Final Report
Analysis of Heavy Metals in Cleaning Products
for
The Soap and Detergent Association
475 Park Avenue South
New York, NY 10016
by
Corning Hazleton
3301 Kinsman Boulevard
Madison. WI 53704
Author
Robert G. Allen
June 8, 1995
2
CONTENTS
Page
INTRODUCTION
3
SAMPLE COLLECTION
3
COMPOSITING PROCEDURE
3
MATERIALS
3
SAMPLE ANALYSIS
4
SIGNATURE
5
TABLES
1.
2.
3.
4.
5.
6.
Product Brands to be Collected and Composited
Sample Collection
Compositing Procedure
Instrument Parameters Atomic Absorption
Analytical Results
Method References
6
7
8
9
10
11
3
INTRODUCTION
Composite samples of powder laundry detergent were analyzed for arsenic, cadmium, chromium,
copper, lead, mercury, nickel, silver, and zinc to develop background information on the potential
contribution of these products to the heavy metal contamination of municipal sewage. The Soap and
Detergent Association (SDA) previously sponsored a study in which the concentrations of these same
heavy metals were measured in composite samples of seven categories of cleaning products which are
known to be disposed into sewage. Since the completion of this study, powder laundry detergents
have undergone widespread reformulation. This matrix was reexamined to determine if the heavy
metal content was altered.
SAMPLE COLLECTION
Eleven different brands of powder laundry detergent were collected from stores in three California
cities: Sunnyvale, Palo Alto, and San Jose. A 35 - 45 ounce container was to be purchased in each
municipality. Table I was reprinted from The Soap and Detergent Association scope of work and
lists the product brands to be collected and composited. Table 2 lists the container size collected in
each area.
COMPOSITING PROCEDURE
Eleven within-brand composites were prepared by combining each of the single containers from each
of the three cities. From these composites, a subsample was removed based on the market share to
prepare the between-brand composite (Table 3). A total of 600 grams was prepared and subdivided
into three acid-washed polyethylene bottles (amber, wide-mouthed, 250 mL size). Two of these
samples were used for analysis and the third was kept as a reserve sample.
MATERIALS
Reagents
•
•
•
•
•
Water, double-deionized, in-house
Nitric acid, Mallinckrodt Chemical, Inc., Paris, Kentucky
Sulfuric acid, Fisher Scientific, Pittsburgh, Pennsylvania
Sodium borohydride, Aldrich Chemical Company, Milwaukee, Wisconsin
Stock standard solutions, Fisher Scientific, Pittsburgh, Pennsylvania
Equipment
•
General laboratory glassware, Coring Glassworks, Corning,
Instrumentation
•
•
Spectrophotometer, Models 3300 and 5000, Perkin Elmer
Mercury/hydride system, Perkin Elmer Model MHS-20
~ew
York
4
SAMPLE ANALYSIS
Cadmium. Chromium. Copper. Lead. Nickel. Silver. and Zinc
The samples were digested with nitric acid in glass beakers on a hot plate, transferred to 50 mL
volumetric flasks, filtered, and analyzed by atomic absorption spectroscopy.
Arsenic
The samples were digested with a mixture of sulfuric and nitric acids, transferred to 25 mL
volumetric flasks, and analyzed by hydride generation.
Mercury
The samples were digested with a mixture of sulfuric and nitric acids, transferred to 100 mL
volumetric flasks, and analyzed by cold vapor atomic absorption spectroscopy.
All of the analyses were performed using atomic absorption spectroscopy. The instrument operating
parameters are included in Table 4. Analytical results are listed in Table 5.
Spikes were prepared to test for matrix effects. The amount of each analyte added and the respective
percent recovery are listed in Table 5. Recoveries ranged from 80.5 - 125 %.
5
SIGNATURE
~~ ~
l .
QU..I.olOo~-
Robert G. Allen
Supervisor
Inorganic Chemistry
by and for Corning Hazleton
Date
6
Table I
Product Brands To Be Collected and Composited4
Powder Laundry Detergents
Brand
Manufacturer
Tide
Tide with bleach
Surf
Cheer
Arm & Hammer
Wisk
Purex
All
Bold
Gain
Fab
Procter & Gamble
Procter & Gamble
Lever Brothers
Procter & Gamble
Church & Dwight
Lever Brothers
Dial
Lever Brothers
Procter & Gamble
Procter & Gamble
Colgate-Palmolive
Market
Share!
Cumulative
Share
Densi ty2
(gm/L)
23.8
10.6
8.1
7.9
6.6
6.2
5.6
5.2
2.4
2.3
1.8
23.8
34.4
42.5
50.4
57.0
63.2
68.8
74.0
76.4
78.7
80.5
560.5
607.0
560.0
560.0
640.0
560.0
400.0
600.0
557.8
560.5
550.0
Weighting
Factor3
29
14
10
10
9
8
5
7
3
3
2
!Information Resources, Inc., personal communication, 1994.
2Personal communications with manufacturers.
3Weighting factor = [Powder detergent market share x Density] / E[Powder detergent market share x
Density] x 100
4Reprinted from The Soap and Detergent Association scope of work.
