On the ammonia process of water analysis

June, I89I.]

C/zemical Section.

46r

PROCEEDINGS OF

THE

@HEMICAL SECTION OF THE

FRANKLIN

INSTITUTE.

[Z*oceedz'Te~s of the staled meefinK, held Tuesday, May zg, x89L] H A L L OF THE FRANKLIN INSTITUTE, PHILADELPHIA, M a y I% 1891. Dr. WM. H. GREENE, Vice-President, in the chair. Sixteen m e m b e r s a n d seven visitors were present. Dr. W. P. Mason, of the Rensselaer Polytechnic Institute. of Troy, N. Y., read a p a p e r on, " D r i n k i n g W a t e r a n d Disease." It was referred for publication. A discussion of the paper, which was.of m u c h interest, followed, and was c o n d u c t e d b y the author and Messrs. P e m b e r t o n , Jayne a n d Haines. Mr. P e m b e r t o n called attention to the conditions of the water supply of Chester a n d discussed the effect of Philadelphia sewage upon it. Dr. Bruno T e r n e presented a paper on " M e a t Preservatives," giving a discussion of the ingredients a n d their effects upon the h u m a n system w h e n present in m e a t used as food. T h e paper was discussed b y the author a n d Mr. Haines. Adjourned. WM. C. DAY, Secretary.

ON THE A M M O N I A P R O C E S S OF W A T E R A N A L Y S I S . B Y REUBEN HAINES.

[ R e a d a l g/te staled meetinK, keld Aflril 2I, I39L ]

Two forms of this process are in use, 6ne dealing w i t h a half litre or a full litre of t h e water: the other r e q u i r i n g only ioo cc. for the distillation. T h e w r i t e r prefers t h e former, a l t h o u g h some c h e m i s t s find the l a t t e r fully as accurate a n d m o r e convenient. T h e following notes i n d i c a t e the practice of t h e w r i t e r for a n u m b e r of years, in addition to the i n s t r u c t i o n s g i v e n by W a n k l y n . T h e a m o u n t of sample u s e d is one-half litre, or, in some very i m p u r e waters, a less q u a n t i t y of the sample diluted to h a l f a litre with p u r e distilled water.

462

C-/ze~Jzic<~l, &'c~zoJz.

[ J. F. I.,

T h e retort is of large size, h a v i n g a capacity of from one-third to one-half gallon w h e n c o m p l e t e l y filled, a n d is s u p p o r t e d at t h e neck b y a large retort-clamp upon a h e a v y iron stand. It should not b e s u p p o r t e d oi1 a ring, u n l e s s wire gauze be interposed, as o t h e r w i s e there is g r e a t danger of fracture of t h e retort. If a Bunsen b u r n e r w i t h wire gauze is used close up b e n e a t h the retort with such a b o d y of liquid there is still d a n g e r of fracture. The neck of the r e t o r t is inclined ztpw(~rd at an angle of a b o u t 25 ° and a t t a c h e d to a L i e b i g c o n d e n s e r h a v i n g an inner t u b e of one inch diameter, b y a s h o r t piece of wide r u b b e r - t u b i n g in such m a n n e r t h a t the ends of the r e t o r t and condenser are in close c o n t a c t and t h a t as little r u b b e r as possible is e x p o s e d to t h e action of the hot vapor. In lieu of this a r r a n g e m e n t a few inches of the end of t h e retort-neck m a y be b e n t d o w n w a r d parallel w i t h the condenser, and be m a d e to enter loosely within the glass condenser tube; a short piece of r u b b e r - t u b i n g o v e r l a p p i n g t h e connection. In either ease, the r u b b e r should b e tied d o w n to p r e v e n t leakage, b u t in such m a n n e r t h a t t h e r e t o r t m a y readily b e disconnected at the conclusion of t h e analysis. T h e r u b b e r will h a v e to b e r e n e w e d after a time. The m o d e of connection r e c o m m e n d e d b y ~Vanklyn has b e e n s h o w n b y Dr. Smart, Mallet and others, to p e r m i t loss of a m m o n i a b y leakage. A rather rapid c u r r e n t of w a t e r should be m a i n t a i n e d in t h e Liebig condenser. If this c o n d e n s e r alone is used, t h e current should be so rapid t h a t t h e t e m p e r a t u r e of t h e w a t e r at t h e e x i t is not m a t e r i a l l y raised b y the operation if t h e w a t e r u s e d h a s an original t e m p e r a t u r e of from 5o ° to 6o ° P. If the w a t e r is of h i g h e r t e m p e r a t u r e t h a n this ice should b e u s e d for cooling it. A b e t t e r p l a n is that a d o p t e d by t h e writer, w h i c h consists in a t t a c h i n g t h e lower end of the L i e b i g c o n d e n s e r as closely as possible to a glass vertical coil c o n d e n s e r of the M o h r pattern, of w h i c h the o u t e r vessel is an i n v e r t e d jar r e c e i v e r (a large i n v e r t e d b o t t l e w i t h t h e b o t t o m c u t off will do v e r y well), into w h i c h b r o k e n ice m a y b e placed, espeeialiy irt hot weather. T h e glass t u b e f o r m i n g t h e coil h a s an inside

June, ,89r. ]

C/zcmical Section.

