Thymol Reagent

Q. Thymol Reagent is prepd, right before use, by mixing crystalline thymol with coned HgSC. For testing an unknown substance... 

III. Treatment with Thymol Reagent. See item Q under colorimetric reagents and Charts A B given in this section... 

Quantitative tests for RDX are described in this Volume under Cyclotrimethylenetrinitramine (RDX), Analytical Procedures Xy Alkali Solubility Test. Shake ca 0,5g of the sample for 2mins in a test tube with 5ml of 10% NaOH soln, filter and acidify the filtrate with coned HCl, Cool the tube under tap w, and rub the inside of the tube with a glass rod, A white ppt, appearing after about 5mins, is a positive test for EDNA and its presence can be confirmed by treating the sample with Thymol Reagent - a brown color is a positive test for EDNA (See also Chart B)... 

Study of the mechanism of Madagan s thjrmol turbidity test (42, 49, 218) indicates some alteration in the amount or type of phospholipide bound to 3-globulins in hepatitis serum. Cohen and Thompson (49) found that addition of thymol reagent causes a marked decrease in the... 

Thiol compounds 252, 254 Thione compounds 252, 254 Thiosemicarbazides, N-aryl- 248 Thiourea 107, 246,254, 269, 337 -, derivatives 322, 323 Thorium cations 144 Threonine 246 Thymol 153, 197, 198 -, derivatives 288 Tigogenin 59, 195 -, acetate 63 Tigogenone 59,60 Tillmans reagent 256 Tin, cations 144,311,398 -, organic derivatives see Organotin compounds... 

Spengler and Jumar [90] used a spectrophotometric method and thin layer chromatography to determine carbamate and urea herbicide residues in sediments. The sample is extracted with acetone, the extract is evaporated in vacuo at 40°C and the residue is hydrolysed with sulphuric acid. The solution is made alkaline with 15% aqueous sodium hydroxide and the liberated aniline (or substituted aniline) is steam distilled and collected in hydrochloric acid. The amine is diazotized and coupled with thymol, the solution is cleaned up on a column of MN 2100 cellulose power and the azo-dye is determined spectrophotometrically at 440nm (465nm for the dye derived from 3-chloro- or 3.4-dichloroaniline) with correction for the extinction of a reagent blank. 

Another non-specific color reagent for RDX and HMX is a solution of thymol in concentrated sulfuric acid [3, 56, 59]. It produces a typical red color. Positive results are also obtained with non-explosive compounds such as sugars and aldehydes. 

All this can mean that, if the aq soln of unknown sample is colorless in Test 2, no ppt with,Nessler s reagent, no color with ethylene-diamine in Test 2, deep blue color with DPhA in Test 3 and green a>lor with thymol soln in Test 4, it could be NG... 

Methylthymol blue and methylxylenol blue, prepared by the Mannich reaction from thymol-sulfonphthalein and p- xylenol blue respectively, have been intensively studied and resemble xylenol orange in many respects. If only one chelating group is introduced into cresol red, semi-xylenol orange results which is a common contaminant in XO and proves to be a more sensitive reagent for zirconium. 

The most sensitive analysis was achieved with pentafluorobenzoate, which permits up to 10 12 g of thymol to be determined. Clarke et al. [74] compared the characteristics and ECD responses of acyl derivatives of amines. Table 4.7 shows some of their results. It follows that a different type of acyl derivative is suitable for each type of amine and at the same time other characteristics, which are not reported in the table, must also be taken into consideration. TFA derivatives have better chromatographic characteristics than chloroacetates and usually are preferred, despite their lower responses. The highest sensitivity was obtained by Clarke et al. for HFB derivatives. Other workers [75] drew attention to the dependence of the responses of haloacyl derivatives on the detector temperature. Its significance can be particularly important in trace analysis, when it is necessary to work at the maximal sensitivity of the detector. In each instance when an acyl derivative is used a compromise must be found among the sensitivity required, volatility of the derivatives, reagent availability and other factors. 

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