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1.
Spectrophotometric Determination of Prochlorperazine Maleate in Pure and Pharmaceutical Preparations
Tehseen Aman Zeeshan Majeed Asrar Ahmad Kazi Islam Ullah Khan 《Mikrochimica acta》2002,138(1-2):13-17
Prochlorperazine maleate reacts with 1-naphthylamine and sodium nitrite, after heating for 110 s at 80 °C to give an orange
red colour having maximum absorbance at 460 nm. The reaction is selective for prochlorperazine maleate with 0.01 mg/mL as
visual limit of quantitation and provides a basis for a new spectrophotometric determination. The colour reaction obeys Beer’s
law from 0.01 mg/10 mL to 0.33 mg/10 mL of prochlorperazine maleate and the relative standard deviation is 0.68%. The quantitative
assessment of tolerable amounts of other drugs is also studied.
Received September 22, 2000. Revision June 19, 2001 相似文献
2.
Carmen Cruces-Blanco Antonio Segura Carretero Silvia Fernández Peinado Alberto Fernández Gutiérrez 《Mikrochimica acta》2000,134(1-2):107-111
A spectrofluorimetric method for the determination of methyl paraben based on derivatization with the labelling reagent dansyl
chloride (DNS-Cl), is presented. The effect of the reaction variables (pH, DNS-Cl concentration, temperature, reaction time)
and instrumental parameters, has been examined. A linear calibration graph in the ng/ml range has been established. The limit
of detection is 18 ng/ml with relative standard deviation less than 3%. The proposed method has been satisfactorily applied
to determination of the paraben in two pharmaceutical preparations.
Received May 25, 1999. Revision October 20, 1999. 相似文献
3.
Ewa Bobrowska-Grzesik 《Mikrochimica acta》2001,136(1-2):31-34
Derivative spectrophotometry was applied for the simultaneous determination of amoxycillin and clavulanic acid in pharmaceutical
preparations: “Augmentin” inj. and tablets and “Amoksiklav” drops and tablets, in solutions after hydrolysis with sodium hydroxide.
As the absorption spectra overlap strongly (amoxycillin λmax = 247 nm and 290 nm, clavulanic acid λmax = 258 nm) the first and the second derivative spectrophotometric procedure was elaborated for their determination. Amoxycillin
was determined at λ = 257.9 nm (1-st derivative spectra) or λ = 273 nm (2-nd derivative) while clavulanic acid at λ = 280.3 nm
(1-st derivative) or λ = 285 nm (2-nd derivative spectra). The Beer’s law is obeyed in the range of 0.004–0.04 mg/ml for amoxycillin
and 0.002–0.02 mg/ml for clavulanic acid.
Received December 6, 1999. Revision August 1, 2000. 相似文献
4.
Tehseen Aman Shamma Firdous Islam Ullah Khan Asrar Ahmad Kazi 《Mikrochimica acta》2001,137(3-4):121-126
Phenytoin sodium reacts with o-nitrobenzoic acid in alkaline media after heating for 10 minutes at 70 °C, to give a red coloured
complex having maximum absorbance at 510 nm. The reaction is selective for phenytoin sodium with 0.01 mg/10 mL as visual limit
of quantitation and provides a basis for a new spectrophotometric determination. The colour reaction obeys Beer’s law from
0.01 mg to 3 mg/10 mL of phenytoin sodium and the relative standard deviation is 0.29%. The quantitative assessment of tolerable
amounts of other drugs is also studied.
Received May 2, 2000. Revision May 11, 2001. 相似文献
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6.
《Analytical letters》2012,45(11):2011-2016
Abstract A new spectrophotometric determination of cobalt with 2-hydroxy-1-naphthaldehyde guanylhydrazone in acid medium is described. The method is developed on the basis of a yellow cobalt (III) complex (molar absorptivity 1.32×10?4 L.mol?1.cm?1 at 416 nm, stoichiometry 2:1). The method was applied to the determination of cobalt in vitamin preparations, steel and high-purity iron. 相似文献
7.
微乳液1-(2-吡啶偶氮)-2-萘酚分光光度法测定蔬菜样品中的钴 总被引:7,自引:0,他引:7
以十二烷基硫酸钠-溴代十六烷基三甲胺(SDS-CIMAB)复合微乳液为介质,对Co(Ⅱ)-1-(2-吡啶偶氮)-2-萘酚的显色反应条件进行了研究.结果表明该体系的λ_(max)=580nm,ε_(580)=3.4×10~4L·mol·cm~(-1),Co(Ⅱ)测定的线性范围为0~2.40mg/L.回收率在96%~103%之间,该法选择性好,用于蔬菜中Co(Ⅱ)含量的测定,得到了满意的结果. 相似文献
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Ali Z. Abu Zuhri Nidal A. Zatar Raqi M. Shubietah Hala H. Arafat 《Mikrochimica acta》2000,134(3-4):153-160
Two methods are described for quantitative determination of nizatidine. The first is a cathodic stripping voltammetric method
which is based on the accumulation of the compound at the hanging mercury drop electrode. The adsorptive stripping response
was evaluated with respect of accumulation time, potential, concentration, pH and other variables. A linear calibration graph
was obtained over the range 3.0×10−8–1.0×10−6 M with a detection limit 3.0×10−8 M after a 20s accumulation time at −0.2 V accumulation potential. On the other hand, it was found that the detection limit
could be lowered to 1.0×10−8 M after 180s accumulation time at −0.2 V accumulation potential. The relative standard deviation was in the range 1.2−2.0%
for six measurements. The tolerance amounts of the common excipients have also been reported.
