Chlorophylls, determination

Moran, R. and Porath, D., Chlorophyll determination in intact tissues using N,N-dimethytformamide. Plant Physiol., 65, 478, 1980. 

Bjarnborg [464] has studied shipboard methods of continuous recording of in vivo chlorophyll fluorescence and extraction-based chlorophyll determinations in Swedish archipelago waters. 

Maerker, M. and Szekielda, K.H., 1976. Chlorophyll determination of phytoplankton a comparison of in vivo fluorescence with spectrophotometric absorption. J. Cons. Int. Explor. Mer., 36 (3) 217-219. 

The reference method for chlorophyll determination is ISO 10519 1997 chlorophyll is measured spectrophotometrically after extraction, results being expressed as mg/kg (or ppm). NIRS is a rapid method that could be used to measure the chlorophyll content. Chlorophyll content is not truly measured in the NIR range. The best wavelengths used to measure chlorophyll are in the 650-700 nm area. 

Cells were grown at 30 C as described earlier (Binder and Bachofen, 1979). The membrane preparation as well as the isolation of the multiple subunit reaction center was done according to Nechushtai et al. (1983). SDS-PAGE was done as described by Wiemken et al. (1981). If not stated otherwise the samples for the SDS-PAGE were treated with 2% SDS for 20 min at 60 (SDS to chlorophyll ratio 20 1). Protein determination was done according to Peterson (1977 and chlorophyll determination aft r extraction with 80% acetone using an extinction coefficient of 80.04 mM cm at 663 nm. 

Chlorophenols, determination of 102-104, 285, 350 Chlorophylls, determination of 104-106,203-205, 248-260 Chromatographic detectors, atomic absorption 32-33 fluorescence 29-31 infrared 31, 32 inductively coupled plasma atomic emission 33-35 Raman 31, 32 visible 29 Chromate, determination of 60-65 Chromium, determination of 166, 234, 235,477-481... 

Willstatter s most important work for which he won the 1915 Nobel Prize in chem istry was directed toward determining the structure of chlorophyll... 

Abridged Spectrophotometry. It is not always necessary to obtain complete spectrophotometric curves in order to measure physical characteristics related to color. The procedure can often be considerably simplified by some abridged form of spectrophotometry. Measurements may be made only at critical wave lengths or wave-length bands, as has been done to determine chlorophyll degradation (1, 8). In such instances the real problem that faces the investigator is to establish the critical wave lengths. 

The chemical structure of dinoflagellate luciferin was found to be a tetrapyrrole, possibly derived from chlorophyll (Nakamura et al., 1989). The luciferase of G. polyedra was cloned (Bae and Hastings, 1994). Recently, the crystal structure of the third domain of the luciferase was determined (Schultz et al., 2005). 

Recently, the ocean-basin distribution of marine biomass and productivity has been estimated by satellite remote sensing. Ocean color at different wavelengths is determined and used to estimate near-surface phytoplankton chlorophyll concentration. Production is then estimated from chlorophyll using either in situ calibration relationships or from empirical functional algorithms (e.g., Platt and Sathyendranth, 1988 Field et al., 1998). Such studies reveal a tremendous amount of temporal and spatial variability in ocean biological production. 

Tan, Y.A., Low, K.S., and Chong, C.L., Rapid determination of chlorophylls in vegetable oils by laser-based fluorometry, J. Sci. Food Agric., 66, 479, 1994. Bhattacharya, D. and Medlin, L., Algal phylogeny and the origin of land plants, Plant Physiol., 116, 9, 1998. 

Mangos, T.J. and Berger, R.G., Determination of major chlorophyll degradation products, Z. Lebensm. Unters. Forsh. A, 204, 345, 1997. 

Ferruzzi, M.G. et al.. Antioxidant and antimutagenic activity of dietary chlorophyll derivatives determined by radical scavenging and bacterial reverse mutagenesis assays, J. Food ScL, 67, 2589, 2002. 

Because a chlorophyll molecule contains a closed circuit of ten conjugated double bounds to absorb light, spectrophotometric (UV-Vis) and fluorometric measurements are satisfactory to identify and estimate amounts of chlorophyll a and chlorophyll b, usually the only ones present in fresh plant extracts. The basis of numerous spectrophotometric determinations reported in literature is that chlorophylls strongly absorb at 500 to 700 nm in the visible region and show a large typical band around 400 nm. 

Due to the high mass, low volatility, and thermal instability of chlorophylls and derivatives, molecular weight determination by electron impact (El) MS is not recommended. Desorption-ionization MS techniques such as chemical ionization, secondary ion MS, fast-atom bombardment (FAB), field, plasma- and matrix-assisted laser desorption have been very effective for molecular ion detection in the characterization of tetrapyrroles. These techniques do not require sample vaporization prior to ionization and they are effective tools for allomerization studies. 

The development and reports of methods for colorless chlorophyll derivative (RCCs, FCCs, and NCCs) analysis are relatively recent and the structures of the compounds are being elucidated by deduction from their chromatographic behaviors, spectral characteristics (UV-Vis absorbance spectra), mass spectrometry, and nuclear magnetic resonance analysis. The main obstacle is that these compounds do not accumulate in appreciable quantities in situ and, moreover, there are no standards for them. The determination of the enzymatic activities of red chlorophyll catabolite reductase (RCCR) and pheophorbide a monoxygenase (PAO) also helps to monitor the appearance of colorless derivatives since they are the key enzymes responsible for the loss of green color. ... 

Ergun, E. et al.. Simultaneous determination of chlorophyll a and chlorophyll b by derivative spectrophotometry. Anal. Bioanal. Ghent., 379, 803, 2004. 

Porra, R.J., Thompson, W.A., and Kriedemann, P.E., Determination of accurate extinction coefficients and simultaneous equations for assaying chlorophylls a and b extracted with four different solvents verification of the concentration of chlorophyll standards by atomic absorption spectroscopy, Biochim. Biophys. Acta, 975,384, 1989. 

Mantoura, R.F.C. and Llewellyn, C.A., The rapid determination of algal chlorophyll and carotenoid pigments and their breakdown products in natural waters by reversed-phase high-performance liquid chromatography, A a/. Chim. Acta, 151, 297, 1983. 

Tkachuk, R. et ah. Determination of chlorophyll in ground rapeseed using a modified near infrared reflectance spectrophotometer, J. Am. Oil Chm. Soc., 65, 381, 1988. 

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