University of North Florida
Browse the Citations

Contact Info

Stuart Chalk, Ph.D.
Department of Chemistry
University of North Florida
Phone: 1-904-620-1938
Fax: 1-904-620-3535
Website: @unf

View Stuart Chalk's profile on LinkedIn


Classification: Pharmaceutical -> ampoule

Citations 4

"Determination Of Sodium Nitroprusside By Flow Injection With Spectrophotometric Detection"
Anal. Lett. 1995 Volume 28, Issue 2 Pages 295-306
Alwarthan, A.A.

Abstract: Samples (150 µL) were injected into a carrier stream (0.72 ml/min) of 0.15 M NaOH which merged with a stream (0.72 ml/min) of 5 mM sulfadiazine in 0.5 M HCl before passing to a reaction coil (150 cm x 0.8 mm i.d.) maintained at 70°C, where nitrite ions liberated from sodium nitroprusside (I) were diazotized. After merging with a stream (0.72 ml/min) of 0.1 mM N-(1-naphthyl)ethylene-diamine dihydrochloride in 0.5 M HCl, the solution passed through a second reaction coil (100 cm x 0.8 mm i.d.) where coupling occurred and the absorbance of the resulting purple azo dye was measured at 545 nm. Beer's law was obeyed from 0.1-100 µg/ml of I and the detection limit was 0.05 µg/ml. The RSD at 10 µg/ml I was 1.78%. Sample throughput was 17.5/h. Glucose and riboflavin interfered. The method was applied to a pharmaceutical preparation. Ampoule contents (50 mg I were dissolved in and diluted to 250 mL with 0.15 M NaOH; the recoveries were 99.5-100.25%.
Nitroprusside Spectrophotometry Heated reaction Interferences

"Flow Injection Spectrophotometric Determination Of Piroxicam"
J. Pharm. Biomed. Anal. 1993 Volume 11, Issue 10 Pages 933-938
C. Sánchez-Pedreño*, M. S. Garcia, M. I. Albero and J. Rodriguez

Abstract: Methanolic sample solution was injected into a carrier stream of methanol (1.2 ml/min) which merged with a stream of methanolic 0.1 M HCl and passed through a reaction coil (70 cm long) before detection at 332 nm. Alternatively, the carrier stream merged with a stream of methanolic 5 mM Fe(III); in this instance, detection was at 520 nm. Calibration graphs were linear for 0.15-15 and 30-500 µg/ml of piroxicam with use of detection at 332 and 520 nm, respectively; corresponding detection limits were 0.15 and 7.5 µg/ml. Recoveries were >98% for the two methods, and sample throughput was 90/h. The method was used to analyze suppositories, tablets, capsules, creams and ampoules. Two flow injection analysis (FIA) methods are proposed for the determination of piroxicam. The first involves measurement of the UV absorbance of a solution containing the drug, methanol and hydrochloric acid at 332 nm; in the second method a Fe(III)-piroxicam complex is formed in a methanolic medium and the absorbance is measured at 520 nm. In both methods, the peak height is used as a quantitative parameter and piroxicam is determined over the ranges 0.5-15 and 30-500 µg mL-1, respectively. The methods have been applied to the routine determination of the drug in dosage forms.
Piroxicam Spectrophotometry Complexation

"Determination Of Papaverine And Cocaine By Use Of A Precipitation System Coupled Online To An Atomic Absorption Spectrometer"
J. Pharm. Biomed. Anal. 1994 Volume 12, Issue 2 Pages 179-184
Marcelina Eisman, Mercedes Gallego and Miguel Varcarcel*

Abstract: In the reversed flow injection system (diagram given) incorporating an AAS instrument operated at 357.9 nm, portions (30 µL) of the precipitating reagent, aqueous 0.2% (for papaverine; I) or 0.25% (for cocaine; II) Reinecke's salt of pH 5, was injected into a stream (3.3 ml/min) of 10 mM HCl and passed through a reaction coil (130 cm x 0.5 mm i.d.) producing a high Cr peak. Samples of I or II in 10 mM HCl were then continuously pumped into the system and another injection of Reinecke's salt produced a precipitate which was retained on the filter producing a low peak. The difference between the two peaks represented the amount of precipitated Cr (proportional to the drug concentration). The calibration graphs were linear from 5-85 µg/ml of I and 50-850 µg/ml of II; the corresponding detection limits were 2 and 25 µg/ml and the corresponding RSD were 1.3% and 3.2%. Sample throughput was 150/h. Tolerated amounts of foreign drugs are tabulated. The method was applied to powdered tablets (0.4 or 3 g), oral drops (0.8 ml), syrup (20 ml) and an ampoule of injectable solution dissolved in 100 or 250 mL of H2O.
Papaverine hydrochloride Drugs Spectrophotometry Precipitation Reverse

"Determination Of Analgin By Flow Injection Analysis With Coulometric Detection"
Izv. Khim. 1991 Volume 24, Issue 1 Pages 118-123
Dakashev, A.D.;Ilcheva, L.I.;Dzambazova, P.

Abstract: Aqueous sample solution was introduced into a stream (0.3 mL min-1) of 0.1 M HCl with a rotation injection valve. In a potentiostatic coulometric detector dipyrone (I) was oxidized on a porous Pt electrode at 0.75 V vs. SCE. ). The method was applied in the analysis of bulk drugs as well as ampoulles and tablets. Recovery was 94.0 to 103.4% of I.
Analgin Coulometry Electrode Electrode