Abstract: �The permeabilities of planar lipid bilayer (egg phosphatidylcholine-decane) membranes to butyric and formic acids were measured by tracer and pH electrode techniques . The purposes of the study were (a) to establish criteria for the applicability of each method and (b) to resolve a discrepancy between previously published permeabilities determined using the different techniques . Tracer fluxes of butyric acid were measured at several concentrations and pH's . Under symmetrical conditions the one-way flux of butyric acid (j) is described by 1/f = 1/Pu l ([HA] + [A- ]) + 1/P'([HA]), where P°' and P'° are the unstirred layer and membrane permeability coefficients . Pm determined in this manner is 950 X 10-4 cm S-1 . Published values for the butyric acid permeability for egg phosphatidylcholine-decane bilayers are 11 .5 X 10-4 (Wolosin and Ginsburg, 1975) and 640 X 10-4 cm S-1 (Orbach and Finkelstein, 1980) . Wolosin and Ginsburg measured net fluxes from a solution of pH = pKe into an unbuffered solution containing a pH electrode . Orbach and Finkelstein measured tracer fluxes under symmetrical conditions at pH 7.4 . We reproduced the results of Wolosin and Ginsburg and showed that their apparently low P' was caused by unstirred layer effects in their poorly buffered solutions. The permeability to formic acid (pK. = 3.75) measured by both tracer and pH electrode techniques was _ 10-2 cm s-1 . However, if P' > P'l , the pH electrode technique cannot be used for measuring the permeabilities of weak acids with pK8's greater than ^-4 .

Abstract: By measuring the rate of exchange at chemical equilibrium of 18O between HCO3- and H2O catalyzed by human carbonic anhydrase II in the absence of buffers, we have determined the rate of release from the enzyme of water bearing substrate oxygen. The ratio of this rate measured in H2O to the rate measured in D2O, the solvent deuterium isotope effect, is between 4 and 9 in the range of pH(D) from 5.8 to 8.0, with a value of 8.0 +/- 0.7 at pH(D) 6.6 (uncorrected pH meter reading). The magnitude of this isotope effect at pH(D) 6.6 has an exponential dependence on the atom fraction of deuterium in solvent water. We conclude that an intramolecular proton transfer between a proton shuttle group on the enzyme and the active site is rate limiting for the release from the enzyme of water bearing substrate oxygen and involves a change in bonding of more than one proton. In contrast, the solvent deuterium isotope effect on the intermolecular proton transfer between the external buffer imidazole and the active site (or proton shuttle group) of the enzyme is small, 2.3 at pH(D) 7.0, as determined from initial velocity experiments. With a rate constant near 9 X 10(8) M-1 s-1, this intermolecular transfer is limited to a significant extent by diffusion processes.

Abstract: The effect of diltiazem on ischemic myocardial acidosis was studied in the canine heart whose left anterior descending coronary artery was partially occluded to reduce coronary flow to about one-third (partial occlusion). Myocardial pH was measured by use of a micro glass pH electrode. The pH decreased from 7.53 to 6.93 by partial occlusion and appeared to reach a steady state within 30 min. Saline or drugs were injected i.v. 30 min after partial occlusion. The decreased pH increased spontaneously by 34% of the total reduction of pH in the next 60 min after saline injection. Diltiazem (100 micrograms/kg) potentiated the increase in pH; the pH increased by 76% 60 min after the injection. Propranolol (1 mg/kg) also potentiated the increase in pH that had been decreased by partial occlusion. The relation between pH decrease and the tissue levels of metabolites was also studied. The reduction of myocardial pH from 7.5 to 6.8 was accompanied by a 2-fold increase in the tissue lactate content and by decreases in the ATP and creatine phosphate contents. There was a significant correlation between the hydrogen ion concentration calculated from the pH and each of the lactate, ATP and creatine phosphate contents. The present study indicates that diltiazem attenuates ischemic myocardial acidosis.

Abstract: Monocrystalline antimony electrodes have been shown to be suitable for thein vivo determination of pH in blood, tissue and in the upper gastro-intestinal canal. Thanks to their small dimensions it has been possible to mount them into conventional manometry catheters for oesophageal investigation. The monocrystalline antimony pH electrode has several advantages over the conventional pH glass electrode; better accuracy, shorter rise time, smaller dimensions. The monocrystalline antimony electrode has been used for long-term registration of gastro-oesophageal reflux, for the oesophageal acid clearing test and for identification of the pH gradient zone between the gastric and oesophageal mucosa. Its use in combination with pressure sensors has added a new dimension to the diagnosis of functional disorders in the gastro-oesophageal region.

