Trichloroacetic acid (TCA) (60 ml o

Trichloroacetic acid (TCA) (60 ml of 6%) was used for fish
sample extraction purposes. Nash’s Reagent (Nash, 1953) was
used as an indicator to detect the absorbance of formaldehyde.
Fifteen g ammonium acetate was diluted in a 100 ml
Erlenmeyer flask with an addition of 0.3 ml of acetyl acetone
and 0.2 ml of acetic acid. Nash’s Reagent is light sensitive and
was kept in dark-glass reagent bottle at all time. A 0.1N
potassium hydroxide (KOH) and 0.1N hydrochloric acid (HCl)
was used to adjust the pH of the distillate to be in range of 6.0
to 6.5 by a pH meter.

The standard curve was obtained by plotting absorbance of
known formaldehyde concentration (viz. 0.838, 1.68, 2.51,
3.35 and 5.03 ppm) from a stock solution of formaldehyde
having 6.2% concentration (Fig. 1).

Results (Indonesian) 1:

Asam trikloroasetat (TCA) (60 ml 6%) digunakan untuk ikantujuan ekstraksi sampel. Nash Reagent (Nash, 1953) adalahdigunakan sebagai indikator untuk mendeteksi absorbansi formaldehida.Lima belas g amonium asetat diencerkan dalam 100 mlLabu Erlenmeyer dengan tambahan 0.3 ml asetil asetondan 0.2 ml asam asetat. Nash Reagent adalah sensitif terhadap cahaya dandisimpan dalam botol kaca gelap reagen sama sekali waktu. 0.1NKalium hidroksida (KOH) dan 0.1N asam klorida (HCl)digunakan untuk mengatur pH distilat harus dalam kisaran 6.0untuk 6,5 oleh pH meter.Kurva standar diperoleh dengan merencanakan absorbansi dariformaldehida dikenal konsentrasi (viz. 0,838 1,68, 2.51,3.35 dan 5.03 ppm) dari saham larutan formaldehidamemiliki 6,2% konsentrasi (Fig. 1).