ON THE OCCURRENCE OF TIN IN CANNED FOOD.
Reading edition
By H.A. WEBER, Ph.D.
The following investigation of the condition of foods packed in tin cans was prompted by an alleged case of poisoning, which occurred at Mansfield, Ohio, in April, 1890. A man and woman were reported to the writer as having been made sick by eating pumpkin pie made from canned pumpkin. The attending physician pronounced the case one of lead poisoning. The wholesale dealer from whose stock the canned pumpkin originally came, procured a portion of the same at the house where the poisoning occurred, and sent it to the writer for examination.
The results of the examination as reported in Serial No. 552, below, showed that the canned pumpkin contained an amount of stannous salts equivalent to 6.4 maximum doses and 51.4 minimum doses of stannous chloride per pound. On being notified of this fact, the dealer sent a can of the same brand of pumpkin from his stock. The inner coating of the can was found to be badly eroded, and upon examination, as reported in Serial No. 563, below, one pound of the pumpkin contained tin salts equivalent to 7 maximum and 56 minimum doses of stannous chloride.
The unexpected large amount of tin salts in such an insipid article as canned pumpkin, and the claimed ill effects of the consumption of the same, suggested the advisability of extending the investigation to other canned goods in common use. Accordingly a line of articles was purchased in open market as sold to consumers, no pains being taken to procure old samples. The collection embraced fruits, vegetables, fish and condensed milk. With the exception of the condensed milk, every article examined was contaminated with salts of tin. In most cases the amount of tin salts present was so large that there can be no doubt of danger to health from the consumption of the food, especially if several kinds are consumed at the same meal.
METHOD.
The method employed in the determination of the tin was simply as follows:
The contents of each can were emptied into a large porcelain dish, and the condition of the inner coating of the can noted. After thoroughly mixing the contents, fifty grammes were weighed off and incinerated in a porcelain dish of suitable size. The residue was treated with a large excess of concentrated hydrochloric acid, evaporated to dryness, moistened with hydrochloric acid, water was added, and the mass was filtered and washed, the insoluble matter being all washed upon the filter. After drying the filter with its contents, the whole was again incinerated in a porcelain dish and the residue treated as before. The solution thus obtained was properly diluted and saturated with hydrogen sulphide. After standing about twelve hours in a covered beaker the precipitate was filtered off and the tin weighed as stannic oxide.
RESULTS OF EXAMINATION.
Serial No. 552.—Sample of canned pumpkin, received of F.A. Derthick, April 22, 1890, sent by Albert F. Remy & Co., Mansfield, Ohio. Pie made from it supposed to have made a man and woman sick. The attending physician pronounced the case one of lead poisoning.
Per cent.
Tin dioxide with trace of lead0.0424
Grains per pound2.97
Equivalent to stannous chloride3.74
Minimum doses51.4
Maximum doses6.4
Serial No. 563.—Sample of canned pumpkin, received of Edward Bethel, June 27, 1890. Labeled: Choice Pie Pumpkin, packed at Salem, Columbiana County, Ohio, by G.B. McNabb, sent by A.F. Remy & Co., Mansfield, Ohio.
Per cent.
Tin dioxide0.0444
Grains per pound3.11
Equivalent to stannous chloride3.91
Minimum doses56
Maximum doses7
Can eroded.
Serial No. 565.—Sample of canned pumpkin, bought of T.B. Vaure, July 11, 1890. Labeled: Belpre Pumpkin, Golden. George Dana & Sons, Belpre, Ohio.
Per cent.
Tin dioxide0.0054
Grains per pound0.38
Equivalent to stannous chloride0.48
Minimum doses7.7
Maximum doses1.0
Can eroded.
Serial No. 566.—Sample of canned Hubbard Squash, bought of T.B. Vaure, July 11, 1890. Labeled: Ladd Brand, L. Ladd, Adrian, Michigan.
Per cent.
Tin dioxide0.026
Grains per pound1.85
Equivalent to stannous chloride2.33
Minimum doses37.00
Maximum doses4.7
Can badly eroded.
Serial No. 567.—Sample of canned tomatoes, bought of T.B. Vaure, July 11, 1890. Labeled: Extra Fine Tomatoes. Blue Label. Curtice Bros. Co., Rochester, N.Y.
Per cent.
Tin dioxide0.012
Grains per pound0.84
Equivalent to stannous chloride1.06
Minimum doses16.00
Maximum doses2.00
Inner coating eroded.
Serial No. 568.—Sample of canned tomatoes, bought of T.B. Vaure, July 11, 1890. Labeled: Fresh Tomatoes, Curtice Bros. Co., Rochester, N.Y.
Per cent.
Tin dioxide0.014
Grains per pound0.98
Equivalent to stannous chloride1.23
Minimum doses19.00
Maximum doses2.5
Can eroded.
Serial No. 569.—Sample of canned peas, bought of T.B. Vaure, July 11, 1890. Labeled: Petites Pois, P. Emillien, Bordeaux.
Per cent.
Copper oxide0.0294
Grains per pound2.06
Equivalent to copper sulphate3.95
Tin dioxide0.0068
Grains per pound0.48
Equivalent to stannous chloride0.6
Minimum doses9.6
Maximum doses1.2
No visible erosion.
Serial No. 570.—Sample of canned mushroom, bought of T.B. Vaure, July 11, 1890. Labeled Champignons de Choix. Boston fils. Paris.
Per cent.
Tin dioxide0.02
Grains per pound1.40
Equivalent to stannous chloride1.76
Minimum doses28.00
Maximum doses3.50
Inner coating highly discolored.
Serial No. 571.—Sample of canned blackberries, bought of T.B. Vaure, July 11, 1890. Labeled: Lawton Blackberries. Curtice Bros. Co., Rochester, N.Y.