Abstract: Several new electrochemical devices designed for detecting ammonia and carbon dioxide in physiological samples have in common the elimination of the fragile glass pH internal electrode used in the conventional Severinghaus-design potentiometric gas sensors. In one new approach, the pH glass electrode can be replaced with a neutral carrier-based polymer-membrane pH electrode. Alternatively, to improve response characteristics and selectivity, we have used ion-selective polymer membranes responsive to ammonium and carbonate as internal sensing elements in conjunction with appropriate internal buffer reagents. The use of inner polymer membranes rather than glass membranes enables the fabrication of essentially disposable devices having rapid response times. In addition, we have constructed automated continuous-flow NH3- and CO2-sensing systems involving novel tubular forms of the polymer-membrane electrodes and a simple flow-through gas dialysis arrangement. The polymer electrode-based systems described offer many unique and practical advantages over existing gas-sensing units.

Abstract: • Recent reports emphasized the importance of maintenance of a high intragastric pH to prevent gastric mucosal bleeding in acutely ill patients. In this study gastric fluid pH determinations were compared with determinations obtained using an intragastric pH electrode. There was poor correlation between pH determinations obtained by a bare intragastric electrode in contact with the mucosa and pH determinations on fluid aspirated from the stomach. During cimetidine administration mucosal and fluid determinations correlated well, whereas during antacid administration mucosal pH was significantly lower than gastric fluid pH. These results suggest that during antacid administration pH determinations on gastric contents with pH paper may not accurately reflect the pH at the mucosal surface. ( Arch Surg 1982;117:288-291)

Abstract: The relationship between changes in myocardial tissue pH and local coronary venous pH during and after transient occlusion of the left anterior descending artery was investigated in 6 open chested anesthesized dogs. Tissue pH was recorded with a needle pH electrode, and coronary venous pH with a specially designed catheter tip pH electrode. Myocardial tissue pH fell steadily after coronary occlusion, and had fallen by 0.107 +/- 0.043 pH units (mean +/- SD, n = 12, occlusions) after 150 s. On reperfusion there was a further small fall in tissue pH to 0.138 +/- 0.035 units before tissue pH returned to control. In contrast, the fall of coronary venous pH during ischemia was small (0.15 +/- 0.027 after 150 s, n = 12 occlusions). Within 5 s of reperfusion, a large fall in venous pH occurred, reaching a maximum of 0.150 +/- 0.072 at 20-30 s after reperfusion. During ischemia changes in tissue pH are poorly represented by changes in coronary venous pH. The size of early change of venous pH during the reperfusion washout of retained metabolites is a better estimate of the fall of tissue pH. Measurement of metabolites in the coronary sinus of man during the washout after the end of an ischemic intervention such as a trial pacing is superior to measurements performed during pacing in providing biochemical evidence of myocardial ischemia.

Abstract: The determinazione of HCG is performed by the enzyme immunoassay technique using acetylcholinesterase enzyme as lable and a pH electrode to follow the enzyme activity. The antibody to HCG is immobilized in a membrane form with a polyethylene net; to the sample a certain amount of enzyme-labeled HCG is added, the antibody bound membrane is dipped for two hours; after it is taken out, washed and immersed in an acetylcholine Solution and a pH variation can be detected by placing a glass pH electrode with flat surface against the memberane for a few minutes. the pH variation is related tio the HCG concentration of the sample.

Abstract: A measuring electrode device comprises a pH electrode arranged within an outer casing and having a pH sensitive member in contact with an electrolyte housed in the outer casing. The electrolyte reacts with a predetermined gas in a liquid to be inspected and varies its pH. The pH sensitive member includes a semiconductor substrate and a pH sensitive membrane formed on the substrate and in contact with the electrolyte. The pH sensitive membrane is formed of at least one element selected from the group consisting of silicon nitride, aluminum oxide and tantalum pentoxide. A potential difference is produced between the pH sensitive membrane and the electrolyte in accordance with the variation of the pH of the electrolyte. Thus, a potential difference is produced between the pH electrode and a reference electrode according to the variation of the pH of the electrolyte.

