A reverse-phase liquid chromatography analysis is used to access the quantity of theobromine, (+)-catechin, caffeine, and (-)-epicatechin in Standard Reference Material 2384 Baking Chocolate, cocoa, cocoa beans, and cocoa butter using water or a portion of the mobile phase as the extract. The procedure requires minimal sample preparation. Theobromine, (+)-catechin, caffeine, and (-)-epicatechin are detected by UV absorption at 273 nm after separation using a 0.3% acetic acid-methanol gradient (volume fractions) and quantified using external standards. The limit of detection for theobromine, (+)-catechin, caffeine, and (-)-epicatechin averages 0.08, 0.06, 0.06, and 0.06 microg/mL, respectively. The method when applied to Standard Reference Material 2384 Baking Chocolate; baking chocolate reference material yields results that compare to two different, separate procedures. Theobromine ranges from 26000 mg/kg in cocoa to 140 mg/kg in cocoa butter; (+)-catechin from 1800 mg/kg in cocoa to below detection limits of < 32 mg/kg in cocoa butter; caffeine from 2400 mg/kg in cocoa to 400 mg/kg in cocoa butter, and (-)-epicatechin from 3200 mg/kg in cocoa to BDL, < 27 mg/kg, in cocoa butter. The mean recoveries from cocoa are 102.4 +/- 0.6% for theobromine, 100.0 +/- 0.6 for (+)-catechin, 96.2 +/- 2.1 for caffeine, and 106.2 +/- 1.7 for (-)-epicatechin.

BACKGROUND: A number of individual high-performance liquid chromatography (HPLC) procedures exist for the analysis of maltol, theobromine, ethyl maltol, catechin, vanillic acid, caffeine, vanillin, epicatechin, and ethyl vanillin. A single procedure utilizing simple sample preparation and less sophisticated equipment would be advantageous for the analysis of different sample types containing these compounds.RESULTS: An HPLC procedure has been developed using water as the extract for consumer products and artificial flavors. A methanol-water gradient was used to elute the compounds of interest using a reverse-phase column. Absorbance detection using a wavelength of 273 nm was used to monitor the eluent. Recoveries for these compounds ranged from 88% to 104%.CONCLUSIONS: Results obtained for theobromine, catechin, caffeine, and epicatechin in Standard Reference Material 2380 Baking Chocolate compare well with those found in its certificate of analysis verifying that the procedure is valid. Vanillic acid and ethyl vanillic acid were found as oxidation products of vanillin and ethyl vanillin in both standards and some consumer products. (c) 2008 Society of Chemical Industry.

An improved high performance liquid chromatography (HPLC) analysis of glycyrrhizic acid (GA) in licorice and tobacco to which licorice was applied was developed. An acetate buffer was used in the mobile phase, which resulted in more constant retention times for GA. Nine extractants were found to remove GA from licorice, but only six were capable of removing GA from both licorice and tobacco. Precision was less than 4% relative standard deviation for licorice and tobacco and percent recoveries were at least 92. Aqueous solutions of 1,4-dioxane, ethanol, tetrahyrofuran, 2-butoxyethanol, 2-methoxyethanol, and 1,3-dioxolane can be used to extract GA from both licorice and tobacco. Glycyrrhetinic acid and compounds found in tobacco do not interfere with the analysis.

A high performance liquid chromatography (HPLC) method was developed for the quantification of the phenolic compounds hydroquinone, catechol, phenol, 3-methylcatechol, scopoletin, m+p-cresol and o-cresol in indoor air samples. Samples are collected on an 0.8 mum pore size mixed cellulose ester membrane (MCEM) followed by a silica gel Sep-Pak (SiOHSP). The MCEM is extracted and the SiOHSP is eluted with 1 % acetic acid (HAc). The phenolic compounds were analyzed on a reverse-phase column with fluorescence detection at selected excitation and emission wavelengths specific to the compounds of interest. A mobile phase gradient of 1 % HAc and 99 % acetonitrile (ACN) + 1 % HAc is used. The method is reproducible with percent relative standard deviations (% RSD) ranging from 2.0 to 9.2 for the seven phenolic compounds. Percent recoveries are acceptable (88-98) with the exception of scopoletin (52) and p-cresol (52). A comparison of tobacco versus wood smoke show that amounts of these seven phenolic compounds vary widely with their source. A relatively short sampling time (1-4 hours) is required and the procedure is capable of detecting < 0.3 mug m-3 for all compounds with the exception of 3-methylcatechol with a detection limit of < 4.0 mug m-3.

