Determination of trace organic dicarboxylic acids and amines by ion-chromatography.

Retention times for various species in separator columns packed with Zipax SAX, Vydac SC, and MicroPak AX-10 anion-exchange resins were compared with those obtained with Dionex separator column for anions. The MicroPak column was found to separate organic dicarboxylic acids, and the logarithm of the retention time of the acids of a homologous series was found to bear a simple relationship to the number of methylene groups between the carboxylic groups. A modified column system, consisting of a post-separator column packed with Vydac CX cation-exchange resin placed between a Dionex separator column for cations and a suppressor column, was able to separate a nine-component mixture of Na(+), K(+), NH(4)(+), methylamine, ethylamine, propylamine, butylamine, dimethylamine and trimethylamine, a separation that is not possible with any other current column system.

Solvent extraction and photometric determination of molybdenum (VI) with 2-aminobenzenethiol.

A new extractive photometric method is described for estimation of molybdenum with 2-aminobenzenethiol. The green complex in chloroform has its absorbance maximum at 700 nm and is stable for 2 hr when extracted from a solution of optimum pH range 1.4-2.8. The extraction is quantitative. The sensitivity is 0.0075 microg cm (2). Beer's law is obeyed over the range 0.25-10 ppm with optimum range 0.5-4.5 ppm. The molar absorptivity is 7.08 x 10(4) 1.mole(-1). cm(-1). The overall stability constant is 2.0 x 10(8) at 25 +/- 0.1 degrees.

2,2'-Diaminodiphenyldisulphide-a new sensitive spectrophotometric reagent for platinum.

2,2'-Diaminodiphenyldisulphide is a highly sensitive platinum chromogen. Platinum(IV) forms a complex with it in 50% aqueous ethanol at pH 5.0-6.0, having maximum absorption at 725 nm. The molar absorptivity of the complex is 5.48 x 10(4)1.mole(-1).cm(-1) at 725nm and the sensitivity is 0.0035 mug/cm(2). The colour system obeys Beer's law from 0.25 to 5 ppm with optimum concentration range 0.75-4 ppm of platinum. The relative error is 2.7%. The metal to reagent ratio is 1:2, and the stepwise formation constants K(1) and K(2) are 5.6 x 10(4) and 1.96 x 10(4) respectively.

Spectrophotometric estimation of molybdenum with disodiom cis-1,2-dicyanoetfaylene-1,2-dithiolate.

A rapid spectrophotometnc method is described for estimation of molybdenum by use of the molybdenum-dicyanoethytene dithiolate complex. The bright green complex has its absorption maximum at 665 nm and in 50% aqueous acetonitrilc is stable for several days at 3M hydrochloric add concentration, The estimation is more sélective if longer wavelengths and high acidity are used. Beer's law is obeyed over the range 1-16 ppm molybdenum, optimum range 4-16 ppm. The overall formation constant Of the complex with metal to ligand ratio of 1:4 is 5 +/- 2 x 10(18). The molar absorptivity is 5.05 x 10(3) l.mole(-1).cm(-1).

Amperometric titration of mercury with a stationary platinum electrode in stirred solutions.

Amperometric titration of mercury (in the range of 0-4 to 3.5 mg) has been carried out with 2-mercaptobenzoxazole with a stationary electrode in stirred solution in a sodium acetate-acetic acid medium.

Extraction of vanadium(V) chelates with N-benzohydroxamic acid (BHA) and ammonium thiocyanate and its application in steel and rock analyses.

A mixed-ligand complex of vanadium(V) with N-benzohydroxamic acid and thiocyanate formed at various acidities can be extracted into methyl isobutyl ketone, and used for photometric determination of trace amounts of vanadium in materials such as alloy steels and rocks. The absorption maximum of the violet mixed-ligand complex is at 535 nm. The values for the simple complex are 505 nm and molar absorptivity 7.4 x 10(3)l.mole(-1).cm(-1).

