scholarly journals Liquid Chromatographic Determination of Nitrofuran Residues in Bovine Muscle Tissues

1997 ◽  
Vol 80 (3) ◽  
pp. 481-485 ◽  
Author(s):  
Nora M Angelini ◽  
Oscar D Rampin ◽  
Héctor Mugica
Keyword(s):  
Mobile Phase ◽  
Chromatographic Determination ◽  
Reversed Phase ◽  
Uv Spectra ◽  
Array Detector ◽  
Bovine Muscle ◽  
Muscle Tissues ◽  
Relative Standard ◽  
Liquid Chromatographic

Abstract A liquid chromatographic (LC) method was developed and statistically validated for simultaneous determination of nitrofurazone, nitrofurantoin, furazolidone, and furaltadone residues in bovine muscle tissues. These antimicrobial residues in samples stabilized at pH 6.0 were extracted with acetonitrile and purified by liquid-liquid partition between dichloromethane-ethyl acetate and hexane saturated with acetonitrile. The acetonitrileethyl acetate extract was concentrated, and drug residues were dissolved in LC mobile phase, filtered, and determined by LC. A Cis reversed-phase (ODS Hypersil) column at 35°C, a mobile phase of 0.01 M sodium acetate buffer (pH 4.5)-acetonitrile (70 + 30), and a UV/visible diode array detector at 365 nm were used. The retention times and UV spectra of peaks in spiked samples were compared with those of known nitrofurans. Limits of detection (LD) and quantitation (LQ) were 1 and 2 μg/kg, respectively. Average recoveries were 76% (range, 60-110%). Relative standard deviations ranged from 6 to 18% at 5 fortification levels from 1.5 to 20 μg/kg. (Fortification levels for furaltadone were 3 to 40 μg/kg). The method was used to analyze 350 samples per year from 1993 to 1995.

scholarly journals Liquid Chromatographic Determination of Scopolamine, Hyoscyamine, and Phenobarbital in Tablets

1997 ◽  
Vol 80 (2) ◽  
pp. 331-334 ◽  
Author(s):  
Susan Ting
Keyword(s):  
Mobile Phase ◽  
Chromatographic Determination ◽  
Reversed Phase ◽  
Scopolamine Hydrobromide ◽  
Acid Sodium Salt ◽  
Liquid Chromatographic Method ◽  
Relative Standard ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A liquid chromatographic method using a reversed- phase C18 column and octanesulfonic acid sodium salt-methanol as the mobile phase was developed for the simultaneous determination of phenobarbi- tal, scopolamine, and hyoscyamine in tablets. The mixture of the 3 drugs was resolved in <8 min. Detector responses were linear for 10 μL injections of the following: scopolamine hydrobromide, 8.25-206.3 μg/mL; hyoscyamine sulfate, 15.01-750.76 μg/mL; and phenobarbital, 250-751 μg/mL. Recoveries from tablets were 100.8% for scopolamine hydrobromide, 100.1% for hyoscyamine sulfate, and 100.3% for phenobarbital. Replicate injections of scopolamine hydrobromide, hyoscyamine sulfate, and phenobarbital gave an overall relative standard deviation of <1.0% (n = 10). The method detected as little as 3.3 ng scopolamine hydrobromide.

Liquid Chromatographic Determination of Vanillin and Related Aromatic Compounds

2000 ◽  
Vol 83 (1) ◽  
pp. 237-240 ◽  
Author(s):  
Eshwar Jagerdeo ◽  
Erin Passetti ◽  
Sumer M Dugar
Keyword(s):  
Aromatic Compounds ◽  
Mobile Phase ◽  
Chromatographic Determination ◽  
Reversed Phase ◽  
Array Detector ◽  
Phase Measurements ◽  
Ethyl Vanillin ◽  
Photodiode Array Detector ◽  
Liquid Chromatographic

Abstract This paper describes a reversed-phase liquid chromatographic method for the determination of vanillin, associated natural aromatic compounds and/or synthetic precursors, ethyl vanillin, and coumarin, a commonly encountered adulterant in nonbeverage and beverage alcohol products using a ternary gradient mobile phase. The compounds were separated on a Nova-Pak C18 column by using water, methanol, and tetrahydrofuran as the mobile phase. Measurements were made by using a photodiode array detector at 275 nm. The choice of the mobile phase and the column provides baseline resolution of vanillin and the associated aromatic compounds commonly found in vanilla-flavoring material. Because this method provides low-level detection/quantitation, it is suitable for the characterization of vanilla flavoring materials that are currently added to vanilla flavored beverage alcohol products.

scholarly journals Liquid Chromatographic Determination of Histamine in Fish, Sauerkraut, and Wine: Interlaboratory Study

1998 ◽  
Vol 81 (5) ◽  
pp. 991-998 ◽  
Author(s):  
Paul R Beljaars ◽  
Remmelt Van Dijk ◽  
Klaas M Onker ◽  
Louis J Schout ◽  
◽  
...  
Keyword(s):  
Mobile Phase ◽  
Chromatographic Determination ◽  
Reversed Phase ◽  
Interlaboratory Study ◽  
Relative Standard ◽  
Liquid Chromatographic Determination ◽  
Standard Deviations ◽  
Liquid Chromatographic ◽  
Postcolumn Derivatization

