Sodium Citrate Mixture Research Articles

Performance and mechanism of a composite scaling–corrosion inhibitor used in seawater: 10-Methylacridinium iodide and sodium citrate

An environment-friendly scaling–corrosion inhibitor composed of 10-methylacridinium iodide (MAI) and sodium citrate (SC) was developed, whose scale inhibition performance were studied through weight loss, electrochemical techniques, static tests and surface analysis techniques (SEM, SECM, XPS, XRD). The optimum mass ratio of MAI and SC corrosion inhibition was found to be 1:2, and the optimum mass ratio of scale inhibition was 1:3. The experimental results showed that MAI–SC mixture as mixed-type scaling–corrosion inhibitor with excellent corrosion (ηw = 92.7%) and scale inhibition performance (ηCa = 98.3%). The electrochemical stability of the inhibitor film was investigated by chronoamperometry (CA). SEM and XRD simulations indicated that the MAI–SC mixture inhibitor can distort and disperse the crystal lattice of calcium carbonate without forming scale, and it plays a dominant role in the inhibition of calcite (110) surface growth. The structure-activity relationship between the molecule structure of the MAI–SC mixture and its scale–corrosion inhibition performance was discussed based on the quantum chemistry calculation.

Sequential SERS determination of aspirin and vitamin C using in situ laser-induced photochemical silver substrate synthesis in a moving flow cell.

In this contribution, the utility of sequential injection analysis in combination with surface-enhanced Raman spectroscopy (SERS) as a detection technique was investigated for simultaneous determination of aspirin and vitamin C in their pharmaceutical dosage forms and in spiked urine samples. The silver substrate was synthesized in situ by laser-induced photochemical procedure. By focusing the laser on a flow cell at 1ml/min of continuous flow of 0.5mM silver nitrate and 5mM sodium citrate mixture, an active silver spot on the inner wall of the flow cell was prepared in a few seconds. The whole setup is fully computer controlled using ATLAS software to combine the two techniques. The system allows sequential determination of aspirin concentrations ranging from 100 to 500ng/ml and vitamin C concentrations between 10 and 110ng/ml with good precision of relative standard deviations (RSDs) of 0.85 and 1.7%, respectively. A comparison of these results with those of the reported procedures showed excellent results compared with t and F values, indicating good accuracy and precision. The detection limits were 32 and 3ng/ml for aspirin and vitamin C, respectively.

In situ laser-induced photochemical silver substrate synthesis and sequential SERS detection in a flow cell

A new, simple, and effective approach for multianalyte sequential surface-enhanced Raman scattering (SERS) detection in a flow cell is reported. The silver substrate was prepared in situ by laser-induced photochemical synthesis. By focusing the laser on the 320 μm inner diameter glass capillary at 0.5 ml/min continuous flow of 1 mM silver nitrate and 10 mM sodium citrate mixture, a SERS active silver spot on the inner wall of the glass capillary was prepared in a few seconds. The test analytes, dacarbazine, 4-(2-pyridylazo)resorcinol (PAR) complex with Cu(II), and amoxicillin, were sequentially injected into the flow cell. Each analyte was adsorbed to the silver surface, enabling the recording of high intensity SERS spectra even at 2 s integration times, followed by desorption from the silver surface and being washed away from the capillary. Before and after each analyte passed the detection window, citrate background spectra were recorded, and thus, no "memory effects" perturbed the SERS detection. A good reproducibility of the SERS spectra obtained under flow conditions was observed. The laser-induced photochemically synthesized silver substrate enables high Raman enhancement, is characterized by fast preparation with a high success rate, and represents a valuable alternative for silver colloids as SERS substrate in flow approaches.

The effects of citric acid on phytate-phosphorus utilization in young chicks and pigs.