A new, all aqueous high-performance liquid chromatography (HPLC) procedure for the determination of 5-hydroxymethylfurfural (HMF) in honey and other sugar-containing materials was developed without harmful chemicals. The method involved dilution of the sample in water and the analysis of the diluent using an HPLC system equipped with an absorbance detector and a 30-mm sulfonated poly(styrene-divinylbenzene) cation exchange column. Water was used as the mobile phase at a high flow rate of 2.00 mL/min. Using this high flow rate in conjunction with a column heater set at 55 degrees C, HMF eluted in less than 4 min. Overall precision was less than 1% relative standard deviation, recovery of HMF from spiked samples was approximately 99%, and there were no interferences from similar compounds such as 2-furfural and 5-methylftirfural. Several sugar containing materials were analyzed by this method where the results compared well with the classic Winkler spectrophotometric procedure, but not as well with a commonly used reverse-phase HPLC technique. In addition, several consumer products were also analyzed for their HMF content.

The particle-gas equilibria of ammonia and nicotine in mainstream cigarette smoke have been studied by diffusion denuder collection. The surface deposition rate of nicotine is observed to decrease as the smoke traverses the denuder, and this effect is attributed to a changing particle nicotine vapor pressure driven by the measured rapid loss of volatile ammonia from the particles, an interpretation that differs from that of prior studies. The rapid ammonia deposition is observed to be complete at a length-to-flow rate ratio of 28 s/cm(2) for an American blended cigarette, and similar to 38% of the total ammonia analyzed in the collected smoke appears to be nonvolatile in the aerosol, possibly bound in the particles by reaction with acids. Fitting of a theoretical model that predicts the rapid ammonia loss and changing nicotine vapor pressure to the measurements predicts that the nicotine vapor pressure over the particles in fresh smoke is about 6% of the pure component nicotine value, and the ammonia vapor pressure over the smoke particulate is considerably less than that predicted by its aqueous Henry's law coefficient. Dilution of mainstream smoke enhanced the fractional deposition of both ammonia and nicotine in the denuder tubes and provided a means to estimate the nonvolatile ammonia fraction, which varied considerably in cigarettes made with different tobacco types. Among the different tobacco type cigarettes, smoke ammonia concentration, "smoke pH," and smoke nicotine-to-particulate ratio varied with ammonia and nicotine deposition from diluted smoke when extreme values for an all burley tobacco cigarette were included in the analysis, but no trends were apparent when only the more typical range of the other cigarettes was considered.

A new-technology cigarette has been developed. While the new cigarette burns some tobacco, it does not use tobacco as the fuel to sustain combustion and provide heat to the cigarette. Rather, the new cigarette primarily heats tobacco thereby reducing products of smoke formation mechanisms such as tobacco combustion, tobacco pyrolysis and pyrosynthesis. The mainstream smoke composition From a cigarette based on the new design (TOB-HT) has been characterized in comparative chemical testing with two reference cigarettes using the FTC puffing regimen. Thermal properties, UV absorption characteristics. elemental composition and materials balance studies all suggest a simplified smoke aerosol. Twenty-five smoke constituents ("target compounds") identified by the scientific community as compounds that may contribute to the diseases statistically associated with smoking have also been measured. Mainstream smoke concentrations of most target compounds are significantly lower with the TOB-HT cigarette when compared with reference cigarettes in the ultra-light "tar" and light "tar" categories. Taken together, chemical analysis results suggest simplified TOB-HT smoke chemistry with marked reductions in specific chemicals reported to be biologically active. (C) 1998 Elsevier Science Ltd. All rights reserved.

A high-performance liquid chromatographic method is described for the quantitation of (+)-alpha-tocopherol in the particulate phase of environmental tobacco smoke (ETS) collected on a 1-micron pore size Fluoropore membrane. A methanol (MeOH) extract of the membrane, which can be used for four other ETS procedures, is analyzed for (+)-alpha-tocopherol on a reversed-phase column with fluorescence detection at selective wavelengths of 280 nm excitation and 330 nm emission. A mobile phase of MeOH and water is used. The method is reproducible with a relative standard deviation (%) of about 12. Recovery is 88%, and the procedure is capable of detecting greater than 0.04 microgram/m3 (+)-alpha-tocopherol in ETS. A comparison of the ETS from five commercially available cigarettes shows similar (+)-alpha-tocopherol concentrations. A cigarette that primarily heats tobacco yields about 6% of that amount of (+)-alpha-tocopherol found in ETS from tobacco-burning cigarettes. (+)-alpha-Tocopherol can be used as a marker for ETS respirable suspended particles (RSP) because it is found at a consistent amount in ETS RSP of 0.29%. However, sufficient amounts of RSP would have to be generated in order to detect (+)-alpha-tocopherol.

