmanawa Pūmau (Potentiostatic)
I tēnei huarahi, ka whakahaerehia te pūmanawa hiko mahi i tētahi uara motuhake kia puta ko te tauhohenga analyte anake ka puta i runga i te kōwhiringa. He tino whai hua tēnei tikanga mō te wehewehe tīpakohia kia maha ngā konganuku i runga i ngā rerekētanga o te pūmanawa whakaiti. Ko te ngoikoretanga he uaua ake te taputapu (me whakamahi i te potentiostat) ā, ko te whakatau i ngā āhuatanga tino pai me mārama ake ki te matū hiko.
Ngā Wāhanga o te Tātaritanga Hiko-rahi
Ko te tukanga whānui o te electrogravimetry ko ngā mahi e whai ake nei:
1. Te whakarite i te hikohiko: ka horoia te hikohiko, ka whakamarokehia, ka whakamataohia ki roto i te whakamaroke, kātahi ka paunatia (papatipu tīmatanga).
2. Te whakarite otinga: ka whakarewaina te tauira, ka whakatikatikaina te pH, ā, ka tāpirihia ngā irahiko tautoko (hei tauira, H₂SO₄, HNO₃, tote kore mahi rānei) hei whakanui ake i te kawe hiko me te whakau i ngā āhuatanga.
3. Te hikohiko: ka tukuna he iahiko, he pūmanawa rānei i te wā e whakaohokia ana te otinga. Ka whakarerekētia te wā hikohiko kia tata kore rawa te katote ūnga e whakaitihia.
4. Te whakamātautau otinga o te ua: ka taea mā te tango i tētahi nui iti o te otinga me te tāpiri i tētahi matū hei whakarite kia kore he katote konganuku e toe ana, mā te tirotiro rānei i te hekenga o te iahiko ki te tata ki te kore i tētahi mana whakahaere.
5. Te horoi i te hikohiko: ka horoia te hikohiko ki te wai whakakore iona hei tango i te hikohiko e piri ana, kātahi ka horoia ki te waipiro, ki te whakarewa pūngāwerewere rānei hei tere ake te maroke.
6. Te whakamaroke me te pauna: ka whakamarokehia te hiko i te pāmahana e ai ki te momo putunga, ka whakamataohia ki roto i te whakamaroke, kātahi ka paunatia (papatipu whakamutunga).
7. Te tātai i te ihirangi: ka whakamahia te papatipu o te matū hei tātai i ngā mole o te konganuku me te kukū i roto i te tauira.
Ko te tātaitanga māmā rawa ko:
– te papatipu o te konganuku = te papatipu whakamutunga o te irahiko – te papatipu tīmatanga o te irahiko
– ngā mole o te konganuku = te papatipu o te konganuku / te papatipu o te konganuku
– te ihirangi = ngā mole, te papatipu rānei o te konganuku mō ia rōrahi tauira
Ngā Take e Pā Ana ki te Kounga o te Parapara
Ko te angitu o te ine hiko-rahi e whakawhirinaki ana ki te kounga o te matū i hangaia. Ko ētahi o ngā mea e whakatau ana ko:
– Te mātotoru o te iahiko: Ka hua ake he putunga matotoru, he rite ki te hautai i te nui rawa o te iahiko. Ka pōturi ake te tukanga i te iti rawa o te iahiko, ā, ka nui ake te tūponotanga o te poke.
– te pH me te hanganga irahiko: ka pā ki te whakarōpūtanga katote konganuku me te whakataetae tauhohenga (hei tauira, te whanaketanga hauwai).
– Te pāmahana: ka whakanui ake i te tere me te horapa o te tauhohenga, engari ka pā ki te pumau o te tauhohenga matū, ngā tauhohenga taha rānei.
– Te whakaoho: ka whakapai ake i te kawe papatipu kia ōrite ai te paru.
– Te noho mai o ngā matū whakauaua: ka taea e ētahi ligand te whakaiti i te kukū o ngā katote kore utu, ā, ka nekehia te pūmanawa taunga me te āwhina i te wehenga whiriwhiri.
Ko te whāinga matua he whakaputa i tētahi matūriki kiato, piri pūmau, ā, he parakore. Mēnā he matūriki e ngāwari te taka atu, e mau ana rānei ngā irahiko, ka pā kino ki ngā hua pauna.
Ngā Whakamahinga i roto i te Matū Tātari
He whānuitia te whakamahinga o te ine hiko mō te tātari i ngā konganuku pēnei i te Cu, Ni, Ag, Zn, Pb, Cd, me ētahi atu, i roto i ngā tauira ahumahi me te taiao. Ko ngā tono noa ko:
– Te whakatau i te nui o te parahi i roto i te otinga whakakikorua (kaukau whakakikorua hiko).
– Te tātaritanga o te nikara me te konupora i roto i ētahi koranu me ngā tautuhinga pea mō te wehenga.
– Te whakatau i te hiriwa i roto i ngā tauira whakaahua, i ngā para rānei kei roto ngā iona Ag⁺.
– Te tātari i ngā konganuku taumaha i roto i ngā otinga tātā i roto i ngā tukanga whakarewa.
Haunga te whakatau i te rahinga kotahi, ka taea hoki te whakamahi i te electrogravimetry hei taahiraa wehewehe i mua i te tātaritanga anō, hei tauira hei tango i ētahi pokanoa whakarewa kia pai ake ai te whiriwhiri i ngā inenga spectrophotometric, i te titration rānei.
Ngā Painga me ngā Here
Ngā painga o te ine hiko:
1. He tika, he pūmau hoki nā te mea he papatipu te ine.
2. Kāore e hiahiatia he paerewa titrant pērā i te titration.
3. Ka taea te whakatutuki i te whiriwhiringa teitei me te mana whakahaere pea.
4. He pai mō ngā kukū whakarewa āhua waenga ki te teitei.
Ngā herenga o te ine hiko:
1. Me whai wā hikohiko, ā, ka roa pea, inā koa i ngā taumata iti.
2. Ngāwari ki te pokanoa o te tauhohenga taha (hei tauira, te hauwai) me te poke o te paru.
3. Me whai pūkenga ki te whakarite i ngā irahiko me te whakahaere i ngā āhuatanga.
4. Kāore i te tino pai mō ngā tātaritanga kore-whakarewa, ngā momo rānei kāore e ngāwari te whakaputa mā te whakanoho hiko.
Whakamutunga
Ko te ine hiko he tikanga tātari tauanga e whakamahi ana i te maturuturunga hiko me te pauna papatipu hei whakatau i te ihirangi konganuku i roto i te tauira. Ahakoa he tikanga tawhito, he mea nui tonu te ine hiko i roto i te matū tātari nā te mea he tika, he mārama ngā mātāpono, me te kaha ki te wehewehe whiriwhiri me te whakahaere pūmanawa. Ko te angitu o tēnei tikanga ka whakatauhia nuitia e te whakahaere i ngā tawhā pēnei i te au/pūmanawa, te pH, te whakaoho, te pāmahana, me te ma o te irahiko. Mā te arotau tika, ka noho te ine hiko hei taputapu pono mō te tātari konganuku i roto i ngā momo mara, mai i te umanga whakakikorua ki te aroturuki konganuku taumaha.
Ki te hiahia koe, ka taea hoki e au te tāpiri i ngā tauira tātaitanga tau (hei tauira, te whakatau i te Cu²⁺) ka taea rānei e au te waihanga i tētahi putanga mātauranga ake o te tuhinga me ngā tohutoro me te rārangi pukapuka.