Abstract: Monocrystalline antimony catheter electrodes were studied intra-arterially in non-heparinized dogs The sensitivity for variations in arterial Po2 (Pao2) was evaluated for this kind of metal-metal oxide pH sensor The influence of Pao2 compensation on a previous pH sensitivity estimate was calculated When the mV signal from the antimony sensor, after compensation for pH and temperature variations, was expressed as a function of log10 Pao2, a non-linear relation was found for the Pao2 range studied, 29–50 kPa After calculations this range was divided into a lower and a higher sub-range A first-order linear approximation was applied for these subranges The sensitivity for oxygen was 70 mV/log10 Pao2 in the range 29 kPa < Pao2 < 10 kPa, and 207 mV/log10 Pao2 in the range 10 kPa < Pao2 < 50 kPa The non-logarithmic sensitivity for intra-arterial oxygen is contradictory to results from in vitro studies in test solutions The present study indicates that the monocrystalline antimony pH sensor has a sensi

Abstract: The pH of boiler feedwater is raised by the addition of ammonia to a level at which corrosion of the boiler is limited and consequently the measurement of pH is of primary operational interest. It is considered necessary to refer this measurement to a standard temperature of 25 °C because under conditions of varying sample temperatures, some pH meters will record changes in pH that are solely due to the effects of temperature on the chemical equilibrium of the ammonia-dosed water. At present, readings at a reference temperature can be made by controlling the sample temperature or by inclusion of additional compensation circuits in the pH meter. An attractive alternative to either of these methods is the use of self-temperature-compensating electrodes whose physico-chemical properties compensate for the temperature-induced changes in the pH of the sample.When the experimental glass and reference electrodes were tested in simulated ammonia-dosed boiler feedwater over the temperature range 15–35 °C the temperature compensation gave an accuracy of ca.±0.05 pH about the value predicted at 25 °C. Use of these electrodes gives an improvement over those previously reported, in that glass electrodes are more stable and their thermal capacities match more closely those of the reference electrodes.

Abstract: To evaluate tissue surface pH as an indicator of the acid base status of arterial blood during periods of reduced blood flow, we examined the relationship between tissue surface pH, arterial pH, arterial lactic acid levels, and base deficit in fifteen spontaneously breathing anesthetized cats. Blood flow was reduced by hemorrhage to 50% of control blood pressure values (Fig. 3) or by infusing norepinephrine (10 mcg/kg/min intravenously) for one hour (Fig. 2). During these procedures, tissue surface pH was inversely related to arterial base deficit (r = - 0.665, p less than 0.02) and lactic acid (r = 0.822, p less than 0.001) but not related to blood pH (Fig. 4). The errors resulting from measuring tissue surface pH continuously for 2 1/2 to 8 hours were examined by comparing the in vivo recalibration drift of the electrodes. The pH and reference electrodes drifted less than 0.1 pH units during this time. However, when examined in separate experiments for recalibration drift in vitro, we observed up to 0.67 pH units drift after 24 hours of reference electrode contamination with blood, but only 0.02 pH units drift in the pH electrode after this period. Since tissue surface pH is linearly correlated with the blood concentration of lactic acid or the base deficit during periods of acute blood flow reduction, tissue surface pH monitoring may be helpful for following the severity of the resulting anaerobic metabolism in neonates at risk for reduced peripheral perfusion or hypoxia. However, improvements in the reference electrode will be necessary to make long term tissue surface pH monitoring reliable if there is a reasonable risk of contamination of the reference electrode with blood.

Abstract: PURPOSE:To enable a continuous pH measurement without blocking the movement of a culture solution by fitting an O ring into an annular groove provided on the outer wall of an external wall of an outer tube housing a pH glass electrode, a comparison electrode and the like to fix it tight on a nozzle provided on the side of a shaker flask for cultivation or the like. CONSTITUTION:A nozzle 2 is provided on the side wall of a flask 1. A comparison electrode 5 is wound around the external wall of a pH glass electrode 4 in an outer tube 3 of a pH electrode and then, an internal liquid 6 for comparison electrode is placed into an circular space between the internal wall of the outer tube and the electrode 4. A glass induction section 9 of the pH glass electrode 4 and a liquid communication section 11 are fastened on the flask 1 side of the outer tube 3 with a silicon rubber and the internal liquid is sealed into the glass and the electrode 4 together with a liquid holder 13 such as cotton so that the internal liquid can be kept in contact with the inner surface of the induction section constantly during the shaking. Then, a hole 12 for injecting the comparison electrode internal liquid is provided on the back wall of the outer tube 3, which is closed with a flange 8. Annular grooves, for example, two in the number are provided on the external wall of the outer tube 3 and inserted tight into the nozzle 2 with O rings 7 fitted thereinto respectively.

