METAL DETERMINATION IN VEGETABLESTim Cumming

Jesse Diehl

Meg Dailey

WHY EAT VEGETABLES?

Rich in vitamins and minerals Nutritious Fiber May reduce the risk of diseases, including

heart disease and high blood pressure Help you feel energized and healthy

OUR PROJECT

We were looking for minerals in vegetables, both frozen and organic

The vegetables we looked at were; cauliflower, broccoli, carrots, green beans and spinach

We were expecting to find Fe What we found was Ca, K, Ag, Fe and Cu

HOW DID WE GO ABOUT THIS?

Determine what vegetables to test Run samples on the XRF Determine what elements to look for on the

ICP Turn the vegetables into liquid Run standard and samples on the ICP

THE XRF AND THE ICP

XRF DATA SAMPLE

Organic Spinach

Analyte Result

K 58.864%

Ca 30.134%

Si 3.740%

S 3.196%

Fe 2.158%

Cu 0.719%

Zn 0.604%

Hf 0.584%

XRF DATA ANALYSIS

Only found Fe in the spinach Vegetables mostly contained Ca, K, and Cu Kept Fe because it was what we were

originally looking for Ag was found in the carrots and the frozen

spinach Curious, we decided to look for Ag, too

ICP

Decided to make standard of 0.1, 0.5, 2.0, 4.0, 6.0, 8.0, and 10.0 ppm

Standards contained Ag, Fe, Cu, Ca, and K Standards were made from 1000 ppm

standard metal solutions Vegetable samples were made from 10 mL of

filtered sample diluted to 100 mL with distilled water

ICP STANDARD DATA

0 2 4 6 8 10 120

20000

40000

60000

80000

100000

120000

f(x) = 10618.0153939491 x + 10.3530311122449R² = 0.999999999429391

Silver Calibration Curve

Concentration (ppm)

Inte

nsit

y (

c/s

)

ICP STANDARD DATA

0 2 4 6 8 10 120

2000000

4000000

6000000

8000000

10000000

12000000

14000000

f(x) = 1206425.15625218 x + 17708.486239898R² = 0.999999999993598

Calcium Calibration Curve

Concentration (ppm)

Inte

nsit

y (

c/s

)

ICP STANDARD DATA

0 2 4 6 8 10 120

10000

20000

30000

40000

50000

60000

70000

80000

90000

f(x) = 7969.04309217959 x + 33.2936003083705R² = 0.999999999797487

Copper Calibration Curve

Concentration (ppm)

Inte

nsit

y (

c/s

)

ICP STANDARD DATA

0 2 4 6 8 10 120

20000

40000

60000

80000

100000

120000

140000

160000

f(x) = 14271.7082559596 x + 26.8858500123461R² = 0.999999999630934

Iron Calibration Curve

Concentraion (ppm)

Inte

nsit

y (

c/s

)

ICP STANDARD DATA

0 2 4 6 8 10 120

100000

200000

300000

400000

500000

600000

700000

800000

f(x) = 61777.4862383921 x + 1085.49811239008R² = 0.999999999900196

Potassium Calibration Curve

Concentration (ppm)

Inte

nsit

y (

c/s

)

ICP DATA

Concentration (ppm)

Carrot Cauliflower

Broccoli Green Beans

Spinach

Ag Organic 0.17041 0.074390 0.019076 0.015834

0.016812

Ag Frozen 0.017997

0.11988 0.18123 0.019249

0.068803

Ca Organic 7.8494 3.4895 0.89433 -0.013705

-0.014020

Ca Frozen -0.013448

5.1966 7.6079 6.7422 1.3420

Cu Organic

0.10106 0.040245 0.0295989

0.007749

0.009825

Cu Frozen 0.007250

0.045495 0.027968 0.032581

0.027537

Fe Organic 0.42855 0.090389 0.042881 0.005511

0.005003

Fe Frozen 0.004836

0.040012 0.10675 0.046718

0.070272

K Organic 89.503 71.976 17.185 2.5576 3.9217

K Frozen 1.9172 62.624 71.585 45.551 46.891

ICP DATA ANALYSIS

All vegetables showed trace amounts of Ag, Cu, and Fe

Organic carrots showed the highest concentration of Fe, K, and Ca

Frozen broccoli showed the highest concentration of Ag

Frozen broccoli, spinach, and green beans showed higher concentrations of Ca and K than the organic vegetables

Believe that the silver was from pesticides What vegetable depends on whether organic

is better than frozen

BENEFITS OF METALS

Calcium is needed for healthy bones, healthy teeth, and functioning of nerves, glands, and muscles

Iron is needed for healthy blood and functioning of cells

Potassium is needed to maintain healthy blood pressure

SOURCES

http://www.fruitsandveggiesmorematters.org/top-10-reasons-to-eat-more-fruits-and-vegetables

http://www.fruitsandveggiesmorematters.org/key-nutrients-in-fruits-and-vegetables

http://www.epa.gov/oppsrrd1/REDs/old_reds/silver.pdf

http://www.epa.gov/opp00001/biopesticides/ingredients/factsheets/factsheet_072503.htm