Chloroaceto hydroxamic acid as antitumor agent against Ehrlich ascites carcinoma in mice.

In vivo cell growth inhibition of Ehrlich ascites carcinoma (EAC) has been evaluated with chloroacetohydroxamic acid, (CHA), having -CH2 Cl, for the -NH2 group of hydroxyurea (HU). The inhibitory character of CHA against EAC in mice model has been found to be comparable with that of HU. Cell growth inhibition by CHA is accompanied by inhibitions of DNA and protein synthesis of the treated cells. The transplantability of EAC cells treated with a single dose of (100 mg/kg) CHA is found to be reduced. Enhanced intraperitoneal macrophage is observed in normal mice following CHA (100 mg/kg) treatment. Deviations of hematological parameters and alkaline phosphatase (ALKP) activity consequent to tumor growth are found to be recovered in tumor bearing mice treated with CHA. All these studies suggest the importance of CHA for further trial as a potent antitumor agent.

Antitumor properties of boron complexes with hydroxy biguanide and salicyl hydroxamic acid against Ehrlich ascites carcinoma.

A new derivative of hydroxamic acid, hydroxy biguanido hydrochloride monohydrate and its boron derivative, dihydroxy-oxybiguanido boron (III) hydrochloride monohydrate were synthesized. Another boron compound, hydroxo-salicyl-hydroxamato boron (III) was synthesized from known salicyl hydroxamic acid. Antitumor properties of all the compounds evaluated against Ehrlich ascites carcinoma in mice show enhanced survival time when boron is incorporated in the compounds. Hematological parameters, alkaline phosphatase in serum of the treated animals show minimum toxic effects after boron is coupled with their respective hydroxamic acids.

On the possible use of a new boron compound, hydroxysalicylhydroxamato boron(III), and ultrasound in the treatment of female mice bearing the Ehrlich ascites carcinoma cells.

The inhibitory effects of a new boron compound, hydroxy salicylhydroxamato boron (III) (SHB) and ultrasound of frequency 25 KHz (US) on the growth of ascites tumor in female Swiss mice were studied by monitoring the survival and the tumor growth in the treated tumor bearing mice and also the transplantability and the DNA synthesis in the treated tumor (Ehrlich ascites carcinoma) cells. While SHB alone produced a highly significant antitumor activity, US alone produced a small but significant effect. The combination of SHB and US produced significantly greater antitumor activity than SHB alone. The mechanisms of SHB and US actionary are discussed.

A new boron compound (guanidine biboric acid adduct) as an antitumour agent against Ehrlich ascites carcinoma in mice.

The inhibitory effects of a new boron compound of guanidine biboric acid adduct (GB) and guanidium chloride (L1) on the growth of ascites tumour in female Swiss mice were studied by monitoring the survival, tumour weight, tumour cell count, transplantability of Ehrlich ascites cells, precursor incorporation and the haematological parameters of the treated mice. 5-Fluorouracil, a known anticancer drug, was used as a positive control. The most important parameter was the survival time, which increased significantly when tumour-bearing mice were treated with the boron compound. Haematological parameters of the treated animals showed minimum toxic effects when boron was coupled with guanidine.

On the inhibitory activities of a new boron compound and ultrasound against the mouse ascites tumour.

The inhibitory effects of a new boron compound, dihydroxy (oxybiguanido) boron (III) hydrochloride monohydrate (HB), and ultrasound (US) of a frequency 25 kHz on the growth of ascites tumour in female Swiss mice were studied by monitoring the survival, weight of tumour-associated material, tumour cell count, serum alkaline phosphatase activity and the haematological parameters of the treated animals. 5-Fluorouracil (5-FU), a well-known anticancer agent, was used as positive control. While HB exhibited a very significant antitumour action, US alone produced a small but significant inhibitory effect. The combination of US with HB or 5-FU produced an extra antitumour action as compared to the actions of these chemicals used singly. The mechanisms of action of the new boron compound (HB) and US are discussed.