Abstrakt

Barbital assay by reversed phase high performance liquid chromatography

Ronald Bartzatt Sarah Ehlers, Nancy Handler

Diethylbarbituric acid (barbital), a hypnotic and sleeping aid, is assayed by reversed phase high-performance liquid chromatography utilizing a column havingoctadecylsilyl (C-18) covalently bonded onto silica.All the test samples and column solvent wasprepared in 95% ethanol and 5% water. The barbital drug efficientlysolubilized into this solventsystem and was stable for hours prior to analysis. Barbital eluted from the column consistentlyat 1.7minutes. The minimumconcentration of analyte detected in this work is0.0001680 molar which is 0.0309 milligrams/milliliter. The highest concentration utilized in this work at 0.03669 molaror 6.758 milligrams/milliliter. The standard curve utilized for test determination had correlation coefficient of PearsonÂ’s r = 0.9992 (R2 = 0.9984). The percent recovery rates for barbital showed a mean of 97.0%and standard deviation ± 1.58% (standard error = 0.345, mode = 96.9, sample variance = 2.50, kurtosis = -1.28) andmedian of 97.5%.Askewness value of 0.101for percent recovery indicates the percent recovery rates are highly symmetric. The SpearmansÂ’ rsof 1.000 for actual and calculated molaritiesindicating extremely high positive correlation.