In connection to the preceding 1-st report, this paper deals in detail with the effect of foreign substances on the color development, that of sodium chloride or calcium chloride on the relation between boron concentration and color intensity, and also that of the concentration of an aqueous ethanol used to extract the colored product on the color intensity and stability of a resulting colored solution.
The results are as follows: the presence of 28m.eq. of hydrofluoric, 1.5m.eq. of hydrochloric, or 3.16m.eq. of oxalic acid in 3ml portions of a boron solution assigned to the color development is permissible; the presence of 0.22.0m.eq. of sodium chloride results in a fairly constant low color intensity while that of calcium chloride or oxide intensifies the color; the presence of any other possible foreign substances should be avoided; the addition of ethanol or methanol to the assigned portions of a boron solution greatly interferes with the color development; the most suitable extractant for the reaction product is 95% ethanol; and Beefs law is held up to 0.125μg. of boron per ml when the color development has been done in the presence of 1.00m.eq. of calcium chloride.
The author recommends the following precedure to determine 0.052.50μg. of boron expecting a standard deviation less than 3% for more than 1μg. of boron: 24ml of a sample solution containing 1.00m.eq. of calcium chloride is taken in a platinum dish and subjected to the color development as described in the 1-st report.
Resulting colored product is extracted with exact 20ml of 95% ethanol. The extract is centrifuged and, within 2 hours, its absorbancy is measured in a 1cm cell against the ethanol. When a sample solution is a methanolic solution obtained by a methyl borate distillation, the methanol is driven off in the presence of calcium hydroxide. The residue is dissolved with 24ml of water containing about 1ml of 1N hydrochloric acid and is ready for the color development.
Purification of curcumin by recrystallization is also referred to.

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In relation to the preliminary separation of boron to be determined with a curcumin-oxalic acid reagent, the volatilization loss of boron from a borate solution by evaporation and fuming with sulfuric acid, and that from a methanolic solution by evaporation have been studied in detail. It has been found that the evaporation loss is prevented completely by the addition of orthophosphoric acid to an acid solution of borate, and that the presence of water more than 43% is required to prevent the volatilization loss when a methanolic solution is evaporated in the presence of calcium hydroxide.
Comparison of boron recoveries between several methods of distillation as methyl borate whereby hydrochloric, sufuric, phosphoric and picric acids have been used shows that double distillation with 15ml portions of methanol is required for the complete recovery except in the case of phosphoric acid wherein triple distillation is required. A distilling apparatus provided with an inlet for carrier gas has been designed for its convenient use.
The author recommends the following procedure to separate whole of 0.052.50μg. of boron associated with large amounts of sulfuric, hydrochloric and nitric acids: to an appropriate amounts of a sample solution placed in a transparent quartz ware, 0.5ml of concentrated phosphoric acid and, if necessary, 12ml of concentrated sulfuric acid are added. The solution is evaporated to about 2ml or fumed with sulfuric acid. It is transfered in a distilling apparatus and the boron is distilled into 50ml of water containing 1m. eq. of calcium hydroxide by triple distillation with 15ml portions of methanol. The distillate is evaporated to dryness on a water bath and the boron is determined as described in the preceding report {M. Miyamoto, this Journal, 11, 635, 115 (1962)}.
Methods of preparation also have been studied to obtain boron-free inorganic acids, calcium oxide and alcohols.

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It was ascertained by the derivation from the equation of theoretical plate that when a larger amount of substance is treated with the preparative gas chromatograph, not only a column with large area must be used but also the sample should be evaporated as soon as it is introduced into the path of carrier gas. And an evaporating chamber of large volume (ca. 200ml) was constructed. The results of extensive experiments on this apparatus showed that a large amount of sample (ca. 5ml) could be introduced with no trouble, provided that the temperature of evaporating chamber was quite high and the flow rate of carrier gas was large enough.
Also it was noted experimentally that when a column of large diameter (ca. 35mm) was used the separating power of the column is lowered on account of heterogeneous distribution of packed particles of various sizes. For an improvement of this a new heart-rod column of large diameter was designed, whereby the separating power was kept as large as that in a column of small diameter even when the packed particles were of various sizes.