46~

diameter of a b o u t half an inch. Beneath this second condenser a s h o r t nearly horizontal tube, c o n d u c t s the distillate to the Nessler glass o u t of reach of c o n t a m i n a t i n g dust, etc., that m i g h t chance to fat1 from t h e vertical condenser. By h a v i n g the retort sufficiently large, and b y inclining its neck u p w a r d all danger of the p e r m a n g a n a t e b e i n g thrown over into the c o n d e n s e r is avoided. R i s k of fracture is greatly l e s s e n e d by the use of the retort d a m p , a n d b y the rod of the s t a n d acting as a sort of spring to m o d e r a t e the shock of b u m p i n g , and the retort m a y thus last in f r e q u e n t use for a v e r y long time. One of m i n e lasted several years, but it b e c a m e u n a v o i d a b l y w e a k e n e d in t i m e b y the corrosive action of t h e boiling alkaline liquid. By t h e abovedescribed a r r a n g e m e n t of t h e c o n d e n s i n g apparatus, the distillate m a y b e o b t a i n e d a t a given uniform t e m p e r a t u r e in all analyses in order to g e t u n i f o r m d e p t h s of color in the N e s s l e r testing, a p r e c a u t i o n to w h i c h some one h a s called attention. T h e risk of loss b y i m p e r f e c t condensation of a m m o n i a d u r i n g r e g u l a r distillation, or t h r o u g h t h e ontrush of g u s t s of v a p o r p r o d u c e d by t u r b u l e n t boiling is also avoided. T h e c o n d e n s i n g t u b e should, on a c c o u n t of this l a t t e r circumstance, be of c o m p a r a t i v e l y l a r g e diameter t h r o u g h o u t its w h o l e length. W i t h the above a r r a n g e m e n t I h a v e n o t found a n y loss b y imperfect condensation, if t h e t e m p e r a t u r e of the distillates did n o t exceed 6o ° P. If a lower t e m p e r a t u r e than this is adopted, the distillates should be allowed to s t a n d unti~ t h e y a c q u i r e a uniform t e m p e r a t u r e before a p p l y i n g the Nessler test. T h e a r r a n g e m e n t I have adopted w a s s u g g e s t e d b y reading tlle ]e~ort otz Water A1zalysis, b y Prof. Mallet, to the N a t i o n a l B o a r d of H e a l t h , I88z, in w h i c h this loss of ammonia o c c u r r i n g w h e n W a n k l y n ' s instructions are followed is referred to, and a s o m e w h a t different a r r a n g e m e n t suggested for a v o i d i n g it. In e x p e r i m e n t s with a known solution of a m m o n i u m chloride this loss w a s f o u n d by Dr. Smart to a m o u n t to an a v e r a g e of a b o u t seven per cent. of the whole a m o u n t t h a t should h a v e b e e n obtained. It should, however, b e n o t e d t h a t Mallet states that " t h e temperature of the c o n d e n s i n g w a t e r varied from 25 ° to 25°'5 C.!'

464

C/eem£a/

~S'eclioTz.