Several bioassays were conducted with young chicks and pigs fed phosphorus (P)-deficient corn-soybean meal diets. With diets for chicks containing .62% Ca and .42% P (.10% available P), graded doses of a citric acid + sodium citrate (1:1, wt:wt) mixture (0, 1, 2, 4, or 6% of diet) resulted in linear (P < .01) increases in both weight gain and tibia ash. Relative to chicks fed no citric acid, tibia ash (%) and weight gain (g/d) were increased by 43 and 22%, respectively, in chicks fed 6% citric acid. Additional chick trials showed that 6% citric acid alone or sodium citrate alone was as efficacious as the citric acid + sodium citrate mixture and that 1,450 U/kg of phytase produced a positive response in bone ash and weight gain in chicks fed a diet containing 6% citrate. Varying the Ca:available P ratio with and without citrate supplementation indicated that citric acid primarily affected phytate-P utilization, not Ca, in chicks. Moreover, chicks did not respond to citrate supplementation when fed a P-deficient (.13% available P), phytate-free casein-dextrose diet. Young pigs averaging 10 to 11 kg also were used to evaluate citric acid efficacy in two experiments. A P-deficient corn-soybean meal basal diet was used to construct five treatment diets that contained 1) no additive, 2) 3% citric acid, 3) 6% citric acid, 4) 1,450 U/kg phytase, and 5) 6% citric acid + 1,450 U/kg phytase. Phytase supplementation increased (P < .01) weight gain, gain:feed, and metatarsal ash, whereas citric acid addition increased only gain:feed (P < .05) and metatarsal ash (P < .08). A subsequent 22-d pig experiment was conducted to evaluate the effect of lower levels of citric acid (0, 1, 2, or 3%) or 1,450 U/kg phytase addition to a P-deficient corn-soybean meal diet. Phytase supplementation improved (P < .01) all criteria measured. Weight gain and gain:feed data suggested a response to citric acid addition, but this was not supported by fibula ash results (P > .10). The positive responses to phytase were much greater than those to citric acid in both pig experiments. Thus, dietary citric acid effectively improved phytate P utilization in chicks but had a much smaller effect in pigs.

Acid aspiration prophylaxis in Australian obstetric hospitals--a survey.

During 1987 a confidential survey of all hospitals in Australia providing obstetric services was undertaken to determine the antacid medications used routinely as prophylaxis against acid aspiration pneumonitis. Of the 567 hospitals surveyed, 379 (67%) responded. Of these, 243 hospitals provide an obstetric service which includes caesarean section, and 67% of these perform less than 500 deliveries per annum. Aspiration prophylaxis during labour was used in 22.4% of responding hospitals. Prior to elective caesarean section, 11.5% used no prophylaxis, and 39.4% used particulate antacids such as magnesium trisilicate mixture (33.3%) or Mylanta (6.1%). Sodium citrate mixture was the most popular therapy (37%). Results were similar in the emergency caesarean section group. The use of cimetidine or ranitidine was uncommon in all groups. Results of this survey suggest marked differences in attitudes towards acid aspiration prophylaxis between Australian and British obstetric anaesthetic practices.

Comparison of the Prophylactic Use of Magnesium Trisilicate Mixture B.P.C., Sodium Citrate Mixture or Cimetidine in Obstetrics

The effects of magnesium trisilicate mixture B.P.C., sodium citrate mixture or cimetidine on gastric pH and aspirated gastric volumes were compared in 78 obstetric patients during elective (a), or emergency (b) surgery. Magnesium trisilicate mixture B.P.C. was associated with the most alkaline values of gastric pH (mean (a) 7.9, (b) 7.3; range 2.9–9.1). Sodium citrate 0.3 mol litre-1 mixture resulted in the narrowest range of pH values of gastric contents (mean (a) 5.4, (b) 5.9; range 3.9–7.7). The ranges of aspirated gastric volumes were wide with both antacid regimens (magnesium trisilicate 12–172 ml, sodium citrate9–290ml). Cimetidine increased gastric pH to greater than 2.5 in 82% of patients (mean (a) 6.2, (b) 5.0; range 1.6–7.3), and was associated with significantly smaller volumes of aspirated gastric contents (range 0.5–44 ml). When gastric pH and volume were considered together, the groups of patients who received cimetidine were found to be closest to the defined safe limits, of pH ≥ 2.5 and volume ≤ 25 ml.

Comparison of the Prophylactic Use of Magnesium Trisilicate Mixture B.P.C., Sodium Citrate Mixture or Cimetidine in Obstetrics

The effects of magnesium trisilicate mixture B.P.C., sodium citrate mixture or cimetidine on gastric pH and aspirated gastric volumes were compared in 78 obstetric patients during elective (a), or emergency (b) surgery. Magnesium trisilicate mixture B.P.C. was associated with the most alkaline values of gastric pH (mean (a) 7.9, (b) 7.3; range 2.9–9.1). Sodium citrate 0.3 mol litre-1 mixture resulted in the narrowest range of pH values of gastric contents (mean (a) 5.4, (b) 5.9; range 3.9–7.7). The ranges of aspirated gastric volumes were wide with both antacid regimens (magnesium trisilicate 12–172 ml, sodium citrate9–290ml). Cimetidine increased gastric pH to greater than 2.5 in 82% of patients (mean (a) 6.2, (b) 5.0; range 1.6–7.3), and was associated with significantly smaller volumes of aspirated gastric contents (range 0.5–44 ml). When gastric pH and volume were considered together, the groups of patients who received cimetidine were found to be closest to the defined safe limits, of pH ≥ 2.5 and volume ≤ 25 ml.