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The electrophoresing migration substances on the filter paper as well as the evolution of heat by electrophoresing current and accompanying evaporation of elecrtolyte and capillary flow of electrolyte toward the center was compared on an open-strip in a horizontal position and on a filter strip sandwiched between two glass plates in a closed system with cooling. The openstrip type showed considerable heat evolution and the direction, pattern, and velocity of migration were much influenced. The reproducibility was poor and it was quite difficult to keep high voltages in the electrophoresis. The sandwich method was less influenced by these factors, giving good reproducibility and an availability for high voltage. A sandwich-type filter paper deck for high voltage was devised by the author, and the reproducibility of the measurements was illustrated in a sigle monograph.

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In order to establish the method of analysis of Bisphenol A (I) and impurities in it, the application of gas chromatographic technique has been studied.
Di- and tri-nuclear phenols were partially decomposed when C-22 firebrick, Chromosorb P and W (acid washed) and others were used as column support at high temperature. These phenols could be determined quantitatively without decomposition by using column containing 10 weight% up of Apiezon grease L (AL) as a stationary phase on Celite 545 (acid washed) below the decompositon temperature.
For the separation of di-nuclear phenols[(1), 2-(2-hydroxyphenyl)-2-(4-hydroxyphenyl)propane(II), and 4, 4'-hydroxyphenyl-2, 2, 4-trimethylchroman (III)], a mixed column (3mm×40cm) was used at 220°C. It contained 20 weight% of AL mixed with polycarbonate (10 to 15 weight% to AL) as a stationary phase on Celite 545. The flow rate of helium as the carrier gas was maintained 100 ml per minute. In the case of the trace analysis of impurities in. I, these phenols exclusive of I could be determined quantitatively using p-phenylphenol as an internal standard, after extraction with xylene at its boiling point.
Tri-nuclear phenols [2, 4-bis(α, α-dimethyl-4-hydroxybenzyl)phenol(IV)] in I could be determine quantitatively using 2, 6-bis(2'-hydroxy-3'-tert-butyl-5'-methylbenzy1)-4-methylphenol (Antioxidant-80) as an internal standard. The column (2.5mm×40cm) contained 10 weight% AL as a stationary phase on Celite 545, and its temperature was 300°C. The optimum flow rate of helium as the carrier gas was 30ml per minute.
Determination of IV was not disturbed by a presence of a large quantity of I.

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100mg of sample (mixture of calcium oxalatemonohydrate and magnesium oxalate dihydrate) was analyzed with a differential thermal analyser under heating rate of 4°C/min. DTA curve exhibited four peaks, including a peak of endothermic reaction with liberation of crystalling water from the two compounds (220°C, peak I), another peak of exothermic reaction with liberation and oxidation of CO from calcium oxalate (480°C, peak II), another peak of endothermic reaction with liberation of CO and CO₂ from magnesium oxalate (510°C, peak III), and the last peak of endothermic reaction with liberation of CO₂ from calcium compound (850°C, peak IV).
Determination of calcium was run by an analysis of the relationship between the ratio of peak area (peak IV/peak I or peak IV/peak III) and weight percentage of calcium oxalate. That of magnesium was run by the same method as calcium, where the ratio of peak area to be used was peak III/ peak I or peak III/peak IV. Ten to 80% of calcium oxatate in magnesium oxalate or the reverse was determined within -7% error. An internal standard method with KH-phthalate was also studied.

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A rapid polarographic method was studied for determining terephthalaldehydic acid (TAA) in terephthalic acid. It was found that TAA in alkaline solution was reducible at the dropping mercury electrode. The polarographic waves of TAA consisted of two steps; half-wave potential for the 1st wave was -1.30 volt vs. S.C.E. The halfwave potential of 2nd wave was shifted from -1.68 to -1.44 volt with the increase of alkaline concentration. The total wave height was kept constant unless the decomposition of TAA was accelerated by the increase of alkaline concentration. The decomposition of TAA in 0.2M NaOH at room temperature could be neglected within about an hour. The presence of terephthalic acid, even ten thousand times as much as the amount of TAA, had no influencs on both the half-wave potential and the wave height. The limit of detection for TAA was 10^-6M, although the determination was governed by the solubility of terephthalic acid in alkaline solution. The optimum region was from a few to 0.01% by weight. The procedure was that the sample was dissolved in 0.15M NaOH, and the solution was put under the polarograph. The time required was only 20 minutes.

