• 약학회지
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• 제35권3호
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• pp.182-189
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• 1991

Systematic study on the extraction of ion pair by the use of picric acid (PCA) as an ion pair forming reagent to the aliphatic amines has not be done by spectrophotometric method. The extraction of ion pair by the use of PCA and 23 kinds of the aliphatic amines was examined. The procedure is as follows; Elving's buffer solution (pH 1.3~10, ionic strength 0.5) each amine solution, and PCA solution were taken into a test tube. The mixture was shaken mechanically with chlorform. The organic phase was filtered through a filter paper to remove water droplets. The absorbance was examined at $\lambda_{max}$ against a reagent blank. Primary and secondary whose carbon number were more than 7 or 6, respectively, are extractable as ion pairs with PCA, while tertiary amines and quaternary ammonium salts are also extractable without the correlation of carbon number. It was considered that the ion pair extraction of primary and secondary amines was affected by the number of carbon of amines, but its extraction of tertiary amines or quaternary ammonium salts was affected by kind of aliphatic amines rather than pKa values or carbon number of amines.

• Archives of Pharmacal Research
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• 제13권2호
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• pp.174-179
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• 1990

Second derivative (D2) spectrometry using ion-pair extraction technique was development for the determination of total glycyrrhetic acid (GA) in Glycyrrhizae Radix, Glycyr-rhizin (G) obtained from Glycyrrhizae Radix was hydrolyzed into GA in 2 N-HCI and methanol (1:1) and extracted from aqueous phase in the form of an ion-pair complex with tetrapentylammonium bromide (TPA) as a counter ion. Maximum D2 amplitude (Z value) was obtained when 1000-fold or greater molar ratio of TPA was used at pH 11. Reaction an effective extraction solvent of the ion-pair complex. The linearity of standard curve of ion-pair GA was obtained in the range of 4.120 $\mu$g/ml as GA. Assayed contents of GA in dry powder by D2 UV spectrometry and HPLC method were 5.31 $\pm$ 0.04% and 5.20 $\pm$ 0.008%, respectively.

• Bulletin of the Korean Chemical Society
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• 제23권10호
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• pp.1381-1391
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• 2002

The solvent sublation using ion pairs of metal-2-naphthoate(2-HNph) and tetrabutyl ammonium ($TBA^+$) ion has been studied for the concentration and determination of ultra trace Bi(III), In(III) and Tl(Ⅲ) ions in water samples. The partition coefficients ($K_p$) and the extraction percentages of 2-HNph and the ion pairs to methyl isobutyl ketone (MIBK) were obtained as basic data. After the ion pair $TBA^+$·M$(Nph)_4^-$ was formed in water samples, the analytes were concentrated by the solvent sublation and the elements were determined by GF-AAS. The pH of the sample solution, the amount of the ligand and counter ion added and stirring time were optimized for the efficient formation of the ion pair. The type and amount of optimum surfactant, bubbling time with nitrogen and the type of solvent were investigated for the solvent sublation as well. 10.0 mL of 0.1 M 2-HNph and 2.0 mL of 0.1 M $TBA^+$ were added to a 1.0 L sample solution at pH 5.0. After 2.0 mL of 0.2%(w/v) Triton X-100 was added, the ion pairs were extracted into 20.0 mL MIBK in a flotation cell by bubbling. The analytes were determined by a calibration curve method with measured absorbances in MIBK, and the recovery was 80-120%.

• 대한화학회지
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• 제27권6호
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• pp.411-418
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• 1983

HF용액 또는 ${KHF}_2$용액에서 methylene blue의 양이온과 ${BF}_4^-$음이온이 이루는 착물을 1,2-dichloroethane으로 용매추출할 때, 용액 중에 존재하는 $F^-$와 ${HF}_2^-$음이온이 미치는 영향을 분광광도법으로 조사하였다.$F^-$ 이온은 $10^{-2}$의 비교적 진한 농도로 존재하더라도 methylene blue와 이온쌍을 이루지 않으므로 직접적인 영향을 주지 않았다. 그러나 ${HF}_2^-$이온은 ${BF}_4^-$이온과 경쟁적으로 methylene blue와 이온쌍을 이루어 BF4-이온과 함께 추출되는 것으로 보이고 25$^{\circ}C$ 에서 methylene blue-${HF}_2$ 이온쌍의 1,2-dichloroethane용매에 대한 추출상수, $K_{ext}$=8.5를 얻었다.

• 약학회지
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• 제37권2호
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• pp.119-123
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• 1993

A spectrophotomertic method is proposed for the determination of antihistamines. The method is based on solvent extraction of the ion pair formed between antihistamines and colored picric acid into chloroform. The binding state of antihistamines-picric acid complexes were presumed by IR and $^{1}$H-NMR spectra as intermolecular hydrogen bonding. This method was applicable to the determination of antihistamines in the pharamaceutical preparations.