[ J. F. I.,

w h i c h is a r a t h e r h i g h t e m p e r a t u r e . In these e x p e r i m e n t s t h e current of w a t e r in the c o n d e n s e r was so rapid t h a t its t e m p e r a t u r e was not sensibly raised by the process, even when fifty ce. of distillate were o b t a i n e d in e i g h t m i n u t e s . T h e distillates of fifty ec. each are received d i r e c t l y into tile Nessler tubes m a r k e d at fifty ec., and tile earlier portions m a y be Nesslerized while the distillation is progressing. W a n k l y n advises to Nesslerize only the first distillate of fifty co. free N I t a and add to this one-third. In waters c o n t a i n i n g e n o r m o u s a m o u n t s of free a m m o n i a , however, it is b e t t e r either to distil the whole of t h e free a m m o n i a into a flask in one portion, dilute, and take an aliquot p a r t for t h e Nessler test, or to follow Dr. S m a r t ' s plan of N e s s l e r i z i n g each successive distillate of fifty" cc., previously d i l u t i n g if necessary. Dr. S m a r t t)elieves t h a t the presence of u]:ea in t h e water m a y be d e t e c t e d by peculiarities ill the m a n n e r in which the free a m m o n i a distils over in the successive portions. I h a v e f o u n d t h a t polluted w a t e r s c o n t a i n i n g e n o r m o u s a m o u n t s of free a m m o n i a such as to give a v e r y deep color or a precipitate by the Nessler test in fifty" ec. of the original sample appear to yield four-fifths or fivesixths of the whole a m o u n t in the first portion of rift)" co. instead of three-fourths, as s t a t e d by \ V a n k l y n . It is not advisable to p u t a n y t h i n g w h a t e v e r , such as pieces of i g n i t e d pumice, tobacco pipe, etc., inside the r e t o r t to m o d e r a t e t h e b u m p i n g , as s u g g e s t e d by some, t h e r e b e i n g too m u c h d a n g e r of i n t r o d u c i n g t h e r e b y organic or a m m o n i a c a l i m p u r i t y . T h e b u m p i n g can be controlled if necessary by l o w e r i n g the flame a n d by t a p p i n g g e n t l y on t h e retort so as to produce a concentric w a v y m o t i o n on t h e surface of the liquid, which will cause the s t e a m to rise m o r e regularly and in smaller bubbles. A Bunsen burner, g i v i n g a large flame, should be used. I prefer one h a v i n g several jets, or a rose-burner, and place it quite close to the retort, w i t h o u t a n y i n t e r v e n i n g wire gauze. All t h e a p p a r a t u s used for w a t e r analysis should be set aside exclusively for this purpose. T h o r o u g h w a s h i n g of each article i m m e d i a t e l y before use is v e r y essential. T o be t h o u g h t " d e a n e n o u g h " is by no m e a n s sufficient. T h e

June, I891.]

Chemical Section.

465

whole c o n d e n s i n g a p p a r a t u s set up r e a d y for use, b u t dis~ connected from t h e retort, can be satisfactorily w a s h e d b y flushing it t h o r o u g h l y t w o or three t i m e s w i t h clean h y d r a n t water, closing t h e outlet b y t h e finger or a d e a n cork until the c o n d e n s e r t u b e is full and then allowing the water to run out. T h i s m e t h o d of w a s h i n g is m u c h b e t t e r t h a n distilling s o m e clean w a t e r t h r o u g h it as a d v i s e d b y some. The retort s h o u l d be rinsed with a little concentrated sulphurie acid and w a s h e d t h o r o u g h l y w i t h d e a n tap water, and then i m m e d i a t e l y c o n n e c t e d w i t h the condenser. T h e a b o v e form of a p p a r a t u s m a y be considered b y s o m e to be c u m b r o u s and to o c c u p y too m u c h space, y e t I think it possesses certain real a d v a n t a g e s w h i e h offset these objections. T h e atkaline p e r m a n g a n a t e solution can readily be prepared so p u r e t h a t one litre of it u n d i l u t e d yields bydistillation not m o r e than o"oo5 m i l l i g r a m m e s NHa and t h a t no m o r e ammonia d e v e l o p s in it a f t e r w a r d if properly protected. I have been u s i n g for m o r e than ten y e a r s solutions prepared to this d e g r e e of purity, m a d e up in q u a n t i t i e s of one litre, which have kept welt. T h e p r e p a r a t i o n is accomplished b y using only v e r y good distilled w a t e r f o r m a k i n g up the solution, and b y n o t p e r m i t t i n g the sticks of caustic p o t a s h (ordinary w h i t e sticks) to come in c o n t a c t w i t h a n y kind of organic s u b s t a n c e in h a n d l i n g and w e i g h i n g it out. T h e mixed solution is diluted to one and one-half litres and distilled in a large retort, slowly, until a b o u t 900 ee. remain, and then 50 co. are t e s t e d w i t h N e s s l e r solution. If pure, the solution is t r a n s f e r r e d w h e n cold to a litre flask and made up to the m a r k with p e r f e c t l y pure distilled water, made free from a m m o n i a and organic m a t t e r by distillation with some solution of alkaline p e r m a n g a n a t e of potash. I found that if r i v e r w a t e r from a h y d r a n t was used in making t h e s o l u t i o n it w a s v e r y difficult to obtain a solution perfectly free f r o m a m m o n i a , even after W r y p r o t r a c t e d slow boiling. If an i m p u r e solution is used, and a correction applied for the i m p u r i t y it contains, it will be found that the results of analysis are t h e r e b y s u b j e c t e d to error. I strongly s u s p e c t that errors from t h a t c a u s e did occur in

466

C/zenzical 5Yclion.

