In this paper, the entire publications on modern automation technique multisyringe flow injection analysis (MSFIA) of the last six years are conscientiously reviewed. MSFIA is compared to alternative flow techniques and multisyringe apparatus and its potentials are described in detail. The different injection modalities and manifold configurations as well as analytical applications according to the different detection techniques applied in MSFIA are described and compared. Features and potentials of the related analytical software AutoAnalysis are overviewed and explained on the background of automation examples. The characteristics and features of the analytical methods developed for MSFIA are summarized in a comprehensive overview table.
Owing to its widespread distribution in the environment, lead is attracting attention because of its high toxicity. Thus, relevant biological and environmental studies need the support of reliable procedures for the determination of lead at low concentrations. The present review is mainly concerned with the determination of lead in diverse environmental samples by flow injection analysis.
For the first time the sequential injection analysis technique was fully utilized for quantitative kinetic determination of Aspirin and comprehensive reaction rate measurement using permanganate as an oxidant in sulphuric acid media. The absorbance was monitored by the color decrease of permanganate absorbed at the wavelength 525 nm. The reaction orders with respect to Aspirin, permanganate and hydrogen ions were found to be positive one (+1), positive one (+1), and inverse one (-1) respectively. The Reaction mechanism was postulated and a fixed time kinetic method for quantitative analysis of Aspirin was adopted. A full kinetic study was executed resulted in postulating the mechanism of oxidation of Aspirin by permanganate for the validation of a newly adopted kinetic method for quantitative determination of the drug in pharmaceutical preparations. The fixed time kinetic method was applied and the following calibration equation A = -0.09980 + 0.00617 C with r = 0.999 was obtained at a the fixed time exactly 90 s with a flow rate of 25 μl/s. The linearity of the method was found to be ranged between 5 to 400 ppm for the analyte when injecting 30 μl of it and keeping constant concentrations and volumes of 30 μl 2.29 x10-3 mol l-1 potassium permanganate, 30 μl 0.05 mol l-1 sulphuric acid and 20 μl as spacer solution (water). The above calibration equation was employed for quantitative determination of Aspirin in drug formulations in different proprietary tablets. The results obtained proved accurate and precise for the assay of Aspirin in drug formulations without suffering interferences from other active ingredients and any of excipients usually added in tablet formulations.
A simple, rapid, selective and sensitive kinetic method for the determination of Paracetamol utilizing sequential injection analysis (SIA) technique was explored. The method was based upon comprehensive kinetic investigation of oxidation reaction of paracetamol with potassium permanganate in sulphuric acid media. The absorbance decrease of permanganate was measured at the wavelength 526 nm to monitor the reaction kinetics. The reaction orders with respect to the concentration of sulphuric acid, permanganate and paracetamol were found to be inverse one (-1), positive one (+1), and positive one (+1), respectively. The activation energy was examined and the reaction mechanism was postulated. The fixed time kinetic approach was used for the determination of the drug. The calibration equation "A = 0.0038C + 0.1209", with 0.9931 correlation coefficient (r) was found to be linear for paracetamol concentration ranging between 6.61 × 10-5 to 1.32 × 10-3 mol l-1 at the fixed time of 70 s at room temperature. This equation was obtained when injecting 35 μl of 1.0 mol l-1 H2SO4, 30 μl of 2.0 × 10-3 mol l-1 potassium permanganate, 20 μl of paracetamol and 25 μl water and by adjusting the flow rate at 25 μl s-1. The newly adopted method was applied for the determination of paracetamol in dosage forms of tablets and capsules containing other drugs. No interference was observed neither from the other drugs of diphenylamine hydrochloride, chloroxazone and pseudophedrine hydrochloride nor from excipients. The proposed SIA kinetic method was found to be accurate and repeatable when the results were statistically compared with the results obtained by the BP standard method.
A new simple flow injection kinetic spectrophotometric method has been developed for the determination of famotidine in pharmaceutical preparations. The method is based on a kinetic investigation of the oxydation reaction of the drug in alkaline potassium permanganate. The absorbance of the produced green coloured manganate species was monitored at 610 nm.
Flow injection variable parameters such as reagent concentration, injected volume, reactor length and flow rate were carefully investigated and optimised. The determination of famotidine in the range of 1-50 mg L-1 was possible with a correlation coefficient of 0.9981 and a detection limit of 0.22 mg L-1. The precision of the method was within 2% for 30 mg L-1 famotidine (n=5). The flow injection method can be satisfactorily applied to the determination of famotidine in pharmaceutical preparations with a sampling frequency of 60 samples h-1.
A spectrophotometric procedure based on flow injection analysis is proposed for Sb(III) and total Sb determination in pharmaceuticals. Sb(III) reacts with the hydrogen radical generated in the system, forming antimony hydride. The species formed is then transported towards the flow system and permeates through a Teflon® interface, being carried by a constant air flow. Then, a K2Cr2O7 solution in acidic medium is added by confluence, allowing the reduction of Cr(VI) to Cr(III) and the indirect determination of Sb at 610 nm. The proposed methodology presents a linear range from 200 to 1000 mg L-1 (r
> 0.997; n = 5), 70 mg L-1 as limit of quantification of and an analytical frequency of 40 h-1. The precision, expressed as RSD (n = 13 to 500 mg L-1 Sb(III) solution), is
< 5.0%. The accuracy for Sb(III) was checked through recovery tests and ranged from 96 to 105%. For total Sb, the accuracy was checked by atomic absorption spectrometry and the results are in agreement at the 95% confidence level, using the t test. Pharmaceutical samples were analyzed and an average value of 5.39 and 110 mg mL-1 for Sb(III) and total Sb concentrations, respectively, were obtained.