Penetapan Kadar Kalium, Kalsium, Natrium dan Magnesium pada Selada Air (Nasturtium officinale R.Br.) Segar dan Direbus Secara Spektrofotometri Serapan Atom

PENETAPAN KADAR KALIUM, KALSIUM, NATRIUM, DAN
MAGNESIUM PADA SELADA AIR (Nasturtium officinale R.Br.)
SEGAR DAN DIREBUS SECARA
SPEKTROFOTOMETRI SERAPAN ATOM
ABSTRAK
Selada Air (Nasturtium officinale R.Br.) adalah tumbuhan asli di Eropa,
Asia Barat, Ethiopia dan sekarang juga telah ditanam atau tumbuh di Indonesia.
Selada air memiliki manfaat dan gizi yang sangat baik. Sayuran daun ini memiliki
kandungan mineral dan vitamin yang cukup lengkap. Sayuran ini dapat dimakan
segar ataupun direbus. Sebagian besar nutrisi selada air hilang saat dimasak.
Tujuan dari penelitian ini adalah untuk mengetahui adanya perbedaan kandungan
kalium, kalsium, natrium, dan magnesium pada selada air segar dan direbus.
Penetapan kadar dilakukan dengan menggunakan spektrofotometer
serapan atom (SSA) dengan nyala udara-asetilen pada panjang gelombang untuk
kalium, kalsium, natrium, dan magnesium berturut-turut 766,5 nm, 422,7 nm,
589,0 nm, dan 285,2 nm. Keuntungan dari metode ini adalah sensitif dan selektif.
Hasil penelitian menunjukkan bahwa kadar kalium pada selada air segar
sebesar (481,7954 ± 2,4003) mg/100g dan pada selada air rebus sebesar (142,6566
± 0,7998) mg/100g. Kadar kalsium pada selada air segar adalah (74,9802 ±
0,1389) mg/100g dan pada selada air rebus sebesar (70,8216 ± 0,2755) mg/100g.
Kadar natrium pada selada air segar adalah (11,6992 ± 0,1660) mg/100g dan pada

selada air rebus sebesar (8,4131 ± 0,0456) mg/100g. Kadar magnesium pada
selada air segar sebesar (15,6874 ± 0,1565) mg/100g dan pada selada air rebus
sebesar (8,7205 ± 0,0677) mg/100g. Hasil statistik uji beda rata-rata kadar mineral
antara selada air segar dan selada air rebus dengan menggunakan distribusi F,
menyimpulkan bahwa terdapat perbedaan yang signifikan kadar kalium, kalsium,
natrium, dan magnesium antara selada air segar dan selada air rebus dengan
tingkat kepercayaan 99%.

Kata kunci : Selada Air Segar, Rebus, Kalium, Kalsium, Natrium, Magnesium,
Spektrofotometer Serapan Atom

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Universitas Sumatera Utara

DETERMINATION OF POTASSIUM, CALCIUM, SODIUM,
AND MAGNESIUM IN WATERCRESS (Nasturtium officinale
R.Br.) FRESH AND BOILED WITH
ATOMIC ABSORPTION SPECTROPHOTOMETRY
ABSTRACT
Watercress (Nasturtium officinale R.Br.) is a native plant in Europe, West

Asia, Ethiopia and nowadays also has been planted or grows in Indonesia.
Watercress has its benefits and excellent nutrition. This vegetable contains
minerals and vitamins quite complete. This vegetable can be eaten fresh or boiled.
Most of the nutrients in watercress lost when it is boiled. The aim of this study is
to determine the differences in the content of potassium, calcium, sodium, and
magnesium in the fresh and boiled watercress.
The determination of these minerals was measured using the atomic
absorption spectrophotometer with air-acetylene flame at the wavelength for
potassium, calcium, sodium, and magnesium were 766.5 nm, 422.7 nm, 589.0 nm,
and 285.2 nm respectively. The advantage of this method is sensitive and
selective.
The results showed that the level of potassium in fresh watercress was
(481.7954 ± 2.4003) mg/100g and in boiled watercress was (142.6566 ± 0.7998)
mg/100g. The level of calcium in fresh watercress was (74.9802 ± 0.1389)
mg/100g and in boiled watercress was (70.8216 ± 0.2755) mg/100g. The level of
sodium in fresh watercress was (11.6992 ± 0.1660) mg/100g and in boiled
watercress was (8.4131 ± 0.0456) mg/100g. The level of magnesium in fresh
watercress was (15.6874 ± 0.1565) mg/100g and in boiled watercress was (8.7205
± 0.0677) mg/100g. Statistically results of different test average content of
minerals between fresh watercress and boiled watercress using the F distribution,

concluded that there are significantly difference in potassium, calcium, sodium,
and magnesium levels between fresh watercress and boiled watercress by
confidency interval 99%.

Keywords : Fresh Watercress, Boiled, Potassium, Calcium, Sodium, Magnesium,
Atomic Absorption Spectrophotometer

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Universitas Sumatera Utara