A new-technology cigarette has been developed. While the new cigarette burns some tobacco, it does not use tobacco as the fuel to sustain combustion and provide heat to the cigarette. Rather, the new cigarette primarily heats tobacco thereby reducing products of smoke formation mechanisms such as tobacco combustion, tobacco pyrolysis and pyrosynthesis. The mainstream smoke composition from a cigarette based on the new design (TOB-HT) has been characterized in comparative chemical testing with two reference cigarettes using the FTC puffing regimen. Thermal properties, UV absorption characteristics, elemental composition and materials balance studies all suggest a simplified smoke aerosol. Twenty-five smoke constituents ("target compounds") identified by the scientific community as compounds that may contribute to the diseases statistically associated with smoking have also been measured. Mainstream smoke concentrations of most target compounds are significantly lower with the TOB-HT cigarette when compared with reference cigarettes in the ultra-light "tar" and light "tar" categories. Taken together, chemical analysis results suggest simplified TOB-HT smoke chemistry with marked reductions in specific chemicals reported to be biologically active.

The environmental tobacco smoke (ETS) yield of selected analytes was determined for the 50 top-selling U.S. cigarette brand styles (1991) and the University of Kentucky Research cigarette, K1R4F. ETS was generated by smokers in an environmental test chamber. Analytes determined included real-time measurements of nicotine, 3-ethenylpyridine, respirable suspended particles (RSP), carbon monoxide, and total hydrocarbons by flame ionization detector response (FID). Real-time RSP values were determined independently by a piezoelectric balance and real-time aerosol monitor (RAM). Additional analytes determined on a time-integrated basis included: nicotine, 3-ethenylpyridine, myosmine, RSP, ultraviolet particulate matter (VUPM), fluorescent particulate matter (FPM), solanesol, scopoletin, formaldehyde, acetaldehyde, acetone, catechol, ammonia, 34 volatile organic compounds (VOCs), and total VOCs (estimated by GC/mass spectrometric response). In general, lowering mainstream tar resulted in lower ETS emissions. The current study showed that ETS-RSP and nicotine were not predictive of each other. In fact, this ETS market brand style comparison showed a poor relationship between ETS nicotine and ETS-RSP. ETS analyte yields are summarized by mainstream tar categories, and overall sales-weighted average yields are calculated. Sales-weighted average ETS-RSP yields for full flavor (FF), full flavor low tar (FFLT), and ultra low tar (ULT) were 14.86, 12.30, and 10.51 mg/cig, respectively. The average RSP yield for all cigarettes evaluated was 13.67 mg/cig. These results, based on 65.3% of the U.S. cigarette market, should enable better estimations of the contribution of ETS to indoor air.

A high-performance liquid chromatographic method is described that quantitates the carbonyl compounds formaldehyde, acetaldehyde, and acetone from ambient air as their 2,4-dinitrophenylhydrazine (DNPH) derivatives. Acrolein is detected and, although its precision is acceptable, it exhibits poor recovery and stability due to dimer formation. After evaluating several DNPH-coated devices for sample collection, a commercially available device is chosen because it has a high capacity and minimal contamination of these compounds. After sampling 60 L of air, the device is eluted with acetonitrile, and an aliquot of the eluant is analyzed using a reversed-phase column, ultraviolet detection, and a mobile phase gradient with tetrahydrofuran as a modifier. Acrolein and acetone are fully resolved by this chromatography. For formaldehyde, acetaldehyde, and acetone, the precision is less than 2.5% relative standard deviation, and the recoveries are greater than 82%. The responses for all analytes are linear over a 20-fold concentration range. The minimum detectable quantity for each compound is less than 3 μg/m3 for a 60-L sample. The analyses of various samples show that the amounts of these carbonyl compounds vary widely.

A method is described for the collection and quantitation of formaldehyde, acetaldehyde, and acetone in sidestream cigarette smoke. Using the "fishtail" chimney procedure (1), sidestream smoke is drawn by vacuum through the chimney, a Cambridge filter pad (Performance Systematics Inc.; Caledonia, MI), and into an impinger containing a solution of 2,4-dinitrophenylhydrazine (DNPH), whose solubility in acetonitrile was increased by using diglyme as a constituent of the collection derivatization solution. The chimney is rinsed with DNPH solution to remove "formaldehyde", and the rinse is added to the impinger solution. This combined wash and impinger solution is used to extract the Cambridge pad. An aliquot of the extract is analyzed by high-performance liquid chromatography using a reversed-phase column, ultraviolet detection, and a mobile phase gradient with tetrahydrofuran as a modifier. Acrolein is detected but gives poor precision and recovery because of dimer formation. For formaldehyde, acetaldehyde, and acetone, both the precision (7.30, 2.49, 2.88% relative standard deviation, respectively) and recovery (90.0, 95.2, 102.8%, respectively) are acceptable. The response for formaldehyde, acetaldehyde, and acetone is linear and a function of the number of cigarettes smoked. The minimum detectable quantity for the analytes ranges from 5 to 16 micrograms per cigarette.

