Determination of Lactate by Sequential Injection Analysis Using a Fluoride Ion-selective Electrode Detector

A combination of sequential Injection Analysis (SIA) system and the ion-selective electrode (ISE) detector is considered to be one of a very effective analytical method. Reaction of lactate with lactate oxidase produces pyruvic acid and hydrogen peroxide. When the produced hydrogen peroxide is reacted with 4-aminoantipyrine (4-AAP) and 4-fluorophenol (4-FP) in the presence of horseradish peroxidase (HRP), F− ion is produced. The concentration of lactate can be indirectly determined by measuring the F− ion by F− ISE. Based on this principle of detection of lactate, a new measurement method of lactate using an SIA with ISE detector was developed

Sequential Injection Analysis of Butyrylcholinesterase Using Butyrylcholine Ion-Selective Electrode Detector

A new automated analytical method for the determination of Butyrylcholinesterase (BChE) based on sequential injection analysis (SIA) method using a butyrylcholine chloride (BuCh) ion-selective electrode (ISE) detector was developed. BuCh is degraded to choline and butyrate by the enzymatic activity of BChE, resulting in a decrease in BuCh concentration. By detecting this change in BuCh concentration with BuCh-ISE, BChE can be determined indirectly. In the present SIA method using the BuCh-ISE detector based on α-cyclodextrin membrane, BChE in the concentration range of 0.015–0.50 units/mL was determined at a BuCh concentration of 2.0 mmol dm−3 and a reaction time of 5.0 min. The detection limit for BChE is 4.8 × 10−3 units/mL

Determination of Polyhexamethylene Biguanide Hydrochloride Using a Lactone-Rhodamine B-Based Fluorescence Optode

A new determination method for polyhexamethylene biguanide hydrochloride (PHMB) using a lactone-rhodamine B (L-RB) based fluorescence optode has been developed. The optode membrane consists of 2-nitrophenyl octyl ether as a plasticizer, L-RB, and poly (vinyl chloride). The optode responds to tetrakis (4-fluorophenyl) borate, sodium salt (NaTPBF) in the μM range. The fluorescence intensity of the L-RB film for PHMB solution containing 20 μM NaTPBF decreased linearly as the concentration of the PHMB solution increased in the concentration range from 0 to 8.0 μM, which shows that PHMB with a concentration range of 0 to 8.0 μM is determined by the L-RB film optode. The concentration of PHMB in the contact lens detergents by the proposed method was in accord with its nominal concentration

Sequential Injection Analysis of Butyrylcholinesterase Using Butyrylcholine Ion-Selective Electrode Detector (Supporting Information)

A new automated analytical method for the determination of Butyrylcholinesterase (BChE) based on sequential injection analysis (SIA) method using a butyrylcholine chloride (BuCh) ion-selective electrode (ISE) detector was developed. BuCh is degraded to choline and butyrate by the enzymatic activity of BChE, resulting in a decrease in BuCh concentration. By detecting this change in BuCh concentration with BuCh-ISE, BChE can be determined indirectly. In the present SIA method using the BuCh-ISE detector based on α-cyclodextrin membrane, BChE in the concentration range of 0.015–0.50 units/mL was determined at a BuCh concentration of 2.0 mmol dm−3 and a reaction time of 5.0 min. The detection limit for BChE is 4.8 × 10−3 units/mL.</p