Simplex optimization of headspace factors for headspace gas chromatography determination of residual solvents in pharmaceutical products.

The purpose of the present work was to find optimum conditions of headspace gas chromatography (HS-GC) determination of residual solvents which usually appear in pharmaceutical products. Two groups of solvents were taken into account in the present examination. Group I consisted of isopropanol, n-propanol, isobutanol, n-butanol and 1,4-dioxane and group II included cyclohexane, n-hexane and n-heptane. The members of the groups were selected in previous investigations in which experimental design and chemometric methods were applied. Four factors were taken into consideration in optimization which describe HS conditions: sample volume, equilibration time, equilibrium temperature and NaCl concentration in a sample. The relative GC peak area served as an optimization criterion which was considered separately for each analyte. Sequential variable size simplex optimization strategy was used and the progress of optimization was traced and visualized in various ways simultaneously. The optimum HS conditions appeared different for the groups of solvents tested, which proves that influence of experimental conditions (factors) depends on analyte properties. The optimization resulted in significant signal increase (from seven to fifteen times).

Grouping of residual solvents present in pharmaceuticals using experimental planning and chemometric methods.

The main effects of six experimental factors on the efficiency of HS (headspace) extraction in headspace gas chromatography--flame ionization detector (HS-GC-FID) determination of twenty organic solvents routinely used in production of pharmaceuticals were obtained on the basis of the results of experiments carried out according to the Plackett-Burman factorial design. The effects were used as a basis for grouping the solvents into five groups, the solvents belonging to a group responded similarly to changes of HS conditions. To this end, visualization approaches were used as well as chemometric methods: cluster analysis (CA) and principal component analysis (PCA). Moreover, the most important HS experimental factors were selected for further optimization of the HS-GC determination procedure.

[The influence of periodontal diseases on the concentration of selected metals in saliva]. / Wplyw chorób przyzebia na stezenie wybranych metali w slinie.

Analysis of elements (mainly metals) in biological materials provides a challenge for analytics. It results from complex matrix of this kind of samples and strict requirements for purity at all stages of the analytical process. Over the years many effective methods for determination of metals in body fluids have been developed, which link with searching for the association between elemental composition of human body and various diseases. The aim of the investigation was to study the usefulness of available methodology to determination of selected metals in saliva and blood of patients with periodontitis and healthy controls by two techniques" ICP-MS and ICP-OES. Next statistical analysis of the data statistical was carried out. The influence of periodontal disease upon the concentrations of selected metals (Ca, Cd, Co, Cr, Cu, Fe, Mg, Mn, Pb and Zn) in saliva was examined, as well the attempt to classify samples of patients with periodontitis and healthy individuals correctly was made. Additionally mutual relations between analytes in examined materials were determined by computing the Pearson's correlation coefficient and principal component analysis (PCA).

[Physiological metals in the serum, hair and nails of patients with head and neck cancer]. / Metale fizjologiczne w surowicy, we wlosach i paznokciach pacjentów z nowotworami w obrebie glowy i szyi.

Cigarette smoking and excessive alcohol drinking result in the rise of numbers of patients suffering from the head and neck cancer. Addiction to any of these stimulants carry a risk of developing a cancerogenesis process. Using them simultaniously lead not to a summary of each of those risks but multiplies them. Scientific research also indicates the important difference in the incidence of cancer in people who have never smoked cigarettes or drunk alcohol in comparison to those, whose exposure to these stimulatns was longterm - in such case, the former group had a lower percentage of developing the disease. Human body burdened with the ongoing cancer shows disturbances on various levels of the system. One of such disturbances is change of the concetration levels of physiological metals, such as calcium, magnesium, iron, copper, zinc or mangenese. They play key roles in maintaing the hormonal and ionic stability, they act as cofactors in many enzymes in metabolic processes. Diagnostic research of any deviations in levels of those essential elements enables a full estimation of a patient condition. The aim of this study was physiological metal levels evaluation in different kinds of biological material in patients with tumors of larynx, salivary glands and oral cavity and tongue. Hair and nail samples were used as examples of alternative material, beside the serum samples, which is a standard material and often used. Subjects were patients of Otolaryngology and Laryngological Oncology Clinic of Poznan University of Medical Sciences (Samodzielny Publiczny Szpital Kliniczny nr 2 im. Heliodora Swiecickiego Uniwersytetu Medycznego im. Karola Marcinkowskiego w Poznaniu) and The Head and Neck Surgery Ward of The Greater Poland Cancer Centre in Poznan. Subjects were 41 men and 18 women with tumors of larynx, salivary glands and oral cavity and tongue. The control group consisted of patients from the Otolaryngology and Laryngological Oncology Clinic of Poznan University of Medical Sciences (Samodzielny Publiczny Szpital Kliniczny nr 2 im. Heliodora Swiecickiego Uniwersytetu Medycznego im. Karola Marcinkowskiego w Poznaniu), The Head and Neck Surgery Ward of The Greater Poland Cancer Centre in Poznan and patients of Department of Endocrinology, Metabolism and Internal Medicine of Poznan University of Medical Sciences (Samodzielny Publiczny Szpital Kliniczny nr 2 im. Heliodora Swiecickiego Uniwersytetu Medycznego im. Karola Marcinkowskiego w Poznaniu) and Department of Conservative Dentistry and Periodontology Poznan University of Medical Sciences. They gave answers to the questionnaire concerning smoking habits, alcohol consumption and dietary habits, Then the samples of their serum, hair and nails were collected. After careful preparations the biological material has underwent the process of digestion, and then calcium, magnesium, iron, copper, zinc, mangenese were determined quantitatively using the method of ICP-MS. Profile of the patients who took part in the research displayed a strong correlation between tobacco smoking with alcohol drinking and appearance of larynx, salivary gland and oral cavity and tongue cancer as well as between exclusively tobacco smoking and appearance of these types of cancer. There is a higher incidence of larynx, salivary gland and oral cavity and tongue cancer when there is a deficiency of grain products or fibre in everyday diet. A higher level of calcium, magnesium, iron and manganese was found in patients' hair and nails who suffered from salivary gland cancer. According to applied Chemometric Analysis of Principal Component 1 - concentrations of iron, copper and manganese with magnesium and zinc in patients' nail samples showed strong correlation between measured variables. In patiens' hair samples measured correlation between variables was decreased - concentrations of calcium and magnesium as well as of iron and manganese were highlighted as two groups of variables which showed some correlation in this type of biological material. Further research is required to indicate which of alternative biological materials - hair or nail samples - in relation to serum, would provide a better evaluation of physiological metal levels.