7
Table 2
Sample Collection
Brand
Tide
Tide with Bleach
Surf
Cheer
Arm & Hammer
Wisk
Purex
All
Bold
Gain
Fab
Sunnyvale
City
Palo Alto
San Jose
420z
470z
420z
420z
4.51b
420z
66 oz
480z
420z
420z
6 lb 2 oz
420z
470z
420z
420z
4.51b
420z
66 oz
480z
420z
420z
1
420z
470z
420z
420z
4.51b
420z
660z
480z
420z
420z
420z
1 This brand could not be located in Palo Alto.
8
Table 3
Compositing Procedure
Power Laundry Detergent
Tide
Tide with Bleach
Surf
Cheer
Arm & Hammer
Wisk
Purex
All
Bold
Gain
Fab
Weight (grams)
174
84
60
60
54
48
30
42
18
18
12
9
Table 4
Instrument Parameters
Atomic Ahsorption
Analytical
Wavelength
Element
Techniaue
Instrument
Arsenic
Cadmium
Chromium
Copper
Lead
Mercury
Nickel
Silver
Zinc
Hydride
Flame
Flame
flame
Flame
Hydride
Flame
Flame
Flame
PE
PE
PE
PE
PE
PE
PE
PE
PE
PE
5000/MHS-20
3300
5000
3300
5000
5000/MHS-20
3300
5000
3300
Perkin Elmer Corp., Norwalk, CT
MHS-20 QP Perkin Elmer Mercury/Hydride System
~nm)
193.7
228.8
357.9
324.7
283.3
253.7
232.0
328.1
213.9
Standard
Solutions
Range
Silt
(nm)
Gases
0.7
0.7
0.7
0.7
0.7
0.7
0.2
0.7
0.7
Argon (carrier)
Air/acetylene
N]O/acetylene
Air/acetylene
Air/acetylene
Argon (carrier)
Air/acetylene
Air/acetylene
Air/acetylene
!mmll
0.0 - 0.030
0.02 - 1.0
0.1 - 5.0
0.02 - 1.0
0.0 - 3.0
0.0 - 0.050
0.1 - 5.0
0.05 - 1.0
0.05 - 2.0
10
Table 5
Analytical Results
Analyte Concentration (mg/Kg)
Powder Laundry Detergent
Assay I
As
0.295
Cd
<0.20
Cr
< 1.00
Cu
1.52
Pb
0.18
Hg
<0.025
Ni
< 1.00
Ag
1.01
Zn
4.02
Assay 2
0.308
<0.20
< 1.00
1.63
0.20
<0.025
< 1.00
1.08
4.11
Analyte Added (lLg)
1.00
4.0
20.0
8.0
4.0
0.20
10.0
10.0
20.0
105.
97.5
125.
117.
92.8
lOt.
80.5
103.
116.
Recovery (%)
11
Table 6
Method References
Arsenic by Hydride Generation
Digestion: Analytical Methods Committee, The Analyst, Volume 85, Pages 643-656 (1960)
(Modified).
Perkin Elmer, Analytical Methods Using the MHS Mercury/Hydride System, Norwalk, CT., January,
1981 (Modified).
Cadmium
Official Methods of Analysis of the Association of Official Analytical Chemists, 15th Edition, Method
974.27, Arlington, VA., (1990) (Modified).
Perkin Elmer, Analytical Methods for Atomic Absorption Spectrophotometry, Norwalk, Ct., January
1982 (Modified)
Methods for Chemical Analysis of Water and Wastes (1979), Metals 1-19 and Method 213.1, U.S.
EPA, Cincinnati, OH (Modified).
Chromium
Perkin Elmer, Analytical Methods for Atomic Absorption Spectrophotometry, Norwalk, CT, January
1982 (Modified).
Methods for Chemical Analysis of Water and Wastes (1979), Metals 1-19 and Method 218.1, U.S.
EPA, Cincinnati, OH (Modified).
Lead
Official Methods of Analysis of the AOAC, 15th Edition, Methods 972.23, 973.35 and 974.27,
AOAC, Arlington, VA. (1990) (Modified).
Friend, M.T., Smith, C. A., and Wishart, D., Atomic Absorption Newsletter, Volume 16, No.2,
Pages 46-49 (1979) (Modified)
Mercury
Digestion: Analyst, Volume 86, Page 608 (1961) (Modified).
Determination: Analytical Chemistry, Volume 40, Page 2085 (1968) (Modified).
Nickel
Perkin Elmer, Analytical Methods for Atomic Absorption Spectrophotometry, Norwalk, CT, January
1982 (Modified).
Methods for Chemical Analysis of Water and Wastes (1979), Metals 1-19 and Method 249.1, U.S.
EPA, Cincinnati, OH (Modified).
12
Table 6 (Continued)
Silver
Perkin Elmer, Analytical Methods for Atomic Absorption Spectrophotometry, Norwalk, CT, January
1982 (Modified).
Methods for Chemical Analysis of Water and Wastes (1979), Metals 1-19 and Method 272.1, U.S.
EPA, Cincinnati, OH (Modified).
Zinc
Official Methods of Analysis of the Association of Official Analytical Chemists, 15th Edition,
Methods 965.09, 968.08, 969.32 and 985.35, Arlington, Virginia (1990) (Modified).