• 약학회지
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• 제29권4호
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• pp.220-222
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• 1985

Rifampicin reacts with cupric ion to produce rifampicin-Cu(II) chelate (2:1) at pH 6.5, which can be extracted with methylisobutylketone (MIBK). Therefore, rifampicin can be quantitatively, determined by measuring the quantity of Cu(II) in the organic phase by atomic absorption spectrophotometry. Because higher absorbance ratio was obtained in pH 6.0~7.0, buffer solution at pH 6.5 was used in this measurement. Linear relationship was found between absorbance and concentration in the range of 1.0~4.0${\times}10^{-4}M$. This method might be applicable to the determination of rifampicin in the preparations.

• Biotechnology and Bioprocess Engineering:BBE
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• 제2권2호
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• pp.69-72
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• 1997

The pH of microbial culture medium was calculated from equations of equilibrium, meterial balances for ionic components and electro-neutrality theory. Ammonium ion consumption and Acetic acid production are found out to be the major contributors for the alteration of the pH as well as the buffer capacity of the medium. By measuring the buffer capacity on-line, levels of acetic acid were estimated by a software sensor using pH signal in a fermentation process of E.coli growing in a minimal medium. The measured values of acetic acid showed good correlation to those of estimated by the software sensor.

• KSBB Journal
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• 제13권4호
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• pp.461-467
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• 1998

A fermentation system was supplemented with a device for the measurement of the durations of alkali pump feeding for automatic pH control and an A/D convertor for precise monitoring of pH value by computer. A software program was developed to measure buffer capacities from the pH signal and the pH control signal during fermentation. By measuring the buffer capacity on-line, levels of acetic acid were estimated by a software sensor using pH signal in a fermentation process of E.coli growing in a minimal medium. The measured values of acetic acid showed correlation to those of estimated by the software sensor. Lacitic acid production was also successfully estimated by the values of buffer capacities measured on-line.

• 대한전자공학회논문지
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• 제23권1호
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• pp.83-90
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• 1986

A micro pH-ISFET probe, which can be applied to the in vivo measurements of the hydrogen ion concentration in blood, has been developed, and a measuring system equiped with this probe also developed. The pH-ISFET has been fatricated by employing the techniques of integrated circuit fabrication. Two kinds of micro electrode formed around the sensing gate during the wafer process, and the other is a capillary type of Ag/AfCl/sat. KCI reduced in size. This capillary electrode has shown its good performance characteristics so far in the application with ISFET as well as a commercial one. In order to form a micro pH-ISFET probe, this pH-ISFET and well as a commercial one. In order to form a micro pH-ISFET probe, this pH-ISFET and the capillary electrode were built together into a needle tip having 1 mm inner diameter. The chip size of a twin pH-ISFET is 0.8 mmx1.4 mm, the material of the sensing gate membrane is Si3N4, and the sensitivity of the developed probe is about 52mV/pH.

• 보존과학연구
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• 통권20호
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• pp.21-47
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• 1999

According to damage of papers by the chemical cause, papers become to acidify. Among the 3 kinds of method measuring the acidity of paper, one was nondestructive method measuring the surface of the paper by flat type electrode and the others were destructive methods measuring directly by cold water extract method and hot water extract method. In case of the cellulolytic cultural properties, the latter methods were not applied because those methods must bedissociated papers. To measure the paper acidity nondestructively, we investigated the correlation of the nondestructive method and the destructive methods. The conclusions are as follows. 1) In the relationship of the cold water extract method and the hot water extract method, It was indicated that the pH measured by the hot water extract method was high quality printing paper 0.08, rough printing paper 0.13, and Korean paper 0.29 higher than that by the cold water extract method.2) In the relationship of the cold water extract method and the surface measurement method, It showed that the pH value measured by the cold water extract method was high quality printing paper 1.86, rough printing paper 0.80,and Korean paper 0.58 higher than value that by the surface measurement.3) In the relationship of the hot water extract method and the surface measurement method, It showed that the pH value measured by the hot ABSTRACT water extract method was high quality printing paper 1.78, rough printing paper 0.66, and Korean paper 0.29 higher than that by the surface measurement. From the above-mentioned results, the pH value measured by the surface measurement was need to high about 1.78∼1.86 in high quality printing paper, 0.66-0.80 in rough printing paper, and 0.29∼0.58 in Korean paper and the surface measurement with flat type electrode was very available to measure the acidity of Korean papers actually.