[J. F. I.,

some of m y earliest analyses m a n y years ago. L i a b i l i t y to error from this cause has been noticed also b y others. W a n k l y n , I think, never applied a correction for impurity, b u t always prepared the solution free from NHa, if I understand rightly a certain discussion w h i c h took place in t h e early history of the process. Yet Dr. Tidy, in I879, dectared the preparation of a solution of alkaline p e r m a n g a n a t e , free from ammonia, to be impossible, and said that he a l w a y s had to make a correction for the a m m o n i a ke found it to contain. This w a s one of the several o b j e c t i o n s that w e r e strongly u r g e d a g a i n s t the a m m o n i a process of analysis. On the other hand, Prof. Mallet states, in his R e p o r t to t h e National Board of Health, i882, that Dr. S m a r t in t h e investigations for that report m a d e up his s o l u t i o n w i t h good distilled water, and after t h e requisite boiling " i t g a v e no coloration w i t h Nessler r e a g e n t in fifty cc. distilled off from one-half litre." Care should always be t a k e n to rinse off the s t o p p e r e d m o n t h of the b o t t l e c o n t a i n i n g t h e p e r m a n g a n a t e solution b o t h i m m e d i a t e l y before and after use, n o t w i t h s t a n d i n g it m a y have been carefully p r o t e c t e d from l a b o r a t o r y vapors,etc. T h e rate at which both the free and a l b u m i n o i d a m m o nia is evolved often affords v a l u a b l e i n f o r m a t i o n as to t h e character of the organic m a t t e r c o n t a i n e d in t h e water, a n d therefore the details of the s e p a r a t e N e s s l e r testings s h o u l d be preserved for reference. If, as s o m e t i m e s happens, a peculiar odor is'noticeable in the free a m m o n i a distillate it m a y be p r e s u m e d to be due to t h e volatile organic m a t t e r w h i c h has passed over with the free ammonia, b u t w h i c h will p r o b a b l y n o t produce a reaction with the Nessler t e s t solution and be lost to the analysis. In this case a s e c o n d distillation with alkaline perman.ganate a d d e d at first s h o u l d be made with a fresh portion of t h e sample, t h u s o b t a i n i n g t h e total ammonia, the free and a l b n m i n o i d coming over together. If the a m o u n t of total a m m o n i a is sensibly larger than the s u m of the free a n d a l b u m i n o i d o b t a i n e d in the first distillation, the difference m a y be a s s u m e d to be a m m o n i a from volatile organic m a t t e r . F r o m m y own experience d u r i n g a b o u t e i g h t years, in

June, 189I.]

Chemical Section.

467

whidh I h a v e v e r y frequently r e p e a t e d the distillaton in t h e above manner, I am led to believe t h a t the occurrence of a voIatile organic s u b s t a n c e in well w a t e r s is at least a c o m p a r a t i v e l y rare circumstance. T h e t e s t is, however, a useful check u p o n the accuracy of the analysis. T h e s a m e proportions s h o u l d be a d h e r e d to in the second as in the first distillation as r e g a r d s the alkaline p e r m a n g a n a t e and the q u a n t i t y of w a t e r o p e r a t e d upon. Prof. R e m s e n found, however, in 1881 a striking instance of the presence of volatile organic matter, which failed to be e s t i m a t e d b y the ordinary m e t h o d of p r o c e d u r e in his investigations into the W'ater S u p p l y of Baltimore. Soon afterwards, Mr. Chas. ~\r. Marsh, then at Princeton, p u b l i s h e d a paper, in the zTmer. Clzem. Jo~trnal, giving a n u m b e r of instances of similar n a t u r e in well and cistern waters which he had examined. T h e possibility of this occurrence should therefore b e recognized and provision m a d e for the estimation of t h e volatile organic substance. ANALYSIS

ov AN A R T E S I A N

WELL

WATER.

]~Xr R E U B E N H A I N E S .

[Read at the staled meeting, keld M~ril 2z, I89 L]

T h e well from which the w a t e r is derived, of which an analysis is here given, is s i t u a t e d in a closely built-up portion of G e r m a n t o w n . It was sunk in I875 to the depth of 312 feet, m o s t l y t h r o u g h soft rock which w a s p r o b a b l y a micaceous schist. I w a s i n f o r m e d that about half-way down a s t r a t u m was entered w h i c h carried large q u a n t i t i e s of iron garnets, similar to those found in t h e surface rock and w a s h i n g s at -Wayne Junction. A t the b o t t o m a cavity in the rock was a p p a r e n t l y entered, for a portion of the drilling a p p a r a t u s s u d d e n l y dropped, and, failing to one side, was lost a n d n e v e r recovered. T h e rock was first s t r u c k at a b o u t e i g h t feet from the surface of t h e ground. T h e w a t e r rose to a level of a b o d t thirteen feet b e l o w t h e surface, and the a v e r a g e flow by pumping has since b e e n forty gallons per minute, w i t h o u t