Abstract An interlaboratory study of the liquid chromatographic (LC) determination of histamine in fish, sauerkraut, and wine was conducted. Diminuted and homogenized samples were suspended in water followed by clarification of extracts with perchloric acid, filtration, and dilution with water. After LC separation on a reversed-phase C18 column with phosphate buffer (pH 3.0)-acetonitrile (875 + 125, v/v) as mobile phase, histamine was measured fluorometrically (excitation, 340 nm; emission, 455 nm) in samples and standards after postcolumn derivatization with ophthaldialdehyde (OPA). Fourteen samples (including 6 blind duplicates and 1 split level) containing histamine at about 10- 400 mg/kg or mg/L were analyzed singly according to the proposed procedure by 11 laboratories. Results from one participant were excluded from statistical analysis. For all samples analyzed, repeatability relative standard deviations varied from 2.1 to 5.6%, and reproducibility relative standard deviations ranged from 2.2 to 7.1%. Average recoveries of histamine for this concentration range varied from 94 to 100%

Improved liquid-chromatographic determination of haloperidol in plasma.

1984 ◽  
Vol 30 (7) ◽  
pp. 1228-1230 ◽  
Author(s):  
A K Dhar ◽  
H Kutt
Keyword(s):  
Mobile Phase ◽  
High Performance ◽  
Room Temperature ◽  
Internal Standard ◽  
Isoamyl Alcohol ◽  
Chromatographic Determination ◽  
Reversed Phase ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract This method for determination of haloperidol in plasma is based on "high-performance" isocratic liquid chromatography with the use of a C8 bonded reversed-phase column at room temperature. Haloperidol and the internal standard (chloro-substituted analog) are extracted from alkalinized plasma into isoamyl alcohol/heptane (1.5/98.5 by vol) and back-extracted into dilute H2SO4. The aqueous phase is directly injected onto the column. The mobile phase is a 30/45/25 (by vol) mixture of phosphate buffer (16.5 mmol/L, pH 7.0), acetonitrile, and methanol. Unlike other liquid-chromatographic procedures for haloperidol, commonly used psychotropic drugs do not interfere. Analysis can be completed within an hour. The procedure is extremely sensitive (1.0 microgram/L) and is well reproducible (CV 5.6% for a 2.5 micrograms/L concentration in plasma).

Improved liquid-chromatographic determination of 3-methoxy-4-hydroxyphenylethyleneglycol in urine with electrochemical detection.

1984 ◽  
Vol 30 (1) ◽  
pp. 140-143 ◽  
Author(s):  
J R Shipe ◽  
J Savory ◽  
M R Wills
Keyword(s):  
Mobile Phase ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Reversed Phase ◽  
Improved Method ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic ◽  
Mean Concentration ◽  
Phase Column

Abstract In this improved method for quantifying 3-methoxy-4-hydroxyphenylethyleneglycol (MHPG) in urine, after a multistep extraction of MHPG and internal standard (iso-MHPG) from 3.0 mL of urine, the compounds are separated on a C18 reversed-phase column and quantified by use of an electro-chemical detector. The isocratic chromatographic separation takes about 16 min. The mobile phase is phosphate buffer/acetonitrile (88/12 by vol), the flow rate 0.7 mL/min. Recycling the mobile phase and automating the sample injection make possible the unattended assay of more than 70 samples per day. The within-run precision of the method is excellent (CV 1.8%) at a mean concentration of 1.1 mg/L.

High Performance Liquid Chromatographic Determination of Primidone in Tablets

1982 ◽  
Vol 65 (5) ◽  
pp. 1063-1065
Author(s):  
Stanley E Roberts
Keyword(s):  
Mobile Phase ◽  
High Performance ◽  
Chromatographic Determination ◽  
High Performance Liquid Chromatographic ◽  
Hplc Method ◽  
Average Recovery ◽  
Relative Standard ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A high performance liquid chromatographic (HPLC) method is described for the quantitative determination of primidone in tablets. A ground tablet sample is diluted directly in the mobile phase, at a concentration of about 1 mg/mL of primidone, mixed and deaerated, and filtered. The resulting solution is then quantitated by HPLC. The average spike recoveries for the 50 mg and 250 mg tablets were 101.2% and 99.0%, respectively. The average recovery for an authentic mixture formulated at the 250 mg level was 100.1% with a relative standard deviation of 0.45%.

scholarly journals Liquid Chromatographic Determination of the Glycoalkaloids α-Solanine and α-Chaconine in Potato Tubers: NMKL Interlaboratory Study

