Sulphosalicylic acid

Determination of iron(III) in the presence of aluminium. Iron(III) (concentration ca 50 mg per 100 mL) can be determined in the presence of up to twice the amount of aluminium by photometric titration with EDTA in the presence of 5-sulphosalicylic acid (2 per cent aqueous solution) as indicator at pH 1.0 at a wavelength of 510 nm. The pH of a strongly acidic solution may be adjusted to the desired value with a concentrated solution of sodium acetate about 8-10 drops of the indicator solution are required. The spectrophotometric titration curve is of the form shown in Fig. 17.23. 

It has also been observed " that sulphosalicylic acid strongly catalyses autooxidation of Fe(II) at pH 6. A complex of the chelate, Fe(II) and molecular oxygen is believed to be formed and to break down. Ethylenediaminetetraacetic and its analogues behave similarly . 

The fast interaction of O2 with Fe(II)-cysteine complexes to give an oxygen adduct which rapidly undergoes one-electron breakdown to an Fe(III)-cysteine complex and -OJ has been examined by stopped-flow spectrophotometry at 570 nm . Subsequent decomposition of the Fe(IlI) complex to yield Fe(II) and the disulphide, cystine, was much slower. Both mono- and bis-complexes of Fe(Il) are involved and the reaction is first-order in both Fe(II) complex and O2 k (mono) = (5 +1) x 10 l.mole ksec" and k (bis) = (2 0.5) x lO l.mole . sec at 25 °C, corresponding to factors of 10 and 10 times faster than the analogous reactions with sulphosalicylic acid complexes of Fe(II), a feature attributed to Fe(ll)-S bonding in the cysteine complexes. ... 

Sulphosalicylic acid [5965-83-3] M 254.2, m 108-110". Crystd from water. Alternatively, it was converted to the monosodium salt which was crystd from water and washed with a little water, EtOH and then ethyl ether. The free acid was recovered by acidification. 

S04 2 Nucleosit GB ion exchange resin Sulphosalicylic acid Radio ion chromatography - [57]... 

Rare earths EDTA Alizarin red That pH 1.5-2.2 REE at pH 4.5 with sulphosalicylic acid and ascorbic acid [100]... 

The precipitation of aluminium hydroxide by solutions of sodium hydroxide and ammonia does not take place in the presence of tartaric acid, citric acid, sulphosalicylic acid, malic acid, sugars, and other organic hydroxy compounds, because of the formation of soluble complex salts. These organic substances must therefore be decomposed by gentle ignition or by evaporating with concentrated sulphuric or nitric acid before aluminium can be precipitated in the ordinary course of qualitative analysis. 

Table 7.1. Absorbance at 490 nm of aqueous solutions of Fe and Fe after derivatization with 5-sulphosalicylic acid.

Ethylenediamine (en), diethylenetriamine (dien), triethylene-tetramine (trien), and tetraethylenepentamine (tetren) form well characterized complexes with M(ii) ions. Such complexes have been the subjects of a number of NMR exchange studies. (299-303) studies have established the identities of [Cu(en)(H20)4], [Cu(en)2-(HjOjj], and complexes involving both en and sulphosalicylic acid ligands. (299-301) NMR studies have been made on aqueous solutions of [Ni(dien)(H20)3], [Ni(tren)(H20)2], and... 

Circularly polarized luminescence studies of Tb complexes with (—)-quinic acid, and of mixed-ligand complexes of the form Tb(MDL)2(HXCA) [where MDL = oxydiacetic, iminodiacetic, or 5-sulphosalicylic acid, HXCA = hydroxycarboxylic acid] and also of some nine-co-ordinate Eu complexes with oxydiacetate, dipicolinate. iminodiacetate, and N-(methylimino)diacetate... 

For diagnostic purposes, the following procedure of the Brdicka filtrate test is to be recommended. Add 0.4 ml of fresh blood serum to 1 ml 0.1 M KOH and allow to stand for 45 min. Precipitate the proteins at room temperature by the addition of 1 ml of 20% sulphosalicylic acid. After 10 min, filter the precipitate through a hard filter paper and add 0.5 ml of clear filtrate to 5 ml of buffered hexamino-cobalt(III) solution (10 M in 0.1 M NH4CI, 1 M NH3). Compare the increase in the height of the wave of the serum filtrate from the patients with the average height of that obtained from 10 or 20 normal humans. 

In weakly acidic media (pH 2.5-3) iron(III) forms a red-violet (1 1) complex with sulphosalicylic acid. Addition of fluoride partly decolorizes the solution owing to the formation of a stable iron-fluoride complex. A suitable pH is adjusted by means of a chloroacetate buffer. The method is recommended for determination of larger amounts of fluoride [42]. 

Ions of metals forming complexes with sulphosalicylic acid or fluoride, as well as anions which react with Fe(III), interfere in the determination of fluoride. Separation of fluoride by distillation prevents the interference of foreign ions. 

Sulphosalicylic acid, in solution. Dissolve in water 0.95 g of the hydrated reagent (or 0.82g of the anhydrous form) and dilute with water to 100 ml. 

Iron-sulphosalicylate reagent. Mix 20 ml of the sulphosalicylic acid solution with 40 ml of the Fe(lll) solution, and 2.8 ml of the NaOH solution. Dilute the solution with the chloroacetate buffer up to 100 ml and set aside for 5 h. The solution is stable within 10 days. Standard fluoride solution 1 mg/ml. Preparation as in Section 20.2.1. 

A very sensitive method for determination of Mn is based on its complex with sulphosalicylic acid, salicylfluorone, and CTA (e = 3.1-10 at 590 nm [48]. 

Thallium is extracted after oxidation to Tl(ni) with bromine, the excess of which is removed either by boiling or by reaction with phenol or sulphosalicylic acid. The thallium-Brilliant Green ion-associate is then formed by shaking the organic extract with a solution of Brilliant Green in 0.1-0.2 M HCl. The molar absorptivity of the complex in DIPE is 1.05-10 at 630 nm a = 0.51). 

Other organic reagents proposed for determination of uranium include octadecyl dithiocarbamate [126], Bromopyrogallol Red [18,127], Pyrogallol Red (e = 3.610 in the presence of CP) [128], benzoyltrifluoroacetone [129], sulphosalicylic acid [130], 2,4-dinitrosoresorcinol [131], and various hydrazones [132-134]. Uranium and thorium have been determined simultaneously by the second derivative method using 4-(2 -thiazolylazo-rezacetophenone) oxime [135-137]. Uranium was determined in the presence of Th by derivative spectrophotometry with the use of carminic acid [138]. Af-Hydroxy-V.AT-diphenylbenzamidine has been applied for determination of U (and Th) [139]. 

Spcctrophotometric studies on technetium and rhenium were carried out with K4[b e(C N)f,], sulphosalicylic acid, and a-picolinic acid using pcrtechnetatc or perrhe-nate as starting compounds and bismuth amalgam, SnCl2 or ascorbic acid as reducing agents 78j. 

Mondino A., Bongiovanni G., and Fumeros S. (1975) A new approach for obtaining total tryptophan recovery in plasma samples deproteinized with sulphosalicylic acid / Chromafogr. 104, 297-302. 

It did in fact cause Ostwald no surprise, but rather strengthened him in his ideas when it was found that the phase rule does not hold for the partial miscibility in the system gelatin + HoO + sulphosalicylic acid. 

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