Visualisation of Amphetamine Contamination in Fingerprints Using TOF-SIMS Technique.

Time-of-flight secondary ion mass spectrometry (TOF-SIMS) was applied to detect traces of amphetamine on fingerprints. In the present study, three different lift tapes and latent powder fingerprints were tested. The obtained results show that it is possible to identify traces of a drug as well as its distribution over the tested fingerprint after its transfer from the primary base onto an adhesive lifter (secondary base). Moreover, images obtained by the TOF-SIMS technique enable the observation of very small areas of the analysed fingerprint as well as the identification of micro-objects (residues of a contaminant) that were left on the fingerprint. The use of the black latent fingerprint powder did not interfere with the TOF-SIMS analysis, which makes it possible to effectively use this technique to study the traces of substances on the revealed fingerprints.

Analytical methods for residual solvents determination in pharmaceutical products.

Residual solvents (RS) are not desirable substances in the final pharmaceutical product and their acceptable limits have been published in pharmacopoeias and ICH guidelines. The intension of this paper was to review and discuss some of the current analytical procedures including gas chromatographic (GC) and other alternative techniques which are used for residual solvents determination. GC methods have been developed to monitor this kind of impurities routinely. The most popular techniques of sample introduction into the gas chromatograph include direct injection, static or dynamic headspace, solid-phase microextraction and single drop microextraction. Different separation techniques like two dimensional chromatography or multicapillary chromatography were compared with classical separation mode with use of single capillary column. Also alternative methodologies for residual solvents testing were discussed in this review. In conclusions, gas chromatography-based procedures were described as the most appropriate because of the lowest detection limits, ease of sample preparation and specificity.

Organic solvents in the pharmaceutical industry.

Organic solvents are commonly used in the pharmaceutical industry as reaction media, in separation and purification of synthesis products and also for cleaning of equipment. This paper presents some aspects of organic solvents utilization in an active pharmaceutical ingredient and a drug product manufacturing process. As residual solvents are not desirable substances in a final product, different methods for their removal may be used, provided they fulfill safety criteria. After the drying process, analyses need to be performed to check if amounts of solvents used at any step of the production do not exceed acceptable limits (taken from ICH Guideline or from pharmacopoeias). Also new solvents like supercritical fluids or ionic liquids are developed to replace "traditional" organic solvents in the pharmaceutical production processes.

Fingerprinting of 3, 4-methylenedioxymethamphetamine markers by desorption/ionization on porous silicon.

Desorption/ionization on porous silicon (DIOS) is a method which extends the application range of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. This technique eliminates matrix background in the low mass range; DIOS is especially advantageous in research on small organic molecules and their metabolites in biological samples. DIOS mass spectrometry was applied for 3, 4-methylenedioxymethamphetamine, (MDMA, Ecstasy) impurities identification. Trace components profiling enables the identification of by-products characteristics for the synthesis route of MDMA. Ecstasy, a synthetic psychoactive drug, is highly popular among young people, and often used as a recreational drug, most commonly used during disco parties. MDMA enhances feeling of euphoria by increasing the level of neurotransmitters such as serotonin, dopamine and norepinephrine, and causes acute behavioral and psychological effects. MDMA is almost exclusively produced illegally, primarily in Western Europe. The new method for MDMA impurities profiling has been developed to trace the origin of MDMA pills. For comparison and classification of the impurity profiles, the principal components analysis was used.

