Table la: ConLaini iiat 1 on ConLrol Procedures: ScawaLer 



ITEM 



PROCEDURE 



Sampling 



Performed outside of zone of influence of 

 vessel; sub-surface sample taken to avoid 

 highly fractionated surface film; workers 

 wear plastic gloves. 



Sampling Apparatus: CPE collec- 

 tion bottles, Millipore filtering 

 apparatus, O.AlJ Nucleopore mem- 

 branes, polyethylene forceps. 



Three stage acid leaching (Cone, reagent 

 grade HNO , three days exposure at 60 C; 

 2N HNO , three days exposure at 60°C; 0.2N 



ultrapure HNO , three days exposure at 60 C; 

 intermediate rinses with distilled deionized 

 water (DDIW) , final rinse with sub-boiling 

 quartz-distilled water (Q-DDIW) ; air drying 

 under particle free ultra-clean hood in Class 

 100-A Clean Laboratory. 



Storage bottles (CPE), membrane 

 storage vials (CPE) . 



Three-stage acid-leaching; bottles taken to 

 field in double plastic bags, filled in bags, 

 returned to clean lab in bags. 



Acids for sample preservation (HCl) , 

 for third stage cleaning (HNO ) , 

 for chelation-extraction precon- 

 centration (HNO ) . 



Extraction Materials: (i) handling: 

 Teflon beakers, separatory funnels, 

 CPE micro-pipette tips, polyvials 

 for AAS, (ii) reagents: 



APDC-DDDC 



acids 



Freon 



NH , OH 

 4 



Purification of Baker Analysed Reagent Grade 

 acids by two sub-boiling distillations in 

 Teflon apparatus. 



Three-stage acid leaching. 



Triple freon extraction. 



As described earlier 



No purification required; frequent reagent 



blank analyses performed 



Q-DDIW equilibrated with cone. NH OH in 



dessicator jar 



Extractions, acid-cleaning, reagent 

 purification 



Carried out in Class 100-A ultra-clean lab- 

 oratory; workers wear plastic gloves, changed 

 frequently to avoid cross-contamination. 