Per cent.
Tin dioxide0.0114
Grains per pound0.80
Equivalent to stannous chloride1.01
Minimum doses16.00
Maximum doses2.00
Inner coating eroded.
Serial No. 572.—Sample of canned blueberries, bought of T.B. Vaure, July 11, 1890. Labeled: Blueberries. Eagle Brand, packed by A. & R. Loggie, Black Brook, N.B.
Per cent.
Tin dioxide0.03
Grains per pound2.10
Equivalent to stannous chloride2.64
Minimum doses42.00
Maximum doses5.30
Can badly eroded.
Serial No. 574.—Sample of canned salmon, bought of T.B. Vaure. July 11, 1890. Labeled: Best Fresh Columbia River Salmon, Eagle Canning Co., Astoria Clatsop Co., Oregon.
Per cent.
Tin dioxide0.0134
Grains per pound0.94
Equivalent to stannous chloride1.18
Minimum doses18.90
Maximum doses2.30
Inner coating eroded.
Serial No. 578.—Sample of canned pears, received of Mr. Edward Bethel, July 29, 1890. Labeled: Bartlett Pears. Solan's Brand, packed in Solano Co., California.
Juice. Per Ct.Fruit. Per Ct.
Tin dioxide0.00740.0074
Grains per pound0.51800.5180
Equivalent to stannous chloride0.650.65
Minimum doses10.4010.40
Maximum doses1.301.30
Can eroded.
Serial No. 579.—Sample of canned peaches, received of Edward Bethel, July 29. 1890. Labeled: Peaches, Wm. Maxwell, Baltimore, U.S.A.
Juice. Per Ct.Fruit. Per Ct.
Tin dioxide0.03240.0414
Grains per pound2.26802.8980
Equivalent to stannous chloride2.853.65
Minimum doses45.6058.40
Maximum doses5.707.30
Can badly eroded.
Serial No. 580.—Sample of canned blackberries, received of Edward Bethel, July 29, 1890. Labeled: Blackberries, Clipper Brand, Wm. Munson & Sons, Baltimore, Md.
Per cent.
Tin dioxide0.06
Grains per pound4.20
Equivalent to stannous chloride5.28
Minimum doses84.00
Maximum doses10.60
Can badly eroded.
Serial No. 581.—Sample of canned cherries, received of Edward Bethel, July 29, 1890. Labeled: Red Cherries, Cloverdale Brand, G.C. Mournaw & Co., Cloverdale, Va.
Per cent.
Tin dioxide0.0414
Grains per pound2.8980
Equivalent to stannous chloride3.65
Minimum doses58.40
Maximum doses7.30
Can badly eroded.
Serial No. 582.—Sample of canned pumpkin, received of Edward Bethel, July 29, 1890. Labeled: Royal Pumpkin, Urbana Canning Co., Urbana, O.
Per cent.
Tin dioxide0.0184
Grains per pound1.2990
Equivalent to stannous chloride1.62
Minimum doses25.90
Maximum doses.3.20
Can eroded.
Serial No. 583.—Sample of canned baked sweet potatoes, received of Edward Bethel, July 29, 1890. Labeled: Tennessee Baked Sweet Potatoes, Capital Canning Co., Nashville, Tenn.
Per cent.
Tin dioxide0.0132
Grains per pound0.92
Equivalent to stannous chloride1.16
Minimum doses18.50
Maximum doses2.30
Can eroded.
Serial No. 584.—Sample of canned peas, received of Edward Bethel, July 29, 1890. Labeled: Marrowfat Peas, Parson Bros., Aberdeen, Maryland.
Per cent.
Tin dioxide0.0044
Grains per pound0.30
Equivalent to stannous chloride0.38
Minimum doses6.20
Maximum doses0.80
Can slightly eroded.
Serial No. 585.—Sample of string beans, received of Edward Bethel, July 29, 1890. Labeled: String Beans. Packed by H.P. Hemingway & Co., Baltimore City, Md.
Per cent.
Tin dioxide0.0154
Grains per pound1.08
Equivalent to stannous chloride1.36
Minimum doses21.70
Maximum doses2.70
Can eroded.
Serial No. 586.—Sample of canned salmon, received of Edward Bethel, July 29, 1890. Labeled: Puget Sound Fresh Salmon, Puget Sound Salmon Co., W.T.
Per cent.
Tin dioxide0.0044
Grains per pound0.30
Equivalent to stannous chloride0.38
Minimum doses0.20
Maximum doses0.80
Can slightly eroded.
Serial No. 587.—Sample of condensed milk, received of Edward Bethel, July 29, 1890. Labeled: Borden's Condensed Milk. The Gail Borden Eagle Brand, New York Condensed Milk Co., 71 Hudson Street, New York.
Tin dioxide none.
No visible erosion.
Serial No. 592.—Sample of canned pineapples, bought of Mr. Brown, Fifth Avenue, August 4, 1890. Labeled: Pineapples, First Quality. Packed by Martin Wagner & Co., Baltimore, Md.
Per cent.
Tin dioxide0.0098
Grains per pound0.6860
Equivalent to stannous chloride0.8640
Minimum doses13.6
Maximum doses1.7
Can eroded
Serial No. 593.—Sample of canned pineapples, bought of Mr. Brown, Fifth Avenue, August 4, 1890. Labeled: Florida Pineapple, Oval Brand. Extra Quality. A Booth Packing Co., Baltimore, Md.
Per cent.
Tin dioxide0.0158
Grains per pound1.11
Equivalent to stannous chloride1.40
Minimum doses22.40
Maximum doses2.80
Can eroded.
—Jour. Amer. Chem. Soc.