above processed material is cleaned with flow injection water until conductivity is detected as being lower than 1 5 um s preparation of phosphate buffer is achieved by dissolving 7 9 g nacl 0 2 g kcl 0 24 g kh 2 po 4 and 1 8 g k 2 hpo 4 into 800 ml distilled water adjusting the ph value by adding hcl solution to achieve a ph value of 7 4 then adding distilled water until the constant volume reaches 1 l the cleaning steps are conducted in the oscillation sink having ultrasonic cleaners with constant temperature first of all the materials are placed into the oscillation sink for cleaning and then sodium hydroxide solution is injected into the oscillation sink turning on the cleaners the cleaning time is 5 u02dc u02dc 30 min preferably for 20 min the sodium hydroxide solution concentration is 5 u02dc 100 mmol l preferably for 5 u02dc 20 mmol l further preferably for 10 mmol l then the cleaners are turned off and sodium hydroxide solution is poured out phosphate buffer solution is injected into the cleaner and turning on the cleaner the cleaning time is 5 u02dc 20 minutes preferably for 15 min repeating the phosphate buffer cleaning process for about 2 u02dc 5 times detecting the ph value of the phosphate buffer solution after cleaning when the ph value of the detected phosphate buffer solution is in the range from 6 5 to 7 5 the processed material by is cleaned by the flowing water for injection the flowing water cleaning process is terminated when a conductivity lower than 1 5 um s is detected the oscillation frequency of the cleaning step ranges from 100 to 300 rpm preferably for 200 rpm ultrasonic frequency ranges from 20 to.