Chlorophyll decomposition in Skeletonema costatum: a problem in chlorophyll determination of water samples

Chlorophyll Turnover in Skeletonema costatum, a Marine Plankton Diatom.

[(3)H]- and delta-[(14)C]Aminolevulinic acids were incorporated into the chlorophylls of Skeletonema costatum, a marine plankton diatom. In the stationary phase of growth, the tetrapyrrole-based pigments reached steady-state labeling after 10 hours. Under conditions of exponential cell division and chlorophyll accumulation, (3)H was rapidly lost from the labeled chlorophylls and was replaced wi...

Formation of water-chlorophyll clusters in dilute samples of chlorophyll-a in ether at low temperature.

Simultaneously measured absorption (ABS) and magnetic circular dichroism (MCD) spectra of the Q-bands of chlorophyll-a (Chl-a) in ether over 150-186 K reveal that the species that forms at low temperature is a chlorophyll hydrate rather than a diether complex. We have recently proposed a new assignment paradigm for the spectra of chlorophillides which, for the first time, quantitatively account...

Chlorophyll a Determination: Improvements in Methodology

Nitrate Utilization by the Diatom Skeletonema costatum

Nitrate uptake has been studied in nitrogen-deficient cells of the marine diatom Skektowema costatum. When these cells are incubated in the presence of nitrate, this ion is quickly taken up from the medium, and nitrite is excreted by the cells. Nitrite is excreted following classical saturation kineffcs, its rate being independent of nitrate concentration in the incubation medium for nitrate co...

application and construction of carbon paste modified electrodes developed for determination of metal ions in some real samples

ساخت الکترودهاِی اصلاح شده ِیکِی از چالشهاِی همِیشگِی در دانش شیمِی بوِیژه شیمِی تجزیه مِی باشد ،که با در نظر گرفتن سادگِی ساخت، کاربردی بودن و ارزان بودن روش مِی توان به باارزش بودن چنِین سنسورهاِی پِی برد.آنچه که در ادامه آورده شده به ساخت و کاربرد الکترودهاِی اصلاح شده با استفاده از نانو ذرات در اندازه گِیرِی ولتامترِی آهن وکادمِیم اشاره دارد. کار اول اختصاص دارد به ساخت الکترود خمِیر کربن اصلاح شده با لِیگاند داِ...