Sulphonated monoamides having the formula: <FORM:0587271/III/1> wherein X and X1 are hydrogen or a cationic salt forming radical, R the residue of an aliphatic poly carboxylic acid, R1 an alkyl radical and R2 and R3 hydrogen, alkyl or a cationic salt forming radical are stated to have emulsifying, detergent and lubricating properties. As detergents they may be used alone or with soaps, sodium carbonate, tetrasodiumpyrophosphate, tetrasodium phosphate, sodium hexametaphosphate, abrasives, perfumes, borax and boric acid. As emulsifying agents they may be used alone or with glue, casein, starch, gums, fatty acids, fatty acid esters, fatty alcohols, pine oils, bentonite, clays and carbon black. They are also suitable for breaking petroleum emulsions such as are formed in storage tanks or in washing oils. As lubricants they may be used with animal and vegetable fats and hydrocarbon oils. N-octadecyl-N-1 : 2-dicarbomethoxyethyl disodiumsuccinamate and N-octadecyl-N - 1 : 2 - dicarboxyethyltetrasodiumsulphosuccinamate are sulphonated amides mentioned in the examples.ALSO:Compounds having the general formula <FORM:0587271/IV/1> (where X and X1 are hydrogen or a cationic salt-forming radical, R the residue of an aliphatic polycarboxylic acid, R1 an alkyl radical and R2 and R3 hydrogen, alkyl or a cationic salt-forming radical) are prepared by reacting an N-alkyl substituted aspartate with the anhydride of an unsaturated aliphatic polycarboxylic acid and sulphonating the resulting monoamide. The sulphonation is carried out by treatment with an alkali metal sulphite or with an alkali metal bisulphite after neutralization of the free carboxylic group of the monoamide or by treatment with sulphur dioxide and free alkali in the presence of water. Alternatively, the N-alkyl substituted aspartate may be reacted with a sulphonated aliphatic polycarboxylic anhydride or ester, followed in the former case by neutralization of the free carboxyl group, and in the latter by hydrolysis of the ester group by alkali. In the examples, dimethyl, diethyl, di-isopropyl and di-n-amyl N-octadecylaspartate, prepared by reacting the corresponding maleate with octadecylamine, are reacted with maleic anhydride and the products sulphonated with sodium sulphite. In addition, N-octadecyl-N-1.2-dicarboxyethyltetrasodiumsulphosuccinamate is prepared by reacting disodium-N-octadecyl aspartate with maleic anhydride. Wetting properties, foaming power, foam stability and calcium tolerance of solutions of the products are tabulated. Further starting materials mentioned are maleic, methyl and other alkyl and aryl substituted maleic anhydrides; itaconic, ethylitaconic and isopropylitaconic anhydrides; glutaconic, muconic and aconitic anhydrides and the anhydrides of the following sulphopolycarboxylic acids: sulphosuccinic acid, sulphomethyl, sulpho-isopropyl and sulphophenyl succinic acids; sulphoglutaric acid, sulphomethyl, and sulphooctyl glutaric acids, sulphopimelic, sulphosuberic, sulphosebacic and sulphotricarballylic acids. Dimethyl - N - octylaspartate, diethyl - N - decylaspartate, diamyl - N - tetradecylaspartate, diamyl-N-amylaspartate, diisopropyl-N-dodecylaspartate and dibutyl-N-octadecylaspartate are also specified. Solvents such as carbon tetrachloride, chloroform, acetone, tertiary butanol, benzene, toluene, dioxane and ethers may be used. The cation-active groups R2 and R3 in the general formula may be Na, K, NH4, Ba, Ca, Zn, Cd, Hg, morpholine or pyridine, whilst the groups X and X1 may be Na, K, Li, NH4, Ba, Ca, Zn, Cu, Hg, Cd, Mg, ethanolamine, morpholine, guanidine or pyridine. The products are stated to have wetting, foaming, dispersing and other surface-active properties. They may be used for dispersing pigments and dyes in the preparation of printing pastes. They may also be used as de-emulsifiers, particularly to resolve petroleum-water emulsions, and as levelling agents. They can be used as surface-active agents in ore dressing, cyanidation processes, dry cleaning, cleansing paper mill felts, extracting processes and in adhesives, wall paper paste, shoe polishes, cosmetics, electroplating baths, acid pickling baths and as lubricants alone or mixed with animal or vegetable fats. In the textile industry the products may be used as penetrating and carbonizing agents and in the leather industry for wetting out, soaking, de-liming and bating hides and in tanning, dyeing, sheet-liquoring and stuffing preparations. They may also be used in disinfectants, fungicides, horticultural sprays and in sprays designed to lay dust. They can be used as detergents either alone or with compound such as soaps, sodium carbonate, tetrasodium pyrophosphate, tetrasodium phosphate, sodium hexametaphosphate, bulking agents, abrasives, perfumes, borax, boric acid and other soap building agents. As emulsifying agents they can be used alone or with protective colloids such as glue, casein, starch gums and other emulsifying aids such as fatty acids, fatty acid esters, fatty alcohols, pine oils, bentonite, clays and carbon black. Anhydrides of sulphopolycarboxylic acids may be prepared by heating the acids in the presence of solvents such as toluene or o-dichlorbenzene and distilling off the water.ALSO:Sulphonated monoamides having the formula <FORM:0587271/II/1> wherein X and X1 are hydrogen or a cationic salt forming radical, R the residue of an aliphatic polycarboxylic acid, R1 an alkyl radical and R2 and R3 hydrogen, alkyl or a cationic salt-forming radical are stated to be useful as surface active agents in ore dressing, cyandation processes and in acid pickling baths. N-octadecyl-N-1:2 - dicarbomethoxyethyl - disodiumsuccinamate and N-octadecyl-N-1:2-dicarboxyethyltetrasodiumsulphosuccinamate are sulphonated amides mentioned in the examples.