J. Agric. Food Chem. 1983, 31 1244-1249
1244
Table VII. Comparison of Mean Cadmium and Lead Levelsa in Five Crops soybeans
reference
lettuce
potatoes
thisstudy FDA~ other studies
0.026 0.048 0.048c 0.0295c
Cadmium 0.031 0.059 0.037 0.092 0.O49gc 0.O44Eic
thisstudy FDA~ other studies
0.013 0.075 0.02gd 0.033, 0.62‘
sweet corn 0.0031 0.018 0.0065d
Lead 0.009 0.042 0.0033 0.038 0.095 0.018 0.0666 0.22d 0.O74gc
wheat 0.043 0.065 0.066e 0.096e 0.037 0.115
bg/g of wet weight. Compliance Program Evaluation (1977). Kaferstein (1980). Shacklette (1980). e Andersson and Pettersson (1981).
in the same soils and geographical area. Other factors that could have contributed to variation in metal concentration were soil, climate, and fertilization practices. Table VI1 compares the data from this study and other major surveys conducted by FDA or reported by other workers. Levels of Cd and P b found in this study are generally much lower than those previously reported. A variety of factors may be responsible for this: selection of relatively uncontaminated fields, careful sampling and handling, and laboratory equipment and practices that reduce contamination of samples during analysis. An important consideration in evaluating the values for Pb found in other studies is whether the P b in processed foods had been present when the crop was harvested from the field or had been added by canning, handling, packaging, or other food processing or distribution procedures. ACKNOWLEDGMENT
The contributions of the following individuals, who participated in the planning and evaluation of this program, are gratefully acknowledged: R. Daniels, Soil Conservation Service (SCS), USDA (retired), and R. Chaney, Agricultural Research Service, USDA, Washington, DC; K. Dotson, EPA, Cincinnati, OH; A. L. Page, University of California, Riverside. Soil scientists of the field staff of the SCS selected sites and collected and shipped all crop and soil samples.
Registry No. Cadmium, 7440-43-9; lead, 7439-92-1. Supplementary Material Available: Complete tabulation of individual data (with part 2), additional statistics, histograms, and probability (SAS computer printouts) (12 pages). Ordering information is given on any current masthead page. LITERATURE CITED Andersson, A.; Pettersson, 0. Swed. J . Agric. Res. 1981, 11, 49. Compliance Program Evaluation “Compliance Program Report of Findings, FY-77 Pesticides and Metals Program (7320.79)”; U S . Food and Drug Administration: Washington, DC, 1977. Compliance Program Evaluation “Compliance Program Report of Findings, Total Diet Studies-Adult (7305.003)”;U.S. Food and Drug Administration: Washington, DC, 1978. Council for Agriculture, Science, and Technology, Ames, IA, 1976, Report No. 64. Council for Agriculture, Science, and Technology, Ames, IA, 1980, Report No. 83. Falkoff, A. D.; Iverson, K. E. I B M J . Res. Deu. 1973, 17, 324. Fed. Regist. 1979a, 44 (179), 53438. Fed. Regist. 1979b, 44 (148), 44940. Holmgren, G. G. S.; Chaney, R. L.; Meyer, M. W.; Kubota, J.; Fricke, F. L. ”Soil Survey Investigations Report”; Soil Conservation Service,US. Department of Agriculture: Washington, DC, 1983. Jelinek, C. F.; Braude, G. L. J . Food Prot. 1978, 41, 476. Kaferstein, F. K. Zentralbl. Bakteriol., Parasitenkd., Infektionskr. Hyg., Abt. 1: Orig., Reihe B 1980, 171, 352. Kienholz, E. W.; Ward, G. M.; Johnson, D. E.; Daxter, J.; Braude, G.; Stern, G. J. Anim. Sci. 1979, 48, 735. Pfeilsticker, K.; Maskard, C. 2. Lebensm.- Unters. -Forsch. 1975, 158, 129. Reith, J. F.; Engelsma, J.; Van Ditmarsch, M. 2. Lebensm.-Unters. -Forsch. 1974, 156, 271. SAS “SAS User’s Guide”; SAS Institute: Cary, NC, 1979. SAS “SAS Technical Report P-115”;SAS Institute: Cary, NC, 1981. Satzger, R. D.; Clow, C. S.; Bonnin, E.; Fricke, F. L. J. Assoc. Off. Anal. Chem. 1982, 65, 987. Shacklette, H. T. “U.S. Geological Survey, Professional Paper 1178”;U.S. Government Printing Office: Washington, DC, 1980. Thomas, B.; Roughan, J. A.; Watters, E. D. J . Sci. Food Agric. 1972,23, 1493. Received for review March 18,1983. Accepted July 13,1983. The mention of proprietary products, materials, or trade names does not imply endorsement by the U S . Government.