COMPARISON OF THE PROPHYLACTIC USE OF MAGNESIUM TRISILICATE MIXTURE B.P.C., SODIUM CITRATE MIXTURE OR CIMETIDINE IN OBSTETRICS

The effects of magnesium trisilicate mixture B.P.C., sodium citrate mixture or cimetidine on gastric pH and aspirated gastric volumes were compared in 78 obstetric patients during elective (a), or emergency (b) surgery. Magnesium trisilicate mixture B.P.C. was associated with the most alkaline values of gastric pH (mean (a) 7.9, (b) 7.3; range 2.9-9.1). Sodium citrate 0.3 mol litre-1 mixture resulted in the narrowest range of pH values of gastric contents (mean (a) 5.4, (b) 5.9; range 3.9-7.7). The ranges of aspirated gastric volumes were wide with both antacid regimens (magnesium trisilicate 12-172 ml, sodium citrate 9-290 ml). Cimetidine increased gastric pH to greater than 2.5 in 82% of patients (mean (a) 6.2, (b) 5.0; range 1.6-7.3), and was associated with significantly smaller volumes of aspirated gastric contents (range 0.5-44 ml). When gastric pH and volume were considered together, the groups of patients who received cimetidine were found to be closest to the defined "safe limits", of pH greater than 2.5 and volume less than 25 ml.

Comparison of the Prophylactic Use of Magnesium Trisilicate Mixture B.P.C., Sodium Citrate Mixture or Cimetidine in Obstetrics

Comparison of the Prophylactic Use of Magnesium Trisilicate Mixture B.P.C., Sodium Citrate Mixture or Cimetidine in Obstetrics

PULMONARY ACID ASPIRATION SYNDROME

The gastric contents of three groups of patients were aspirated at the beginning and end of anaesthesia. There were 62 prepared patients, 28 emergency patients untreated and 69 prepared patients who were given 15 ml of 0.3 M sodium citrate mixture at the time of premedication. In approximately 50% of both emergency and prepared patients pH of gastric contents initially suggested the risk of developing acid aspiration syndrome, had inhalation occured. The proportion of untreated patients in whom more than 40 ml of gastric contents was present at induction and when the tracheal tube was removed were 13% and 31% respectively. The risks were greater in those undergoing upper abdominal operations. Sodium citrate, as used in this study, was shown to be an ineffective antacid. The use of Mist. magnesium trisilicate B.P. as preoperative antacid is urged strongly.

PULMONARY ACID ASPIRATION SYNDROME: SHOULD PROPHYLAXIS BE ROUTINE?

The gastric contents of three groups of patients were aspirated at the beginning and end of anaesthesia. There were 62 prepared patients, 28 emergency patients untreated and 69 prepared patients who were given 15 ml of 0.3 M sodium citrate mixture at the time of premedication. In approximately 50% of both emergency and prepared patients pH of gastric contents initially suggested the risk of developing acid aspiration syndrome, had inhalation occurred. The proportion of untreated patients in whom more than 40 ml of gastric contents was present at induction and when the tracheal tube was removed were 13% and 31% respectively. The risks were greater in those undergoing upper abdominal operations. Sodium citrate, as used in this study, was shown to be an ineffective antacid. The use of Mist. magnesium trisilicate B.P. as preoperative antacid is urged strongly.

Effects of fixation and demineralization on the intensity of autoradiographic labelling over the periodontal ligament of the mouse incisor after administration of [ 3H]-proline

The effect of different histological procedures on the autoradiographic grain count over the periodontal ligament was studied quantitatively in autoradiographs made eight hours after administration of [ 3H]-proline. The lower jaws of 9 mice were fixed in Bouin's fixative, in 10 per cent formalin or in Carnoy's fluid and were demineralized either in EDTA or in a mixture of formic acid and sodium citrate. With Bouin's fixative, higher grain densitites were obtained than with formalin or Carnoy's fluid. Liquid scintillation counting revealed that in formalin traces of non-dialyzable tritiated substances were present. A greater loss of non-dialyzable radioactivity occurred during the demineralization of the jaws fixed in Carnoy's fluid particularly when this was performed in a formic acid and sodium citrate mixture. For the latter mandibles, autoradiography revealed a low grain density over the periodontal ligament while the relative shrinkage of the tissue appeared to be high. Biochemical analysis of the dialysates of the formic acid and sodium citrate mixtures from these mandibles showed that part of the radioactivity lost was bound to collagen.