• 보존과학연구
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• 통권20호
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• pp.49-64
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• 1999

According to damage of papers by the chemical cause, papers become to acidify. Among the 3 kinds of method measuring the acidity of paper, one was nondestructive method measuring the surface of the paper by flat type electrode and the others were destructive methods measuring directly by cold water extract method and hot water extract method. In case of the cellulolytic cultural properties, the latter methods were not applied because those methods must bedissociated papers. To measure the paper acidity nondestructively, we investigated the correlation of the nondestructive method and the destructive methods. The conclusions are as follows. 1) In the relationship of the cold water extract method and the hot water extract method, It was indicated that the pH measured by the hot water extract method was high quality printing paper 0.08, rough printing paper 0.13, and Korean paper 0.29 higher than that by the cold water extract method.2) In the relationship of the cold water extract method and the surface measurement method, It showed that the pH value measured by the cold water extract method was high quality printing paper 1.86, rough printing paper 0.80,and Korean paper 0.58 higher than value that by the surface measurement.3) In the relationship of the hot water extract method and the surface measurement method, It showed that the pH value measured by the hot ABSTRACT water extract method was high quality printing paper 1.78, rough printing paper 0.66, and Korean paper 0.29 higher than that by the surface measurement. From the above-mentioned results, the pH value measured by the surface measurement was need to high about 1.78∼1.86 in high quality printing paper, 0.66-0.80 in rough printing paper, and 0.29∼0.58 in Korean paper and the surface measurement with flat type electrode was very available to measure the acidity of Korean papers actually.

• 대한화학회지
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• 제37권2호
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• pp.199-205
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• 1993

구리-아민류착물에 의한 과산화수소의 초기분해속도를 pH7.3~11.8 범위에서 측정하였다. 과산화수소의 분해속도는 pH에 따라 증가하였다가 감소하였다. 이들 실험결과에 일치하는 가능한 메카니즘이 제안되었다. 이 메카니즘은 과산화수소와 구리-아민류착물의 탈양성첨가를 거친 다음에 속도 결정단계에서 퍼옥소구리착물이 생성되는 반응과정과 일치한다.

• 센서학회지
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• 제13권3호
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• pp.213-217
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• 2004

The general method to find a H. pylori in the stomach is the rapid urease test but it is only used to decide the infection with H. pylori. In this study, it is tried to develope fiber-optic pH sensor which can be used with gastroscop to quantify H. pylori. To measure the degree of infection with H. pylori, the color change of phenol red according to the degree of pH is measured by optical fibers with different light sources and the optimum distance from a sample to the end of sensor tip is decided by measuring the maximum reflectivity from a sample. Also the sensitivity study is carried out to decide the optimum light source which has sensitive change of reflectivity to the change of pH. It is expected that the fiber-optic pH sensor which measures the degree of infection with H. pylori exactly can be developed.

• 한국식품위생안전성학회지
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• 제8권2호
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• pp.91-95
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• 1993

사람의 장내세균으로부터 분리된 Bibidobacterium과 Lactobacillus는 대두 및 당근의 물추출물을 이용할 경우 균의 성장과 더불어 배지의 pH는 상대적으로 저하시켰으며, 대두와 당근의 물 추출물은 사람의 장내 세균총 중에서 유산균증식작용이 있었으며, 이와 함께 배지의 pH는 상대적으로 감소하였다. 검체 식품함유 GAM 배지에 사람의 신선한 분변을 이식하여 pH를 측정함으로써 간단하게 유산균증식작용 뿐만 아니라 건강식품을 조사할 수 있었다. 이 방법에 의해 조사한 결과 유산균 증식 효과인 pH를 저하시키는 식품은 대두, 순무, 당근, 영양부추, 마늘, 미나리, 쑥, 양파가 있었다.

• 전기전자학회논문지
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• 제17권4호
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• pp.398-406
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• 2013

핵의학 영상 기기인 양전자 방출 단층 촬영 장치(Positron emission tomography: PET)와 같은 진단기기는 방사성의약품을 인체에 주입하여 질병을 진단한다. 이 때 사용되는 방사성의약품은 안전성을 위하여 적절한 수소 이온농도를 가져야 한다. 일반적으로 방사성 의약품의 수소 이온 농도를 측정하는 과정에서 흔히 사용되는 것이 pH시험지이다. 표본을 pH 시험지에 떨어뜨려 pH 시험지의 변색 정도를 표준색상표(Standard color chart)와 비교하여 표본의 pH를 알 수 있다. 그러나 이 방법은 측정자의 경험 정도에 따라 pH 측정값에 차이가 발생할 수 있다. 또한 pH 메타기는 고감도의 센서를 사용함으로 오염에 주의해야 한다. 이러한 불편함을 고려하여 쉽고 간단하게 정확한 pH를 측정하기 위한 새로운 장치 제작과 영상 기반 알고리즘을 통한 소프트웨어를 개발하였다. 이렇게 개발한 장치는 최종적으로 방사성의약품의 생산 시 품질관리(QC) 통합 제어 시스템으로 사용된다.