An active sampling method based on a solid-phase collection medium was used to determine ammonia concentrations in indoor air. A weak cation exchange cartridge was used to collect ammonia, which was then eluted from the cartridge with 0.02 M HCl and determined by cation exchange chromatography (CEC) with conductivity detection. The method was applied to quantify the ammonia in environmental tobacco smoke (ETS) and is compared to an impinger collection technique. The method was reproducible with a relative standard deviation of 2.0%. Percent recovery is about 98%. Analyses of samples collected in a variety of situations showed that ammonia concentrations vary. With a relatively short sampling time of 0.5 to 1 h, this procedure was capable of detecting ammonia above 5-mu-g m-3 under the sampling conditions.

A high-performance liquid chromatography (HPLC) method was developed for the quantification of the polynuclear aromatic hydrocarbons (PAHs) chrysene, benzo[b]fluoranthene(B[b]F), benzo[a]pyrene (B[a]P) and benzo[ghi]perylene (B[ghi]P) in the particulate matter of indoor air samples. Samples were collected on 1-mu-m pore size Fluoropore membrane filters and extracted with acetonitrile (ACN). The PAHs were analyzed on a polymeric octadecysilane, silica-based column (Vydac 201TP54) with fluorescence detection at selected excitation and emission wavelengths specific to the compounds of interest. A mobile phase gradient of water and ACN was used. The method is reproducible with percent relative standard deviations (%RSD) ranging from 5.0 to 9.6 for the five PAHs. Percent recoveries were ca. 100%. Analyses of various samples show that amounts of these five PAHs vary widely in air. A relatively short sampling time (five hours) is required and the procedure is capable of detecting < 1 ng m-3.

A quantitative method for the determination of benz[a]anthracene (B[a]A) and benzo[a]pyrene (B[a]P) in mainstream and sidestream cigarette smoke by high performance liquid chromatography (HPLC) has been developed. Mainstream and sidestream particulate matter is collected on Cambridge filter pads. The polycyclic aromatic hydrocarbons (PAH) are extracted with cyclohexane and subjected to normal-phase chromatography to isolate target fractions which are concentrated and then diluted with acetonitrile or acetonitrile/water prior to reverse-phase analytical chromatography.The Kentucky Reference cigarette 1R4F and a cigarette which heats but does not burn tobacco (New Cigarette) developed at R. J. Reynolds Tobacco Company were analyzed and compared with respect to B[a]P and B[a]A in both mainstream and sidestream smoke.

A high performance liquid chromatography method is described which quantifies hydroquinone, catechol, phenol and m+p‐creaol in indoor air samples. Results from collection devices, extraction solvents and collection media show the pitfalls that can be encountered when sampling indoor air. Air samples are collected by means of a mixed cellulose‐ester membrane which has an affinity for dihydroxy phenols followed by an impinger which traps the more volatile monohydroxy phenols. Sample extracts are subjected to reverse‐phase, gradient liquid chromatography with fluorescence detection. Some compounds are detected at the submicrogram per cubic meter concentration.

A high-performance liquid chromatographic (HPLC) method is developed that simultaneously quantifies the dihydroxy compounds hydroquinone, resorcinol, and catechol and the monohydroxy compounds phenol, m + p-cresol and o-cresol in cigarette smoke. Particulate matter samples collected on Cambridge pads and in impingers by conventional trapping techniques are simply (no derivatization required) subjected to reversed-phase gradient liquid chromatography. Samples of both mainstream and sidestream smoke can be analyzed. Selective fluorescence detection is used to monitor the mobile phase effluent, by which these phenolic compounds are detected in the nanogram range. The detector response is linear, overall precision is good, and recoveries are greater than 95 percent. The total run time, excluding extraction, is one hour. The procedure has been applied to tobacco products whose smoke contains varying amounts of these phenols. Kentucky Reference Cigarette 1R4F was found to contain substantially more of these compounds than a new cigarette that heats but does not burn tobacco (New Cigarette). The method is compared with other procedures used to determine phenolics in cigarette smoke.

A procedure for the isolation and determination of benzo[a]pyrene in the total particulate matter of cigarette smoke is described. Two high-pressure liquid chromatographic (HPLC) techniques are employed: a normal-phase, mu Bondapak-NH2, amino column is used for isolation of the benzo[a]pyrene fraction and a reversed-phase, Vydac 201TP54, polymeric octadecyl silane column is used for quantitation. Fluorescence detection is used in both modes of chromatography. The wavelengths of excitation and emission are evaluated for analytical detection. Extraction media and various isolation techniques are compared for their extraction efficiency and isolation from interferences, respectively. The procedure is efficient, reproducible, sensitive (3 pg), and gives results that compare favorably with other techniques reported in the literature for the B[a]P content of reference cigarettes, 1R1 and 1R4F.