The second is a spectrophotometric method which is based on the formation and extraction of the ion-pair complex formed between
nizatidine and either bromocresol green or bromothymol blue. The extracted colored ion-pair complexes absorb at 416 nm. The
effect of different factors such as: type of organic solvent, pH, reagent concentration, number of extraction times, shaking
time, temperature and the tolerance amount of the common excipients have been reported. The calibration graph was linear in
the range 6.0×10−7–1.8×10−5 M with a detection limit of 6.0×10−7 M and molar absorptivity of 2.1×104 lċmol−1ċcm−1 when using bromocresol green, while the calibration graph was linear in the range 3.0×10−7–1.1×10−5 M with a detection limit of 3.0×10−7 M and molar absorptivity of 3.2×104 lċmol−1ċcm−1 when using bromothymol blue. The spectrophotometric methods offer alternative methods with reasonable sensitivity, selectivity
and accuracy with relative standard deviation in the range 2.1−6.0% and 1.2−4.7% (for six measurements) when using bromothymol
blue and bromocresol green, respectively. The proposed two methods were applied for the determination of nizatidine in commercially
available dosage forms. A comparison between the voltammetric and the extraction-spectrophotometric methods was also reported.
Received April 19, 1999. Revision August 30, 1999. 相似文献
10.
Two simple, fast, accurate and precise methods for the determination of six phenothiazines and a number of their pharmaceutical
formulations are described. The titrimetric method involves the oxidation of the drugs by metavanadate in sulphuric acid medium
and titration of vanadium(IV) formed, with cerium(IV) using ferroin indicator and acetone as catalyst. In spectrophotometry,
vanadium(IV) formed was reacted with ferriin and the resulting ferroin measured at 510 nm. Phenothiazines in the ranges 5–100 mg
and 2.5–25.0 μg mL−1 can be determined by titrimetry and spectrophotometry, respectively, with detection limits of 0.96–2.05 mg and 0.0359–0.0565 μg mL−1, respectively. Both methods were applied successfully to the determination of the studied drugs in pharmaceutical preparations.
The reliability of the assays was established by parallel determination by the official methods of British Pharmacopoeia and
the results being statistically evaluated.
Received September 26, 2000. Revision March 25, 2001. 相似文献
11.
《Analytical letters》2012,45(9):1933-1941
Abstract Ranitidine hydrochloride in tablets (T) and injections (I) was determined by ultraviolet spectrophotometry (UVS) at 313 nm and visible spectrophotometry (VISS) at 615 nm, after reaction with 3-methyl-2-benzothiazolinone hydrazone hydrochloride (MBTH) and ferric chloride. For UVS, Beer's law was obeyed in the range 5.0 – 18.0 μg/mL. The coefficients of variation (CV) for the samples T were 0.36% and 0.71% and for the samples I were 0.51% and 0.24%. The recovery average (RA) was 99.88%. For UVS, Beer's law was observed in the range 1.44 – 5.76 μg/mL. The CV for T were 0.72% and 0.59%, and for I were 0.53% and 0.61%. The RA was 99.39%. The precision and accuracy of the two methods were compared. 相似文献
12.
Pilar Viñas Carmen López-Erroz Francisco Joseé Cerdán Natalia Campillo Manuel Hernández-Córdoba 《Mikrochimica acta》2000,134(1-2):83-87
A new fluorimetric procedure for the determination of thiamine using flow injection analysis is proposed. The method is based
on the derivatization reaction of the primary amine group with o-phthalaldehyde in the presence of 2-mercaptoethanol using fluorimetric detection. The calibration graph based on peak area
was linear in the range 0.2–6 ng mL−1. The detection limit was close to 0.1 ng mL−1. The method was applied to the determination of the vitamin in commercial pharmaceutical preparations.
