Common adulterants, detection

System (8) has been described for quantitation of corticosteroids as common adulterants in local drugs [156]. The sample is extracted from its matrix by methanol, and the resulting supernatant layer subjected to the HPLC analysis. The column used was an ODS-Zorbax column (25 cm x 4.6 mm), and the mobile phase 7 2 11 acetonitrile-methanol-aqueous 1% phosphoric acid. An eluent flow rate of 0.8 mL/min was used, and the analyte detection was performed using the UV absorbance at 240 nm. The calibration graph was found to be linear in the ranges of 1-15 pg/mL for betamethasone, 0.5-20 pg/mL for prednisolone, and 1-30 pg/mL for cortisone acetate. 

Oil of Turpentine.—This is a common adulterant for the volatile oils and is not always easy to detect. In most cases use is made of the specific gravity, fractional distillation and rotatory power, and the characters of oil of turpentine are described in Chapter IX (see also Oil of Lemon). 

Fig. 7.6. Separation of heroin and some common adulterants and contaminations Column amino-propyl bonded silica (S5NH.)(Phase-Sep) (250x4 mm ID), mobile phase acetonitrile - 0.005 M tetrabutylammoniurn phosphate (85 15), flow rate 1 ml/min, detection UV 284 nm. Peaks 1, noscapine 2, papaverine 3, caffeine 4, heroin 5, acetylcodeine 6, 6-0-acetyl-morphine 7, codeine 8, strychnine 9, morphine, (Reproduced with permission from ref. 93, by the courtesy of Journal Chromatographic Science)...

In forensic toxicology, the term "adulterant" has a different meaning. An adulterant is something added to a urine sample to mask or otherwise defeat the detection of another substance. Bleach is a common adulterant that will cause many screening tests to fail. As a result, it is sometimes necessary to test a sample for the presence of adulterants as well as for the presence of taiget analytes. 

Adulterants and Diluents Adulterants and diluents added to a batch can provide useful information regarding batches and groups. Common adulterants in heroin are acetaminophen (referred to as paracetamol outside of the United States), caffeine, and lidocaine, all of which chromatograph well and can be detected simultaneously with the heroin. Diluents tend to be highly variable. Many are hard to identify during routine analysis, since some are removed in the sample preparation steps. Even if a dUuent can be isolated, its identification often requires more time than can be spared in routine cases. Sometimes a quick microscopic examination of residues is sufficient to identify starches... 

Street drugs sometimes contain adulterants added to increase the volume of drug perceived to be purchased. A case study reports atrioventricular junctional arrhythmia caused by quinine/quinidine added to heroin which was subsequently intravenously injected [24 ]. The authors report that a normal urine toxicological screening assay would not detect the adulteration, and that physicians should be aware of common adulterants. 

The oil is frequently adulterated with small quantities of castor oil and other oils. These adulterants present no difficulty when present in appreciable amounts, but when present in small quantity are exceedin y difficult to detect. Oils which only just satisfy the minimum requirements as to solubility, specific gravity, optical rotation, and santalol value should be regarded with considerable suspicion. Glyceryl acetate is sometimes used as an adulterant, and is detected by the high ester value of the sample (for which see Vol. II.). Benzyl alcohol is also sometimes used, but this will be indicated by an abnormally high santalol value and also by the distillation results. With pure sandal oil nothing distils below 280" at ordinary pressure (or 150 at 14 mm.), whilst benzyl alcohol distils at a much lower temperature. Cedar-wood oil is indicated by its insolubility in 70 per cent, alcohol, by its low santalol value, and by its high optical rotation. Further, a considerable distillate is obtained below 280 . The so-called West Indian sandal oil (q.v.) is also a somewhat common adulterant, which is easily detected by the alteration of all the constants of the oil, as well as by its decreased solubility and santalol value . 

Melting and Solidifying-Points—Boiling-Point and Distillation— Determination of Esters—Determination of Alcohols— Tables for the Calculation of Esters and Alcohols—Separate DMermination of Citronellol in Presence of Gwaniol—Determination of Aldehydes and Ketones— Miscellaneous Processes—Determination of Phenols—Detection of Chlorine—Determination of Hydrocarbons—Detection of some Common Adulterants. 

Sandalwood Oil. Benzyl alcohol is a common adulterant, one part being equivalent to two parts of santalol it can be detected by heating the oil with potassium dichromate and dilute sulphuric acid in a test-tube immersed in a water-bath, the odour of benzaldehyde being easily recognised. 