Abstract: PURPOSE:To accomplish favorable flocculation using a flocculant and a reduced amount of alkali chemicals by method wherein alkali chemicals are added to raw water at the maximum addtion ratio selected from addition ratios which are so determined as to cause the alkalinity of raw water, the alkalinity and the pH of flocculation-treated water to become at least specified values. CONSTITUTION:The alkalinity A1 of the raw water entering a feed well 1 is measured by an alkalinity meter and is inputted to an addition ratio calculating circuit 11. The flow rate Q0 of the raw water flowing from the well 1 into a rapid agitation basin 2 is measured by a flowmeter 5, and the alkali chemicals are added into the raw water by an alkali chemical adding device 6. After adding the flocculant into the raw water in the basin 2, the alkalinity A2 and the pH of the flocculation-treated water are measured by an alkalinity meter 8 and a pH meter 9, respectively. Addition ratio calculating circuits 12, 13 calculate the addition ratios alpha3, alpha2 according to the values measured at the meters 9, 8 respectively. A maximum value selecting circuit 14 selects the maximum ratio alphamax from among the addition ratios obtained by the calculating circuits 11-13, and feeds it to an addition amount calculting circuit 15. The circuit 15 claculates an addition amount from the above flow rate Q0 and the addition ratio alphamax, and in accordance with the ad dition amount thus calculated, the adding device 6 adds the alkali chemicals to the raw water.

Abstract: PURPOSE:To easily measure pH without requiring any intricate operation by bundling hair, spraying distilled water thereto to make the same wet, and inserting a pH electrode into this wet hair bundle. CONSTITUTION:A hair bundle 1 is formed by bundling the hair 2 produced by cutting the hair of the head prior to application of cold waving in beauty treatment or hairdressing to a size of about 1.5-3cm diameters. Distilled water of an ordinary temp. is sprayed toward this bundle 1 to make the same wet sufficiently. The leading end of the electrode 5 of a pH measuring device 4 is inserted into the bundle 1 wet in this way, and the potential at an ordinary temp. is measured. To insert the electrode 5 into the bundle 1, it is inserted 1.2-2cm into the bundle 1 so that the internal saturated potassium chloride soln. oozes from the leading end of a calomel reference electrode into distilled water 3, and it is so inserted that the saturated potassium chloride soln. diffused thoroughly to the outer side of the calomel reference electrode in the distilled water 3.

Abstract: An add‐on device for the automatic adjustment of solution pH is described which can be used with any pH meter with an alarm circuit. The desired pH is keyed into the pH meter, and the add‐on device controls the addition of acid or base until the desired pH is attained. Unbuffered solutions can be automatically adjusted to within 0.1 pH unit and buffered solutions to within 0.005 pH unit.

Abstract: PURPOSE:To maintain a pH value suitable for generation of methane gas, when organic sludge is digested with anaerobic bacteria, by conducting divided injection of the while sludge to be charged when the interior of a digestion vessel comes at a predetermined pH level. CONSTITUTION:When concentratied sludge is charged into a digestion vessel 1, the pH value of a liquid is lowered by generation of organic acids. The generated organic acids are then decomposed into methane gas or the like, so that the pH value is raised again and returned to its original level. The pH value is detected by a pH meter 2, and compared with a preset pH value suitable for generation of methane gas by a comparing circuit 3. If the pH value in the digestion vessel 1 exceeds the preset value, a command to drive a sludge-charge pump 7 for a certain period is outputted. Thus, the pH value suitable for generation of methane gas is maintained properly without so much variation in the pH value of the sludge in the digestion vessel 1, so that methane gas generating efficiency can be enhanced.

Abstract: PURPOSE:To reduce a COD value and to eliminate a malodorous source, by adding a hypochlorite, acidic substance and then reducing substance to waste water from a wet ozone-oxidizing deodorizer. CONSTITUTION:Sodium hypochlorite 21 is added to overflowing waste water 14 having COD of about 50-150ppm, and the condition that the liquid is in an oxidative state is confirmed by use of an ORP meter 29. Since the pH value of the overflowing water is low, caustic soda 30 is added to hold the water in an alkaline state, while controlling its addition amount with a pH meter 41. Thereafter, the water is introduced into a neutralizing vessel 32, where the water is adjusted at pH about 6-8. In this way, most of malodorous substances as COD components are decomposed by oxidation. Sodium thiosulfate or the like is then added to the water in a reducing vessel 33, to decompose the hypochlorite. Thereafter, the water is drained as purified water 34, whose COD value is extremely lowered, outside the system.