• 약학회지
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• 제27권2호
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• pp.125-131
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• 1983

Whether ($AB_{w}$) may be neglected against ($A_{w}^{+}$) in the calculation of the extraction coefficient of ion-pairs was criticized by both experiments and theoretical consideration, where ($AB_{w}$) and ($A_{w}^{+}$) mean the molar concentration of ion-pair AB and cation $A^{+}$ in the aqueous phase. Ion-pair complexes were partitioned between phosphate buffer (pH 7.4) and n-octanol. Tetrabutylammonium, isopropamide and methylene blue were selected as cations and benzoic acid, p-toluenesulfonic acid, salicylic acid and taurodeoxycholic acid were selected as counter ions (anions). As a result, conventional methods which assume no existence of ($AB_{w}$) were proven to lack generality. The equation proposed in my earlier report was confirmed to be valid as a general method.

• 대한화학회지
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• 제26권5호
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• pp.326-332
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• 1982

플루오르화수소산 존재하에서 methylene blue의 양이온과 $BF_4^-$, 음이온이 이루는 착물을 1,2-dichloroethane과 nitrobenzene으로 용매추출하여 분광광도법으로 분석하였다. 적외선과 가시선 스펙트럼을 조사하여 이 착물은 1:1 조성비를 가지는 ion-pair로 존재하는 것으로 보이며 1,2-dichlorethane 중에서는 해리하지 않는 것을 알아냈다. 1,2-Dichlorethane에 대해서는 HF의 농도가 1.43${\times}10^{-2}$~ 2.86${\times}10^{-1}$M 범위에서 추출상수가 25$^{\circ}$C에서 1.1${\times}10^4M{-1}$로 일정한 값을 나타내었으며 nitrobenzene에 대하여는 대체로 10배 가량 큰 값을 가지지만 HF농도가 증가함에 약간씩 증가하였다.

• Bulletin of the Korean Chemical Society
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• 제22권8호
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• pp.821-826
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• 2001

Solvent sublation has been studied for the separation and determination of trace Zn(Ⅱ) and Pb(Ⅱ) in water samples. A synergy producing method was utilized to improve the efficiency of extraction in the sublation using an ion-pair of metal-naphth oate {M-(Nph)3- } complexes and tetra-n-butylammonium (TBA+ ) ion. After the M-(Nph)3- complexes were formed by adding 1-naphthoic acid to the sample solution, tetra-n-butylammonium bromide was added in the solution to form the ion-pair. And sodium lauryl sulfate (SLS) was added to make the ion-pair hydrophobic. The ion-pairs of the metal complexes were floated and extracted into methylisobutyl ketone (MIBK) from the aqueous solution by bubbling with nitrogen gas in a flotation cell. Metal ions in MIBK solution were measured by graphite furnace-AAS. Experimental conditions were optimized as follow so. After the pH of a 1.0 L water sample was adjusted to 5.0, 6.0 mL of 0.1 M 1-HNph and 10 mL of 0.03 M TBA-bromide were added to the sample to form ion-pairs, and 2.0 mL of 0.2%(w/v) SLS was added to make the ion-pairs hydrophobic. The solution was bubbled with 30 mL/min N2 gas for 5 minutes in a flotation cell. Linear calibration curves were obtained for the determination of Zn(Ⅱ) and Pb(Ⅱ) in several water samples. Reproducible results of showing a relative standard deviation of < 10% and recoveries of 80-100% could be obtained.

• Journal of Pharmaceutical Investigation
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• 제4권1_2호
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• pp.46-54
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• 1974

A new spectrophotemetric method was estalished for the determination of oleic acid. This method is based on the 1,2-dichloroe-thane extraction of the ion-pair formed between methylene blue and oleic acid. But the absorbance of an ion-pair in the 1,2-dichloroe-thane layer was variable with the temperature, the ion-pair was extracted back into a diluted hydrochloric acid solution. The maximum absorbance of the acid extract observed at $660m{\mu}$ and a lineal relationship was observed from the initial amount over the range of $50-800{\gamma}/ml$ of oleic acid in the aqueous phase. The composition ratio of the ion-pair formed between methylene blue and oleic acid was determined to be 2 : 1 by both the mole ratio and continuous variation methods.

• 약학회지
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• 제35권1호
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• pp.15-21
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• 1991

Quaternary amines which are widely used as medicines are nitrogen compounds. Metanil yellow(MY) and benzalkonium chloride(BKC) were mixed and added to 10ml of the buffer solution and then the solution was shaken for 5 minutes. The maximum absorption wavelength of the reaction product was 402 nm. Dichloromethane was the best extracting solvent among the several organic solvents and the most suitable pH range was 2~8. When the BKC-MY calibration curve was made in the best experimental condition, the Lambert-Beer's law was obeyed in the range of BKC concentration of 2$\times$$10^{-6}$~9$\times$$10^{-6}$M by UV spectrophotometer. This method was possible to determine quaternary ammonium salts in the pharmaceutical preparation.