It might be worth mentioning the importance of e-noses in wine analysis, as it shares common aspects with perfume analysis quality analysis by oenologists and panelhsts, degradation assays, adulteration detection, the common presence of relatively high percentages of ethanol, etc. However, this topic falls outside the scope of this book, which deals with cosmetic products. 

Glyceryl acetate, which is an artificial ester commonly used in the adulteration of bergamot oil, is detected fairly easily on account of its high solubility in dilute alcohol. The test is carried out as follows Ten c.c. of bergamot oil and 20 c.c. of 5 per cent, alcohol are well shaken in separating funnel, and after the solutions have separated and become clear the watery solution is run off and filtered. Ten c.c. of the filtrate are exactly neutralised with deci-normal alkali, and then 5 c.c. of seminormal alkali run in, and the whole saponified under a reflux condenser for one hour. In the case of pure bergamot oil 0 1 or at most 0 2 c.c. of semi-normal alkali will have been used up by the saponification, whilst each 1 per cent, of glyceryl triacetate present in the oil will be represented by practically 0 5 c.c. of semi-normal alkali. 

Most of the applications of HPLC for protein analysis deal with the storage proteins in cereals (wheat, corn, rice, oat, barley) and beans (pea, soybeans). HPLC has proved useful for cultivar identihcation, protein separation, and characterization to detect adulterations (illegal addition of common wheat flour to durum wheat flour) [107]. Recently Losso et al. [146] have reported a rapid method for rice prolamin separation by perfusion chromatography on a RP POROS RH/2 column (UV detection at 230nm), sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis (PAGE), and molecular size determination by MALDl-MS. DuPont et al. [147] used a combination of RP-HPLC and SDS-PAGE to determine the composition of wheat flour proteins previously fractionated by sequential extraction. 

The trade adulterations of calomel are chalk, sulphate of baryta, carbonate of lead, common salt, sal ammoniac, and sometimes a little corrosive sublimate. 1 For the detection of all impurities, the Edinburgh college dirocte that heat, sulphuric ether, and solution of caustic potoasa should be employed. Calomel, ff pure, is entirely volatilized by heat, all fixed impurities will therefore be found in the residue, whilst the sublimate may contain, besides calomel, the mercuric chloride and sal ammoniac. These impurities being soluble in water,... 

PK McCarthy, BF Scanlon, IC Lumley, M Griffin. Detection and quantification of adulteration of durum wheat flour by flour from common wheat using reverse phase HPLC. J Sci Food Agric 50 211-226, 1990. 

Individual anthocyanin composition is distinctive for any given plant, so anthocyanin analysis is very useful in distinguishing between species. Chemotaxonomic differentiation is commonly based on qualitative differences (163), furthermore within one cultivar (e.g., grapes) even varieties can be discriminated by quantitative differences (164). The anthocyanic profiles of 11 different grape varieties obtained with RP-HPLC are shown in Fig. 15 (165). The characteristic differences in anthocyanin patterns have also been successfully applied to the detection of adulterations in products of cranberries (166), black currants (166), blackberries (167), and grapes (168). 

The methods used to detect adulteration of juices have been reviewed by a number of authors and two examples are given here (Fry el al., 1995 Hammond, 1996). With the changing methods of unscrupulous suppliers it is now common to use a battery of tests to ensure that a product is authentic. Although this is costly, it is the only way to ensure the authenticity of a product and protect company reputations. The array of tests will often include a number of the procedures described above, such as sugar and acid profiles, along with other methods such as stable isotopic and fingerprinting procedures. 

ELISA s (54, 55) are one of the most commonly used immunoassays in the food industry for detection of a wide variety of substances including contaminants, toxins, adulterants, herbicides and carcinogens. They use an enzyme as a label and visualization is achieved via conversion of the substrate to a colored product. There are different types of ELISA s i.e., competitive (Fig. 7), non-competitive (Fig. 8), sandwich (Fig. 9) and homogeneous enzyme immunoassay (48). 

Urine is currently the most common specimen for detection of drugs of abuse. Hovrever, the window of detectability in urine is generally limited to a few days following drug use. In addition, the collection of urine may require some invasion of privacy and loss of dignity, and urine specimens are subject to adulteration or manipulation to evade detection. For these reasons, alternate biological specimens that may avoid some of these limitations have been investigated/ ... 

It was commonly thought by those in authority that if mithridatum or theriac did not produce the desired cure, this was due to incorrect preparation (perhaps with adulterated or poor-quality materials) or to incorrect storage after use. As the only cause for therapeutic failure therefore lay with the pharmacist who compounded the mixture, the remedy lay in careful scrutiny of manufacture, which should be in public. Any misdemeanor should then be detected and immediately punished. 

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