thu o-phenantrolin
Khu toan bd Fe-^"" -> Fe""" bang hydroxylamin (NH.OH) trong mdi
4-^5 (dem axetat).
Do dp hap thu (D^) cua phúc mau tren may so mau quang dien d budc
sdng Ạ=510nm, cuvet = 4cm. So sanh Dy^ vdi đ thi chuan suy ra %Fe nhu
tren.
IV.2.L4. Phucmg phdp cue pho
Nghien cuu va su dung cac dudng đng the nham phuc vu cho viec nghien curu cac qua trinh dien cUc va phan tfch ham luemg mdt sd ion. De
thu dupe cac dudng đng the ngUcVi ta lien hanh dien phan, cd dien c\lc so
sanh.
Chieu cae) sêng cue pho ty le vé^i nong dp chat dien phan:
h =K . e
K : he sd dinh lucmg cue pho ^ nong dp chat dien phan
Hien nay cc') nhieu may hien dai lap san cac chuemg trinh. Khi mau can
do dxioc chuan bi theo chi dan, dua vao may cho ket qua ngaỵ
IV.2.2. Xdc dinh ion Al'^ [15, 17]
IV.2.L2. Phuong phdp chudn do phuc chdt
Cho du mdt the tfch chfnh xac dung dich Trilên B chuan vao mau can
xac dinh. Dem nung ndng khoang 1^2 (ph) luc do xay ra phan irng giiia
/.V^ va thudc thu:
A l " + H,Y=- p p ^ AIY- + 2H-
Dijng axetat kem tieu chuan de chuan luemg dụ Trih^n B. Diem tuemg
duemg cua phep chuan do dupe nhan biet bang chi thi xylenol da cam (edng
thuc kf hieu H,I,^d').
\ au^ Hong tim
Hoac dijn^ Fe-^"*" chuan lai lucmc du Trilon B chuan vcji chi thi H-,SSal.
g/lAl =
m^ịAl .(NV)BUT..-(NX'),.:,Pe3-jv„
V V .1000
LV.2.2.2. Xdc dinh bdng phuong phdp do quang - DiJng thudc thu Aluminon.
- Xay dung dudng chuan. - Do mat dp quang (Dv;).
- Dua vao dudng chuan tim %AỊ
IV.3. X a c dinh canxi trong d u n g dich nirdc
Theo tac gia cdng trinh [6] trong mdi tmcmg kiem manh (pH=12) iên Ca""*" tao veti murexit mot phuc chat mau tfm dọ Phuc nay kem ben hem phuc Cã"^ vcti Trilon B. Vi vay khi chuan do Ca""*" bang dung dich chuan Trilon B vdi chi thi murexit, tai diem cucVi ciia phc^p chuan do se xay ra sir chuyen mau:
Car +H3Y-- = MeY-- +2H^ + T
Dd da cam Tim