Elements in Major Raw Agricultural Crops in the United States. 2. Other Elements in Lettuce, Peanuts, Potatoes, Soybeans, Sweet Corn, and Wheat Karen A. Wolnik, Fred L. Fricke, Stephen G. Capar,* George L. Braude, Milton W. Meyer, R. Duane Satzger, and Roy W. Kuennen Six raw agricultural crops (lettuce, peanuts, potatoes, soybeans, sweet corn, and wheat) were collected from fields in major U S . growing areas and were analyzed for Ca, Cu, Fe, K, Mg, Mn, Mo, Na, Ni, P, Se, and Zn. Statistical frequency distributions of some of the major elements were normal. In part 1 (Wolnik et al., 1983), the P b and Cd content of six major agricultural crops was reported based on a Food and Drug Administration, Cincinnati, Ohio 45202 (K.A.W., F.L.F., R.D.S., and R.W.K.), and Washington, DC 20204 (S.G.C. and G.L.B.), and Soil Conservation Service, US.Department of Agriculture, Washington, DC 20013 (M.W.M.).
large sampling and carefully controlled analytical program. While Cd and P b are toxic and obviously undesirable in food crops, other major and minor elements are of interest for different reasons. Several elements, such as Ca, Fe, K, Mo, Na, Ni, and P, are essential for human and animal health, and knowledge about their levels in different raw foods will provide information on the nutritional adequacy of diets. Others, such as Cu, Se, and Zn, though essential,
This article not subject to US. Copyright. Published 1983 by the American Chemical Society
J. Agric.
Some Elements in Major U S . Raw Agricultural Crops
Table I. Multielement Recovery and Results for Standard Reference Materialsa ____~ sweet corn peanuts amount amount NBS Spinach 1570 ele- added, recovery added, recovery, ment pg/g %, + SDd pg/g %, + SDC certified, pg/g results, pg/gd ~
Ca
cu Fe
K Mg Mn Mo Na Ni P Se Zn
Food Chem., Vol. 31, No. 6, 1983 1245
~
500 10 10 5000 500 10 10 400 10 1000 0.05 10
loo+2 98 ?: 2 loo+5
97 + 5 97 + 5 99 t 2 99+ 2 96 + 2 99 + 2 100 + 4 99 + 1 6 101 ?: 4
1 0 1 i: 2 101 + 3 99i. 7 1 0 3 f. 3 101 + 4 98+4 96 + 3
1000 10 10 5000 1000 10 10
f
f
100 f 103 + 99i. 102 f
10 2000 0.05 10
2 3 16 7
1 3 500 ?: 300 12+2 550 + 30 3 5 600 + 300
1 2 9 0 0 i. 300 11.8 r 2 530 i 11 35 200 + 1000 8600 t 200 165 * 3 < 0.25
f
165 + 6
f f
f
6z 5500 + 200
5.51 t 0.32 5300 + 70
f
f
50+ 2
49.8
t
1.3
NBS Wheat Flour 1567 certified, pg/g
results, pg/ge
190 i. 1 0 2.0 + 0.3 18.3 + 1.0 1360 f 40
1 9 6 f. 3 2.03 i. 0.05 18.6 + 1.5 1320 t 40 401 t 8 8.42 + 0.23 0.396 ? 0.05
f
8.5 + 0.5 0.4g 8.0 i 1.5 0.189
f 1.1i. 0.2 10.6 t 1 . 0
f f
1390 + 30 0.90 t 0.05 11.0 + 0.3
Mean Mean of 21-30 recovery determinations. Mean of 29-30 recovery determinations. a Based on dry weight. of 1 4 determinations. e Mean of 29 determinations, except for Se, where mean of 50 determinations. Not determined. e. Noncertified value.
Table 11. Elements in Lettucea pg/g wet weight
mean
median
minimum
maximum
cv
210 0.26 3.0 1700 83 1.8 0.013 74 220 0.0016 1.9 0.0415
170 0.24 2.2 1500 71.5 1.25 0.0067 66 21 5 0.00066 1.8 0.040
110 0.065 1.3 900 42.0 0.23 < 0.0039 14 130
