Analysis of Heavy Metals in Cleaning Products

Final Report

for

The Soap and Detergent Association 475 Park Avenue South New York, NY 10016

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. Product Brands to be Collected and Composited 6 2. Sample Collection 7 3. Compositing Procedure 8 4. Instrument Parameters Atomic Absorption 9 5. Analytical Results 10 6. Method References 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, ~ew York

Instrumentation

• Spectrophotometer, Models 3300 and 5000, Perkin Elmer • Mercury/hydride system, Perkin Elmer Model MHS-20 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

~~ ~ QU..I.olOo-l . ~- Robert G. Allen Date Supervisor Inorganic Chemistry by and for Corning Hazleton 6

Table I

Product Brands To Be Collected and Composited4

Powder Laundry Detergents

Market Cumulative Density2 Weighting Brand Manufacturer Share! Share (gm/L) Factor3

Tide Procter & Gamble 23.8 23.8 560.5 29 Tide with bleach Procter & Gamble 10.6 34.4 607.0 14 Surf Lever Brothers 8.1 42.5 560.0 10 Cheer Procter & Gamble 7.9 50.4 560.0 10 Arm & Hammer Church & Dwight 6.6 57.0 640.0 9 Wisk Lever Brothers 6.2 63.2 560.0 8 Purex Dial 5.6 68.8 400.0 5 All Lever Brothers 5.2 74.0 600.0 7 Bold Procter & Gamble 2.4 76.4 557.8 3 Gain Procter & Gamble 2.3 78.7 560.5 3 Fab Colgate-Palmolive 1.8 80.5 550.0 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 City Sunnyvale Palo Alto San Jose

Tide 420z 420z 420z Tide with Bleach 470z 470z 470z Surf 420z 420z 420z Cheer 420z 420z 420z Arm & Hammer 4.51b 4.51b 4.51b Wisk 420z 420z 420z Purex 66 oz 66 oz 660z All 480z 480z 480z Bold 420z 420z 420z Gain 420z 420z 420z Fab 6 lb 2 oz 1 420z

1 This brand could not be located in Palo Alto. 8

Table 3

Compositing Procedure

Power Laundry Detergent Weight (grams)

Tide 174 Tide with Bleach 84 Surf 60 Cheer 60 Arm & Hammer 54 Wisk 48 Purex 30 All 42 Bold 18 Gain 18 Fab 12 9

Table 4

Instrument Parameters Atomic Ahsorption

Standard Analytical Solutions Wavelength Silt Range Element Techniaue Instrument ~nm) (nm) Gases !mmll

Arsenic Hydride PE 5000/MHS-20 193.7 0.7 Argon (carrier) 0.0 - 0.030 Cadmium Flame PE 3300 228.8 0.7 Air/acetylene 0.02 - 1.0 Chromium Flame PE 5000 357.9 0.7 N]O/acetylene 0.1 - 5.0 Copper flame PE 3300 324.7 0.7 Air/acetylene 0.02 - 1.0 Lead Flame PE 5000 283.3 0.7 Air/acetylene 0.0 - 3.0 Mercury Hydride PE 5000/MHS-20 253.7 0.7 Argon (carrier) 0.0 - 0.050 Nickel Flame PE 3300 232.0 0.2 Air/acetylene 0.1 - 5.0 Silver Flame PE 5000 328.1 0.7 Air/acetylene 0.05 - 1.0 Zinc Flame PE 3300 213.9 0.7 Air/acetylene 0.05 - 2.0

PE Perkin Elmer Corp., Norwalk, CT

MHS-20QP Perkin Elmer Mercury/Hydride System 10

Table 5

Analytical Results

Analyte Concentration (mg/Kg)

Powder Laundry Detergent As Cd Cr Cu Pb Hg Ni Ag Zn Assay I 0.295 <0.20 < 1.00 1.52 0.18 <0.025 < 1.00 1.01 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 Recovery (%) 105. 97.5 125. 117. 92.8 lOt. 80.5 103. 116. 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).