1997 ◽  
Vol 80 (3) ◽  
pp. 549-554 ◽  
Author(s):  
Karl-Erik Hellenás ◽  
Carina Branzell ◽  
H Poutanen ◽  
T Suortti ◽  
R Kaario ◽  
...  
Keyword(s):  
Collaborative Study ◽  
Chromatographic Determination ◽  
Reversed Phase ◽  
Potato Tubers ◽  
Photometric Detection ◽  
Liquid Chromatographic Method ◽  
Relative Standard ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract Twelve laboratories participated in a collaborative study to evaluate precision parameters of a liquid chromatographic method for analysis of the glycoalkaloids α-solanine and α-chaconine in potato tubers. Samples consisted of frozen potato tuber homogenates distributed as 3 blind duplicates and 3 split-level pairs. The analytical method included aqueous extraction, workup on disposable solidphase extraction cartridges, and reversed-phase chromatography with photometric detection at 202 nm. Results for α-solanine and α-chaconine were received from 10 and 9 laboratories, respectively. Relative standard deviations for reproducibilo ity for α-solanine and α-chaconine were similar, ranging from 8 to 13% in the applied concentration range of 12 to 260 mg/kg fresh weight.

Liquid Chromatographic Determination of Vitamin D in Animal Feeds and Premixes

1992 ◽  
Vol 75 (5) ◽  
pp. 812-814 ◽  
Author(s):  
Vipin K Agarwal
Keyword(s):  
Vitamin D ◽  
Mobile Phase ◽  
Potassium Hydroxide ◽  
Chromatographic Determination ◽  
Reversed Phase ◽  
Ultraviolet Detection ◽  
Animal Feeds ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A liquid chromatographic (LC) method has been developed for the determination of vitamin D (D2 + D3) in animal feeds and premixes. The sample is saponified with potassium hydroxide, and vitamin D is extracted with hexane and isomerized to isotachysterol with 10M HCI in 2-butanol. LC determination of isotachysterol to quantitate vitamin D is carried out on a reversed-phase column with acetonitrilemethanol (90 +10) as the mobile phase and ultraviolet detection at 301 nm. The detection limit of the method is 1 lU/g. This method can also be used for the determination of vitamin D2 and D3 separately.

Liquid-chromatographic determination of pentobarbital in plasma with use of a resin column and an alkaline mobile phase.

1982 ◽  
Vol 28 (8) ◽  
pp. 1772-1774 ◽  
Author(s):  
R N Gupta ◽  
P T Smith ◽  
F Eng
Keyword(s):  
Mobile Phase ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Reversed Phase ◽  
Enhanced Sensitivity ◽  
Acidic Drugs ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract We describe a liquid-chromatographic method involving a new, nonsilica column (XAD-2, Hamilton Co.) for pentobarbital in plasma. Plasma is extracted with chloroform after addition of the internal standard, 5-ethyl-5-p-tolyl-barbituric acid. Acidic drugs are back-extracted into alkali, then chromatographed on the resin-base reversed-phase column. The use of alkaline mobile phase allows enhanced sensitivity and detection of barbiturates at 240 nm. The within-run CV for 10 samples was 1.9%, the between-run CV 1.8%. Ten commonly used barbiturates are separated isocratically in less than 15 min. Other commonly prescribed acidic drugs do not interfere with determination of pentobarbital.

Liquid Chromatographic Determination of 2-Chloro-4-nitroaniline, 2-Naphthol, and 2,4-Dinitroaniline in D&C Red No. 36

1993 ◽  
Vol 76 (2) ◽  
pp. 287-291 ◽  
Author(s):  
Alan L Scher ◽  
Nicholas C Adamo
Keyword(s):  
Chromatographic Determination ◽  
Reversed Phase ◽  
Calibration Data ◽  
Reversed Phase Liquid Chromatography ◽  
Relative Standard ◽  
Liquid Chromatographic Determination ◽  
Phase Liquid ◽  
Liquid Chromatographic ◽  
Cellulose Column

Abstract A method is described for the determination of the intermediates and a related impurity in D&C Red No. 36 by reversed-phase liquid chromatography. This method may be used to ensure that limits set forth in the Code of Federal Regulations on the amounts of these 3 impurities in the color are not exceeded. The pigment is dissolved in boiling dioxane and then precipitated. The filtrate is chromatographed by isocratic elution, and then the column is washed and reequilibrated. Impurities were identified as 2-chloro-4-nitroaniline (2-CI-4-NA), 2-naphthol, and 2,4-dinitroaniline (2,4-DNA) by comparison of their retention times and spectra with those of standards. Peak area calibrations were linear to at least 0.375% 2-CI-4-NA, 1.25% 2-naphthol, and 0.025% 2,4-DNA, all with zero intercepts. At the specification levels, 99% confidence limits were 0.30 ± 0.006% for 2-CI-4-NA, 1.0 ± 0.03% for 2-naphthol, and 0.020 ± 0.0004% for 2,4-DNA. The limits of determination calculated from calibration data were 0.019% for 2-CI-4-NA, 0.10% for 2-naphthol, and 0.0014% for 2,4-DNA at the 99% confidence level. Recoveries were 100-104% for 2-CI-4-NA added to purified D&C Red No. 36,100% for 2-naphthol, and 100-110% for 2,4-DNA; relative standard deviations were 0.8-3.4%. A survey of certified D&C Red No. 36 samples showed that the batches contained higher levels of intermediates than were determined previously by a cellulose column method in which the pigment was not dissolved.

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