Kangkung termasuk sayuran yang banyak digemari, yang mudah tumbuh ditempat berair ataupun di dekat sungai, dan karena itu banyak ditanam di dekat sungai dan disirami dengan air sungai tersebut. Jika sungai tercemar dengan logam berat, maka kemungkinan besar tanaman yang tumbuh disitu juga tercemar. Suatu penelitian terhadap kangkung yang ditanam di media yang tercemar oleh Pb membuktikan bahwa kangkung tersebut juga mengandung Pb. Untuk mengetahui sejauh mana perebusan dapat mengurangi kandungan Pb dalam kangkung dilakukan penelitian dengan berbagai cara perebusan. Pada penelitian ini digunakan kangkung darat (Ipomoea reptans) sebagai sampel, dan ditanam secara hidrofonik, serta disiram dengan larutan Multigrow Complete Plant Food (2000 mg/L) dan larutan Pb (2 mg/L dua kali sehari. Kangkung dipanen pada usia 54 hari, kemudian daun dan batangnya direbus dengan berbagai cara. Perlakuan I: direbus dengan air saja, perlakuan II: direbus dengan penambahan NaCl, perlakuan III: direbus dengan penambahan asam asetat 25%. Perlakuan IV: sampel yang tidak direbus, sebagai kontrol. Untuk mengukur kandungan Pb digunakan alat Inductively Coupled Plasma Spectrometer (ICPS) Fison 3410+. Penambahan asam asetat ternyata tidak mengurangi kandungan Pb dalam daun dan batang kangkung sebanyak yang disebabkan oleh perebusan tanpa penambahan NaCl atau asam asetat, ataupun perebusan dengan penambahan NaCl. Perbedaan ini sangat signifikan pada batang kangkung, sedangkan pada daun tidak signifikan.

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Study on The Content of Pb in Twigs And Leaves of Kangkung (Ipomoea reptans Poir) Boiled With The Addition of NaCl And Acetic Acid. Kangkung is a kind of favorable vegetables that used to grow near a river, and is cultivated and watered with water from the river. If the river is polluted by heavy metals, there is a risk that the plant is contaminated too. A study on the content of Pb in kangkung planted in Pb contaminated media has been conducted, and it was proven that Pb was found in the plant. Land kangkung (Ipomoea reptans) was used as sample, and was planted in hydrophonic media, and watered with Multigrow Complete Plant Food (2000 mg/L) and Pb solution (2 mg/L) twice a day. Samples were taken based on the age of 54 days, then the twigs and leaves were boiled in different ways: I. Boiled with no addition, II. Boiled with addition of NaCl , and III. Boiled with addition of acetic acid. IV. Unboiled sample as the control. Inductively Coupled Plasma Spectrometer (ICPS) Fison 3410+ was used to measure the Pb content. It was shown that boiling the kangkung reduced the Pb content in the leaves as well as in the twigs; however, the acetic acid addition showed the least effect. In the leaves the three different ways of boiling did not show significant different, while in twigs the different was significant.