Construction and characterization of potentiometric sensor for the determination of oxytetracycline hydrochloride

Quantitative Analysis of Methacycline Hydrochloride by Direct Potentiometry Using the Internal Solid Contact Sensor

“…Previous experimental investigations 5,6 have found that the conditions/parameters of electropolymerization for pyrrole (or aniline) could affect the response performances of ISCSs to some extent.…”

“…The "a" and "b" used in present work are 1.5 and 30, respectively. 5,9 The largest CQI value gives the highest quality of the sensor, indicating the best polymerization parameter as well.…”

“…disc electrode used as the working electrode, SCE as reference electrode and platinum wire electrode as counter electrode, by repeating potential scan method, and of preparation of ISCS by dipping-coating procedures are the same as described by Sun et al 5,6 The following conditions are used for preparation of PPy or Pan film on substrate for a sensor. Evaluation of the comprehensive quality of sensor 5,9 The value of CQI for a given sensor is caculated using the following equation: CQI = ΣfiPi, where fi denotes a weighting factor whose values are 0.38 for f1, 0.30 for f2, 0.22 for f3 and 0.10 for f4, respectively, and Pi denotes the devoting of one of performances, which include S (mV/decade), LR (M), LD (M) and T (s) which is defined as the time needed for the sensor to reach a stable potential value after a concentration step from 10 -4 to 10 -3 M of the primary ion, 11 to the value of CQI, and the values can be calculated from the following formula: P1 = S/20, P2 = lg[LR]upper limit -lg[LR]lower limit, P3 = aLDmax/LDi, P4 = b/Ti. The "a" and "b" used in present work are 1.5 and 30, respectively.…”

“…5 A method for calculating the value of CQI is based on the procedure that each of the four experimental factors: slope (S), linear concentration range (LR), limit of detection (LD) and response time (T), of a electrode is quantitated to be one number (less than 1.2), according to a given formula and a weighting factor. This was documented to be efficient.…”

“…3,4 Therefore, searches for new analytical methods or techniques for the determination of tetracyclines in various samples have attracted a great deal of attentions. 2,5,6 For the determination of MC·Cl, some pharmacopoeias recommend high performance liquid chromatography (HPLC) 7,8 and antibiotics-microbial assay. 7 A few analytical methods including HPLC, spectrophotometry and phosphorimetry for the determination of MC·Cl in pharmaceutical analysis have been reported in the literature.…”