t e r 3800 East Colfax Avenue Denver, CO 80206
Reynolds' (1963) lead c i t r a t e has been in use in E M laboratories for t w e n t y years, y e t t h e prablern of lead c a r b o n a t e precipitation remains. T h e following is a description of lead c i t r a t e preparation and usage; if t h e s e instructions a r e followed accurately, very clea;i sections will result reliably.
General Directions All activities must b e c a r r i e d out meticulously. All errors should b e c o r r e c t e d by repeating t h e procedure. All c o n t a c t s between a i r and lead solution should be minimized. R e a g e n t s Old lead salts do not stain well (Reynolds,l963), sodium c i t r a t e gradually will lose i t s water c o n t e n t , 1 N NaOH will absorb C 0 2 froin t h e atmosphere; therefore, quality reagents must b e bought every 6 -9 months. (Sodium c i t r a t e -Baker "Analyzed" Reagent, Lead V i t r a t e -Baker "Analyzed" Reagent, I N NaOH in Carbonate F r e e H 2 0 -VUR).
Preparation of L e a d C i t r a t e
Acid wash all glassware and then rinse t e n t i m e s with double distilled water. Dry. Boil rapidly for ten minutes approximately 125 mi double distilled HZO. , Cool to room temperature. V e a s u r e 60rnl of this i n t o a g r a d u a t e and set 3sidn. K e i g i i n s e p a r a t e disposable weigh boats: 2.66 gm lead n i t r a t e , P b (N03)2, and 3.52 gin sodiwn c i t r a t e , %a3 (C6Hj07). 2H20.