Received March 31, 1999. Revision October 15, 1999. 相似文献
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研究了铜与1-(2-吡啶偶氮)-2-萘酚(PAN)在微乳液中的显色反应,建立了测定硫酸阳极氧化液中铜的新方法。以微乳液为增溶增敏剂,在酸性条件下使Cu-PAN络合物稳定保持在水相中,直接进行光度分析。该体系的络合物在558 nm处有最大吸收峰,线性范围为0~2.8μg/mL,其表观摩尔吸光系数ε=2.32×104L.mol-1.cm-1,该法用于测定硫酸阳极氧化液中的铜在不同水平的加标回收率为96.3%~102.1%。结果表明,该法准确、快速、简便,其它的常见离子无干扰。 相似文献
16.
Sérgio L. C. Ferreira Neyla M. L. Araújo Adriana B. Santos Alailson F. Dantas A. C. Spinola Costa 《Mikrochimica acta》1995,118(1-2):123-129
TAN reacts with zinc(II) forming a red complex with composition 1:2 Zn(II)-TAN and absorption maximum at 582 nm. Zinc can be determined with this reagent in the presence of Triton X-100, in the pH range 6.20-8.00 with a molar absorptivity of 4.5×104 l/mol/cm Beer's Law was obeyed up to least 1.55 g/ml. Copper interference was eliminated with a mixture of thiosulfate and ascorbic acid and nickel separated by precipitation with dimethylglyoxime. The proposed method was used for zinc determination in several copper-base alloys and the results of analysis in comparison with certified values indicated that the procedure was accurate and precise. A derivative procedure is also proposed, allowing zinc determination with high sensitivity (5-400 ng/ml). 相似文献
17.
《Analytical letters》2012,45(9):1673-1686
Abstract A first derivative spectrophotometry method has been developed for the simultaneous quantitation of minoxidil and tretinoin. The method is based on measuring the first derivative signals (D1) of minoxidil and tretinoin at 290 and 351 nm, respectively, without any interference from each other, or any other coexisting materials. Beer's law was valid over the concentration range 2–10 μg/ml of minoxidil and 0.25–1.25 μg/ml of tretinoin. The proposed method has been applied successfully to the determination of some magistral and pharmaceutical preparations. Relative standard deviations for the assay of both drugs were less than 0.95%. 相似文献
18.
Three simple and sensitive colorimetric methods (A–C) for the determination of melatonin in bulk samples and in pharmaceutical
formulations are described. They are based on the formation of coloured species by reaction of ninhydrin with the drug (method
A, λmax 397 nm) by oxidation of the indol moiety in melatonin with potassium persulphate (method B, λmax 450 nm) or by reduction of osmium (VIII) (method C, λmax 516 nm). Regression analysis of Beer-Lambert plots showed good correlations in concentration ranges between 0.8–14.2, 70.0–140.0
and 2.0–40.0 μg/mL for methods A, B and C, respectively. The molar absorptivity, Sandell sensitivity and detection limit were
calculated. For more accurate analysis, Ringbom optimum concentration ranges were calculated. The validity of the proposed
methods was tested by analysing pharmaceutical formulations containing melatonin. The relative standard deviations were ≤ 0.95%
with recoveries 99.0–101.33%.
Received October 20, 1999. Revision February 10, 1999. 相似文献
19.
Saadia M. El-Ashry Fathalla Belal Mohamed M. El-Kerdawy Dalia R. El Wasseef 《Mikrochimica acta》2000,135(3-4):191-196
A simple and sensitive spectrophotometric method is described for the determination of some phenolic antibiotics namely:
cefadroxil, amoxicillin and vancomycin. The method is based on the measurement of the orange yellow species produced when
the drugs are coupled with diazotized benzocaine in triethylamine medium. The method is applicable over the range of 0.8–12 μg/ml
for cefadroxil, 2–16 μg/ml for amoxicillin and 2–18 μg/ml for vancomycin. The formed compounds absorb at 455 nm for both cefadroxil
and amoxicillin and at 442 nm for vancomycin. The proposed method has detection limits of 0.018 μg for cefadroxil, 0.0034 μg
for amoxicillin and 0.0156 μg for vancomycin.
The stoichiometric ratio for the studied compounds was found to be 1:1 and a proposal of the reaction pathway was made. The
proposed method was applied for the analysis of the cited drugs in their pharmaceutical preparations. The results are in good
agreement with those obtained by the official methods.
Received February 7, 2000. Revision June 14, 2000. 相似文献
20.
Using two statistical models, based on the two-level full factorial designs and sequential experimental Doehlert designs,
a simultaneous determination of cadmium and zinc by solid-phase derivative spectrophotometry has been proposed. These chemometric
techniques have been used for the optimization of the instrumental and experimental variables of the system. The complexes
formed between cadmium and zinc with 4-(2-pyridylazo) resorcinol, in the presence of potassium iodide, were fixed on a dextran-type
anion-exchange gel, at pH 8.7. The absorbance spectra of the gel, packed in a 1-mm cell, were recorded directly. The performance
characteristics of the proposed method have been established. The method was applied to the simultaneous determination of
both analytes in synthetic mixtures and natural water samples.
Received November 26, 1998. Revision November 10, 1999 相似文献