these and other objects have been achieved through the use of cleaning solutions comprising sorbitol , edta salts , sodium or ammonium nitrate , and optionally , nitric acid and / or preferably a corrosion inhibitor . this composition is preferably prepared as a concentrate and then diluted for use . ethylene glycol is used in preparing the concentrate in order to render the concentrate storage stable for extended periods . the edta salts suitable for use in the subject invention include the common alkali metal and ammonium salts of edta . the sodium salts are preferred , for example the disodium and tetrasodium salts . the tetrasodium salt is preferred . a soluble nitrate salt , preferably an ammonium or alkali metal salt is used to supply nitrate to the composition . sodium nitrate is preferred , however other equivalent methods of supplying nitrate ions may also be used . for example , the ph of the total composition may be adjusted by addition of nitric acid which also has the advantage of supplying nitrate ions . the reaction of nitric acid and basic salts contained in the composition will result in liberation of free carboxylic acid and formation of nitrate salts . preferred cleaning solutions within the scope of the subject invention also include a corrosion inhibitor , particularly an inhibitor which prevents corrosion of aluminum . such corrosion inhibitors are well known to those skilled in the art , for example alkali metal silicates , siliconates , and silicone - silicate mixtures are useful corrosion inhibitors for aluminum . especially preferred is a stabilized silicate / silicone of the type disclosed by u . s . pat . nos . 4 , 370 , 255 , 4 , 362 , 644 , and 4 , 354 , 002 which are herein incorporated by reference . for corrosion protection on copper and brass , numerous derivatives are known commonly to those skilled in the art . preferred are benzotriazole and tolyltriazole . most preferred is tolytriazole as the sodium salt . also useful in the compositions of the subject invention is a mineral acid . the mineral acid may be used to obtain a favorable ph range , preferably from 7 to 14 , more preferably from 9 to 11 , or most preferably about 10 . 3 . the mineral acid may be useful in supplying nitrate to the composition when the mineral acid is nitric acid , but primarily is useful in preventing blackening and dissolution of aluminum through ph adjustment , for which the ph 9 - 11 range is preferred . the cleaning solution concentrates of the subject invention preferably contain , based on the weight of the concentrate , from 1 . 0 to about 30 . 0 percent , preferably from -. 0 to about 10 . 0 percent , and most preferably about 5 . 0 percent edta salt calculated on the basis of the tetrasodium salt ; from 1 . 0 to about 50 percent , preferably from 1 . 5 to about 30 percent , and most preferably about 20 percent sorbitol ; from 0 . 5 to about 8 . 0 percent , preferably from 1 . 0 to about 5 . 0 percent , and most preferably about 3 . 0 percent soluble nitrate salt calculated on the basis of sodium nitrate ; from 1 to about 15 , preferably from about 5 to 12 , and most preferably about 10 percent of a silicon containing corrosion inhibitor , preferably a stabilized silicone / silicate inhibitor ; and from 10 to about 50 percent , preferably from 20 to about 40 percent , and most preferably about 32 percent of a glycol , for example ethylene glycol , propylene glycol , diethylene glycol , or dipropylene glycol , and mixtures thereof . the balance of the composition is water , optionally containing low molecular weight alcohols such as methanol , ethanol , isopropanol , and the like . in the remainder of the specification and in the claims , this balance of the composition will be termed the &# 34 ; water miscible diluent .&# 34 ; preferably , the water miscible diluent is water or mixtures of water and lower alkanols . when the composition contains a mineral acid , the acid is preferably present in an amount , based again on the total solution , of from 0 . 5 to about 8 . 0 weight percent calculated on the basis of 35 weight percent nitric acid . preferably , the composition contains about 4 . 0 weight percent of 35 weight percent nitric acid . the composition may optionally contain other additional corrosion inhibitors , inert ingredients , surfactants of the nonfoaming type , polyoxyethylene glycols , biocides , fungicides , and so forth . also useful are dyes , particularly the fluorescent dyes such as the alizarine green and uranine yellow dyes . the cleaning solution of the subject invention has thus far been described in terms of a concentrate . the use of such concentrates allows for economical packaging and shipping , and generally are diluted with water or mixtures of water and commercial antifreeze or ethylene glycol for use . the ratio of dilution may vary , but is typically 1 : 20 . it is possible , of course , to prepare concentrates which are more dilute than the preferred concentrates of the subject invention . for example , a two - fold &# 34 ; diluted &# 34 ; concentrate would contain approximately half the weight percentage compositional ranges of the preferred concentrates , and correspondingly more water . if the concentrate is diluted enough , it may be possible to further reduce the glycol content from its proportional value . the term &# 34 ; storage stability &# 34 ; as used herein refers to the ability of the concentrate formulation to avoid precipitation and / or gelling at typical storage and shipment temperatures . storage stability is assessed visually by observing concentrates stored at various temperatures for varying lengths of time . it has been found , for example , that a glycol , preferably ethylene glycol must be present in the preferred concentrates , or gelation and / or precipitation may occur . if the concentrate is sold as a diluted concentrate , however , less ethylene glycol is expected to be necessary , and with certain formulations may be eliminated altogether . a cleaning concentrate was prepared at ph 10 . 3 from 5 . 0 parts tetrasodium edta , 20 . 0 parts sorbitol , 3 . 0 parts sodium nitrate , sufficient nitric acid to adjust the ph to 10 . 3 , 10 . 0 parts of stabilized silicone - silicate corrosion inhibitor , 32 . 0 parts ethylene glycol , and sufficient water to make 100 . 0 parts . it is possible to add water to obtain lower concentrations . the cleaning solution diluted approximately 1 : 19 with water , was circulated at 20 gallons / minute at 190 f and tested against new metal coupons of copper , solder , brass , mild steel , cast iron , and aluminum in a modified astm d2570 test , and on coupons having various types of scale , corrosion , and solder bloom . tests on the new metal coupons showed no significant metal loss . the solution also gave similar results in a more difficult modified astm d 1384 glassware corrosion test on new metal coupons . the solution was generally effective in removing corrosion and oxidation products on all oxidized and corroded coupons based on the modified astm d2570 test . the solution was particularly efficient in removing solder bloom . cast iron and steel coupons having moderate to heavy amounts of general and crevice corrosion and a moderate amount of rust , when treated , showed a small decrease in general . copper and brass coupons having moderate to heavy amounts of corrosion were treated and showed substantial decrease in corrosion . a portion of the copper coupon was even judged to be shiny following treatment . visual examination of all corroded metal coupon samples showed no detrimental effects , such as blackening or pitting , as a result of the simulated cleaning experiment .