Abstract: PURPOSE:To obtain a beta-pH curve with the simplicity same as the ordinary titration operation by self-recording a buffer power beta with respect to pH after it is determined by an electric treatment of response of a pH electrode in a sample liquid with the titration of a strong acid or a strong base CONSTITUTION:A sample liquid 4 containing ionogen is titrated with a strong acid or a strong base For example, a voltage output of a pH meter equipped with a glass electrode 2 and a reference electrode 3 is amplified with an amplifier and an output of the time variation dE/dt thereof is obtained with a differentiation circuit After the amplification of the output, an output is obtained with multiplying/dividing module in proportion to an inverse number dt/dE thereof As the value dE is proportional to dpH, dt/dE is proportional to a dt/dpH The output thus obtained is inputted to the axis Y of a XY recorder while the output of the pH meter is inputted to the axis X thereof as intact In this manner, a relation curve between a buffer power beta and the pH is obtained as expressed by beta=dB/d'pH (beta represents the concentration with addition of a strong alkali)

Abstract: Publisher Summary This chapter describes secondary ion movements and its measurement in Halobacterium halobium. Recording of concentration changes of protons, potassium, and other ions in the suspending basal salt medium can be carried out in a thermostated glass vessel. One of a variety of commercially available pH meters connected to an appropriate recorder can be used, but recordings from the pH electrode should be tested against possible light artifacts and salt errors. For potassium measurements, the highly K + -selective electrode IS 561-K + (Philips) is often used plugged into a PHM 64 research pH meter. The electrode must be shielded against light, and noise and drift problems are greatly reduced if the reference electrode is placed externally in basal salt solution and connected via a basal salt–agar bridge to the reaction vessel. The reaction mixture should be stirred to reduce unstirred layer effects and nonuniform irradiation. Intracellular ion concentrations in collected samples can be determined by atomic absorption spectroscopy or flame photometry. In addition, radioactive isotopes may be used to determine both ion transport processes and the fraction of extracellular space to total pellet volume.

Abstract: The premeabilities of planar lipid bilayer (egg phosphatidylcholine-decane) membranes to butyric and formic acids were measured by tracer and pH electrode techniques. The purposes of the study were (a) to establish criteria for the applicability of each method and (b) to resolve a discrepancy between previously published permeabilities determined using the different techniques. Tracer fluxes of butyric acid were measured at several concentrations and pH's. Under symmetrical conditions the one-way flux of butyric acid(J) is described by 1/J = 1/Pul ([HA] + [A-]) + 1/Pm([HA]), where Pul and Pm are the unstirred layer and membrane permeability coefficients. Pm determined in this manner is 950 x 10(4) cm s-1. Published values for the butyric acid permeability for egg phosphatidylcholine-decane bilayers are 11.5 x 10(-4) (Wolosin and Ginsburg, 1975) and 640 x 10(-4) cm s-1 (Orbach and Finkelstein, 1980). Wolosin and Ginsburg measured net fluxes from a solution of pH = Pka into an unbuffered solution containing a pH electrode. Orbach and Finkelstein measured tracers fluxes under symmetrical conditions at pH 7.4. We reproduced the results of Wolosin and Ginsburg and showed that their apparently low Pm was caused by unstirred layer effects in their poorly buffered solutions. The permeability to formic acid (pKa = 3.75) measured by both tracer and pH electrode techniques was approximately 10(-2) cm s-1. However, if pm greater than Pul, the pH electrode technique cannot be used for measuring the permeabilities of weak acids with pKa's greater than approximately 4.

Abstract: The relationship between the decrease in intramyocardial extracellular pH and the degree of stenosis of the left anterior descending (LAD) coronary artery was studied in eight dogs pretreated with propranolol. Intramyocardial pH was measured with a miniature glass pH electrode and with a new photometric pH probe that uses fiber-optic filaments to measure the color change of an indicator substance in a small permeable chamber. The LAD was cannulated and perfused from the axillary artery. Cannula flow was measured with an electromagnetic flow probe, and regional myocardial blood flow (RMBF) was measured with radioactive microspheres before and at the end of a period of critical stenosis, 2/3 reduction of flow, or total occlusion of the LAD cannula. In the region of the glass electrode, the mean RMBF (+/-SE) decreased by 16.3 +/- 3.3, 52.7 +/- 7.3, and 84.8 +/- 6.5% during the three levels of stenosis, and the pH correspondingly decreased by 0.05 +/- 0.01, 0.29 +/- 0.10, and 0.94 +/- 0.17 units. In the region of the photometric probe, the RMBF decreased 19.1 +/- 1.3, 47.2 +/- 6.7, and 84.3 +/- 6.0%, and the pH decreased by 0.05 +/- 0.02, 0.14 +/- 0.04, and 0.76 +/- 0.18 units. There was no statistically significant difference between the two types of pH sensor.