Spots yellow/brown

Leaves spotted, yellowed, browned, or wilted roots, stems, or leaves with rotted spots. 

Chlorosis and abscission brown spotting yellowing of veins... 

Another reversal location method is to expose the TLC plate to iodine vapour in a closed chamber that contains some iodine crystals. Iodine is lipophilic and accumulates in hpophihc sample spots, showing a brown color on a pale yellow-brown background. The same result is obtained by spraying with an iodine solution (250 mg iodine dissolved in 100 ml of heptane). In nearly all cases, this iodine accumulation is totally reversible without altering the sample, because outside the closed chamber iodine evaporates quickly from the plate. Caution should be taken with this iodine treatment in the case of unsaturated compounds because iodine vapor can react with double bonds [16]. 

Alopecia Bulla Chloasma Deficiency of hair Large blister or vesicle fdled with serous fluid Cutaneous discoloration occurring in yellow-brown patches and spots... 

Iodine vapour Place the dried plate in a sealed tank containing a few iodine crystals Dark yellow-brown spots appear within a few minutes where lipids have absorbed the iodine. Unsaturated lipids are more intensely stained. Glycolipids do not stain significantly... 

Violet spots Gray-brown spots Red/brown spots Yellow fluorescence under UV Red colors when exposed to ammonium hydroxide Variety of spots... 

Gibbs Yellow-brown spots changing to blue-orange upon exposure to ammonia 119... 

Silver nitrate/ammonium Yellow-brown spots 1... 

Silver nitrate-ammonium hydroxide-sodium chloride A mixture of silver nitrate (0.05 M)/ ammonium hydroxide (5%) is sprayed on the plate, followed by drying and further spraying with 10% aqueous sodium chloride to yield yellow/brown spots. 

Organophosphate. For the estimation of phosphoric acid esters, the developed plate is sprayed with 0.25% solution of palladium chloride in 0.1 N HC1 and dried in air. After exactly ten minutes, the area of the yellow-brown colored spot developed is measured and compared with that of the spots of standard insecticide solutions run alongside. 

Acidified potassium permanganate solution. Yellow-brown spots on a violet background are given by drugs with unsaturated aliphatic bonds. 

Acidified potassium permanganate solution. Yellow-brown spots on a violet badcground are givoi by drugs with unsaturated aliphatic bonds, e.g. quinalbarbitone. This solution may be used to overspray a plate which has been previously sprayed with mercurous nitrate spray. 

Hence, hydrochlorides should preferably be examined in potassiiun chloride. Bromide may be oxidised to bromine by some compounds, particularly stiong oxidising agents, d this may lead to a disk becoming either discolowed or having yellow-brown spots. 

Leaves and flowers deformed, yellowish small, tarlike spots on undersidies. Cause Lace bugs. These small pests with lacy wings cause yellow-brown le lf spots. Dark brown droppings on lower leaf surfaces confirm their activity. Remove debris in spring and fall to deter overwintering. For severe problems, spray superior oil, insecticidal soap, or pyrethrin. 

Leaves with yellow-brown spots or blotches leaves die and turn brittle. Cause Foliar nematodes. These microscopic roundworms overwinter in soil or plant debris, then travel up a plant s stem in the film of water created by spring rains, entering the lower leaves... 

Leaves with yellow, brown, or black spots. Cause Fungi. Several fungi cause spots on leaves. As spots enlarge, entire leaves may wither. Remove and destroy infected foliage ... 

If chromatograms have been developed in acid solvents, it is more satisfactory to make sheets alkaline by spraying with 10% aqueous sodium carbonate solution and, when dry, applying reagent. Reaction is immediate and all spots appear blue (except red for proline) on a yellow-brown background. 

As shown in Fig. 4.8, /3-CD and Mal-/3-CD can be well separated by TLC. /1-CD exhibits a yellow-brown spot, Mal-/3-CD exhibits two light yellow spots... 

Fenbuconazole (Table 17.11) is a triazole fungicide intended for use as an agricultural and horticultural fungicide spray for the control of leaf spot, yellow and brown rust, powdery mildew and net blotch on wheat and barley and apple scab, pear scab and apple powdery mildew on apples and pears. Fenbuconazole was already presented to the public in 1988 by Driant et al. [43]. 

Aminodeoxyhexoses - intense yellow-brown spots aminodideoxyhexoses (e.g. fucosamine) - orange-yellow amino acids - grey, red, or purple... 

Spraying with cone. H2SO4 and heating to 110° C the spots are yellow brown in daylight only oxy-Tc shows fluorescence (yellow) in UV light. 

Pbey and co-workers [70] have separated glycerol hRf 38) from ethylene glycol (hi / 45) on normal silica gel G layers, using butanol-water (90 + 10) the separation may be improved by impregnation with O.IN boric acid. They used dichromate-sulphuric acid (Rgt. No. 46) for detection, obtaining white spots on a yellow-brown background. 

The values of the nitro-, dirdtro- and trinitrotoluene isomers and of some oxidation and reduction products of a-(2,4,6-)trinitro-toluene (= 8t) are referred to this last named compound. Ethyl acetate-petrol ether (15 + 85) and 1,2-dichloroethane-petrol ether (25 + 75) were the solvents used in the 1st and 2nd directions respectively. The-substances were visualised by spraying with the 4-diethylaminobenz-aldehyde reagent, yielding yellow, brown or red spots (Fig. 187). 

The layer is sprayed with I, dried and then sprayed with II. It is then exposed to daylight until the yellow-brown spots have attained maximum colour intensity. 

In the Kf- range from 0.60 up to =0.80 appear with yellow brown colour linoleic acid (T3), oleic acid (T5) and the phytosterol P- sitosterol (T2). Saccharose was identified at iy=0.16 (T4). In the Rf- range Rf= 0.15 till Kf= 0.50 the three dark brown and pink brown spots might be identical with mono-, di- and triglycoside of sesaminol. 

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