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Manganese in iron, steel and iron ore was determined polarographically, by using a supporting electrolyte of 0.5M triethanolamine with 1M sodium hydroxide, whereby following facts were found. In the presence of chromium(III) in triethanolamine-sodium hydroxide solution, manganese(III) triethanolamine was decomposed and manganese was precipitated. This was prevented by preliminary oxidation of chromium(III) to chromium(VI). Addition of potassium cyanide to this supporting electrolyte had a profit of diminishing the copper wave, which appeared close to that of manganese(III) and interfered. However, potassium cyanide acted slowly on manganese(III) to reduce it, and an addition of its large amount lowered the reproducibility of manganese wave. This was avoided by the use of cyanide concentration less than ca. 0.02M.

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Manganese in iron, steel and iron ore was determined polarographically, by using a supporting electrolyte of 0.5M triethanolamine with 1M sodium hydroxide, whereby following facts were found. In the presence of chromium(III) in triethanolamine-sodium hydroxide solution, manganese(III) triethanolamine was decomposed and manganese was precipitated. This was prevented by preliminary oxidation of chromium(III) to chromium(VI). Addition of potassium cyanide to this supporting electrolyte had a profit of diminishing the copper wave, which appeared close to that of manganese(III) and interfered. However, potassium cyanide acted slowly on manganese(III) to reduce it, and an addition of its large amount lowered the reproducibility of manganese wave. This was avoided by the use of cyanide concentration less than ca. 0.02M.

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The long period fluctuation in fluorescent X-ray analysis is more significant but smaller in its extent than the daily variation in respective measurements, so that a highly accurate correction is necessary to avoid overaction.
On the other hand, any complicated and expensive method of correction is not practical for routine work in plant operation. The authors have found from statistical investigation that this long period fluctuation arose in definite direction and value regardless of wavelength or intensity of X-ray, and have recommended a simple method for controlling the fluctuation. A reference sample standard with standard composition is analyzed at a definite hour every day, whereby any abnormality of the apparatus is checked and the daily variation is known from the sum of intensities for each component.
By this method, the variation of chromium and nickel X-ray intensities in various stainless steels was controlled for five months within a range of daily variation and this was confirmed to be an accurate correction method applicable to routine analysis.

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When the extraction is carried out in the system of thiocyanate-TBP- diluent, thorium, rare earth elements and scandium can be easily separated by selecting suitable diluents. For example, thorium (1g) can be separated from small amounts of rare earth elements (10μg) in the system of 15% TBP-carbon tetrachloride/2M ammonium thiocyanate. Scandium (100μg) can be separated from thorium (400mg) using the extraction system of 10% TBP-chloroform/1M ammonium thiocyanate.
The back extraction of the elements extracted into the organic phase is accomplished by 13N hydrochloric acid or nitric acid.

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Colorimetric determination of inorganic phosphate in micro amounts of human urine by molybdenum blue method was studied.
Ammonium molybdate solution was mixed with Bi(NO₃)₃ nitric acid solution and as reducing reagent, 1-amino-2-naphthol-4-sulfonic acid, Na₂SO₃ and Na₂S₂O₅ were dissolved together. Those reagents remained effective for more than several months. The molybdenum blue developed was very stable and the intensity did not change at least for 2 hours.
The recommended analytical procedure was as follows: 0.0025ml of urine adjusted to pH5.4 was taken by the use of a micro pipette. One ml of distilled water and 2ml of ammonium molybdate solution were added and shaken vigorously. Being stood for about 5 minutes, 10ml of distilled water and 0.5ml of the reducing reagent were added and absorbance was measured after 5 minutes at 730mμ by a 10mm cell. The most suitable reaction temperature was 2035°C.

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[in Japanese]

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[in Japanese]

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[in Japanese]

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