Preparation for nitrocellulose membrane-poly (vinyl alcohol)-ionic imprinting and its application to determine trace copper by room temperature phosphorimetry.
Nitrocellulose membrane-poly (vinyl alcohol)-ionic imprinting (NCM-PVA-I-I) was prepared using Cu2+ as template. The cavity in NCM-PVA-I-I matched Cu2+ very well and the selectivity was high. Cu2+ entered the cavity and then could form ionic association ([Cu2+] x [(Fin-)2]) with the anion of fluorescein (Fin-) outside the cavity by electrostatic effect. [Cu2+] x [(Fin-)2] could emit strong and stable room temperature phosphorescence on NCM-PVA-I-I. Its DeltaI(p) was proportional to the content of Cu2+. Based on the above facts, a new method for the determination of trace copper by solid substrate-room temperature phosphorimetry (NCM-PVA-I-I-SS-RTP, SS-RTP is the abbreviation of solid substrate-room temperature phosphorimetry) using NCM-PVA-I-I technique has been established. The linear range of this method was 2.00-144.00 fg Cu2+ spot(-1) (sample volume: 0.40 microL spot(-1), corresponding concentration: 5.00-360.00 pg mL(-1)), and the detection limit calculated by 3Sb/k was 0.43 fg Cu2+ spot(-1) (corresponding concentration: 1.1 x 10(-12) g mL(-1), n=11). Samples containing 2.00 and 144.00 fg Cu2+spot(-1) were measured, respectively, for seven times and R.S.D.s were 3.5% and 4.7%. NCM-PVA-I-I-SS-RTP could combine very well the characteristics of both the high sensitivity of SS-RTP and the high match and selectivity of NCM-PVA-I-I, and it was rapid, accurate, sensitive and with good repeatability. It has been successfully applied to determine trace copper in human hair and tea samples.
Li
Zhi-Ming
ZM
Department of Food and Biological Engineering, Zhangzhou Institute of Technology, Zhangzhou 363000, PR China.
Liu
Jia-Ming
JM
Liu
Zhen-Bo
ZB
Liu
Qin-Ying
QY
Lin
Xuan
X
Li
Fei-Ming
FM
Yang
Min-Lan
ML
Zhu
Guo-Hui
GH
Huang
Xiao-Mei
XM
D003101:Collodion / Q000737:chemistry*; D003300:Copper / Q000032:analysis*; D007477:Ions; D011142:Polyvinyl Alcohol / Q000737:chemistry*; D013696:Temperature
D007477:Ions; D003300:Copper; D011142:Polyvinyl Alcohol; D003101:Collodion