Fentanyl and its analogues in clinical and forensic toxicology.

Fentanyl and its analogues are commonly named synthetic opiates. Some compounds from fentanyl group (e.g. fentanyl, alfentanil, sufentanil, remifentanil) are used as anaesthetic and analgesic of high potency and short duration of action. Effects of acting fentanyls are indistinguishable from those produced by nasal inhalation of street heroin. In view of this, fentanyls are very "attractive" for the narcotic market. In least years an increase in number of reports about illegal production and non-medical use of fentanyl and its analogues have appeared. Numerous fentanyl analogues are sold under one name synthetic heroine or China white. Fentanyl and its analogues also can be used as gas warfare agents. One of fentanyl-related compound was used during action of easing hostages from Dubrovka theatre. Because of respiratory depression, which was caused by used compound, died over 100 hostages. Because of high potency fentanyl-related compounds are used in very low doses. So fentanyls appear in biological material in very low concentrations, not higher than several nanograms per millilitre or per gram. The drugs in these concentrations cannot be detected by means of routinely used screening procedures. Therefore direct methods for determination of this group of compounds are needed. Screening method for determination of fentanyl and its analogues was elaborated and validated. Liquid chromatography-mass spectrometry (LC/MS) technique was applied. The method is characterised by the limit of quantification (LOQ) and the limit of detection (LOD) ranged from 0.6 to 2 ng/ml and from 0.2 to 0.6 ng/ml, respectively for four above-mentioned compounds. The method was used for determination of fentanyl in three forensic cases. The blood, bile and blood from lung samples were taken during autopsy of persons who died shortly after surgical procedure in which fentanyl was used as an adjunct to general anaesthesia.

Optimization of solid-phase microextraction conditions for gas chromatographic determination of ethanol and other volatile compounds in blood.

A procedure for the determination of acetaldehyde, acetone, methanol, ethanol, 1-propanol and 2-propanol in blood was developed. Separation of analytes was carried out on DB-wax capillary column (l = 30 m, I.D. = 0.32 mm, dF = 0.5 microm) at 40 degrees C, hydrogen was used as a carrier gas (at 30 kPa) and FID as a detector. Quantification was performed with the use of 2-butanol as an internal standard. Headspace solid-phase microextraction was applied as the sample preparation technique. The usefulness of most commercially available fiber coatings was checked and 65 microm Carbowax/DVB proved most effective. Microextraction was carried out from the headspace at 60 degrees C for 10 min. The sample was stirred at 750 rpm. In order to improve the extraction efficiency of analytes, salting-out agents were also applied. Potassium carbonate turned out to be the most efficient. A 1.0-g amount of this salt and 0.1 ml of I.S. were added to 0.5 ml of sample. Validation of the worked-out method was performed. For each analyte, the limits of detection and quantification, linearity, working range, accuracy and precision were determined or tested.

Concentration of ethanol and other volatile compounds in the blood of acutely poisoned alcoholics.

The presence of volatile compounds, such as acetone, acetaldehyde, methanol, ethanol, isopropanol, and n-propanol, in the blood of 169 acutely poisoned alcoholics was determined. The clinical diagnosis of addiction was made on the basis of a patient interview as well as physical, psychological, and psychiatric examination. At the time of the patients' admission to the clinic, the mean concentration of ethanol in blood was 3.14 +/- 1.10 g/l and its elimination rate in the studied group was 0.27 +/- 0.08 g/kg/hr, an elimination rate significantly higher (P <.001) than that of social drinkers, which averages to 0.014 +/- 0.04 g/kg/h. The presence of other volatile compounds in the blood of alcohol-addicted patients is common. The calculated elimination rate constant of methanol was about 0.2 h(-1). This rate seems to indicate that, in heavy drinkers, the elimination of methanol may be relatively fast even if the ethanol concentration is above 1 g/l. The elimination of other volatile compounds can be accelerated by large doses of ethanol, although it is not correlated with actual blood ethanol level. Moreover, in most of the blood samples with a methanol concentration below 10 mg/l, the measured concentration of acetone was below 7 mg/l and that of isopropanol was below 2 mg/l.

HPLC/DAD Screening Method for Selected Psychotropic Drugs in Blood.

The influence of experimental conditions on gradient high-performance liquid chromatography/diode array detector separation and identification of 13 psychotropic drugs belonging to two groups--phenothiazines and tricyclic antidepressants--was examined. The main interaction effects of three experimental factors were determined according to a 2 3 factorial design, and the optimum conditions of analysis were searched for. The degree to which the chromatographic peaks overlap is taken into account in a proposed criterion for separation quality. The screening analysis proposed was tested on whole blood samples spiked with mixtures of the examined drugs. The method was characterized by such validation parameters as relative retention times, absorbance ratios at two wavelengths, detection limits, linearity ranges, and extraction recoveries. The method proved to be a suitable tool for the identification of psychotropic drugs tested for forensic purposes.