Allergenic Substances Research Articles

Determination of home-made wine selected parameters and study of honey addition impact on pro-healthy components content

The chemical characteristic of home-made wine, based on the vinification process of Maréchal Foch grapes with minimal intervention, was discussed. The addition of honey in the vinification process has been studied to improve the parameters of the pro-health properties of wine. Assays of antioxidant capacity, pH, colour intensity, total acidity, histamine, tyramine, tryptamine and phenylethylamine contents were carried out during the fermentation, maturation and storage processes. Moreover, the discussed above and selected oenological and quality parameters (organic acids, metals, total and free sulphur dioxide, alcohol content) of obtained wines were compared with commercial wines. Obtained results of allergenic compounds (SO2 and histamine) showed a significantly lower level for home-made wines. The presence of honey during the fermentation process significantly improved the antioxidant parameters, titratable acidity, and influenced the final product colour intensity and colour brilliance. The obtained data show that home-produced wine seems to be a valuable alternative to traditional commercial production due to the lack of chemical additives and potentially allergenic substances in the presence of compounds that enhance human health. Moreover, minimal intervention during fermentation, no filtering step, no chemical additives, processing aids and clarifying substances suggest that home-made wine can be considered natural.

Standard Patch Test Results and Clinical Relevance: A Cross-Sectional Study of 10-year Retrospective Experience.

Allergic contact dermatitis (ACD) is a type IV hypersensitivity reaction, and The European Standard Series (ESS) Patch Test (PT) is widely used in determining the possible responsible allergens causing ACD. The dynamic nature of the industrial products, socioeconomic and environmental factors cause the frequency of common allergens to change over the years and among different regions. This study aimed to retrospectively evaluate the results of ESS PT of our centre in the last decade, and determine the current spectrum of allergens and their clinical relevance. The data of patients who underwent ESS PT in our clinic between January 2010 and March 2020 were included in the study. The patient files were examined retrospectively. The clinical relevance was evaluated according to the COADEX system. Statistical analysis used: SPSS for Windows version 23.0 software program. The data of 1037 patients [623 (60.1%) female, 414 (39.9%) male] were analysed. The mean age was 38.34 ± 14.55 years. The five most common allergens were nickel sulphate (23.1%), cobalt chloride (12%), potassium dichromate (9.5%), Fragrance mix II (7.3%) and balsam of Peru (5.7%). According to the COADEX coding system, current relevance was detected in 319 (49.3%) of 646 patients who had a positive reaction to any substance in the patch test. Our study showed that with increasing awareness in society, the tendency to avoid some well-known allergenic substances and consumer products causes changes in common allergens. These results prove the value of long-term surveillance of contact allergy.

Knowledge among medical students regarding the prevention of future risk of allergic contact dermatitis

BackgroundContact dermatitis is an extremely common disease in out-patient clinics. It is an inflammatory skin disease that occurs following exposure to allergic substances. Aim of the studyTo determine the extent of knowledge and information possessed by medical students in order to prevent this disease, according to the stage of their studies. Patients and methodsA cross-sectional study was conducted from December 2020 to April 2021 to assess the frequency of contact dermatitis and the extent of knowledge about the disease among medical students. The study was conducted in 315 medical students attending Al-Kindy Medical College, University of Baghdad, Baghdad, Iraq. Data was collected via an online questionnaire using Google forms. ResultsMost participants were female (62.2%). The mean age was 19.85 years (SD±1.33). Most participants did not have the disease and did not know about treatment; however, a small percentage of females showed a significant difference from males (p=0.000) as regards diagnosis of CD, knowledge about treatment, and awareness that it is a life-long disease (8.2%). DiscussionContact dermatitis is a major health concern that markedly affects many individuals. The frequency of CD in our study was 8.2% and concerned the female group alone; these subjects had knowledge about treatment of the disease and its life-long presence, while no male participants had the disease. This may be due to frequent use of house detergents, make-up lotions and ointments among females. ConclusionsThe disease was reported in a small percentage of female medical students and knowledge about CD was more common in students in the clinical-studies stage.

Immunological Analytical Techniques for Cosmetics Quality Control and Process Monitoring

Cosmetics analysis represents a rapidly expanding field of analytical chemistry as new cosmetic formulations are increasingly in demand on the market and the ingredients required for their production are constantly evolving. Each country applies strict legislation regarding substances in the final product that must be prohibited or regulated. To verify the compliance of cosmetics with current regulations, official analytical methods are available to reveal and quantitatively determine the analytes of interest. However, since ingredients, and the lists of regulated/prohibited substances, rapidly change, dedicated analytical methods must be developed ad hoc to fulfill the new requirements. Research focuses on finding innovative techniques that allow a rapid, inexpensive, and sensitive detection of the target analytes in cosmetics. Among the different methods proposed, immunological techniques are gaining interest, as they make it possible to carry out low-cost analyses on raw materials and finished products in a relatively short time. Indeed, immunoassays are based on the specific and selective antibody/antigen reaction, and they have been extensively applied for clinical diagnostic, alimentary quality control and environmental security purposes, and even for routine analysis. Since the complexity and variability of the matrices, as well as the great variety of compounds present in cosmetics, are analogous with those from food sources, immunological methods could also be applied successfully in this field. Indeed, this would provide a valid approach for the monitoring of industrial production chains even in developing countries, which are currently the greatest producers of cosmetics and the major exporters of raw materials. This review aims to highlight the immunological techniques proposed for cosmetics analysis, focusing on the detection of prohibited/regulated compounds, bacteria and toxins, and allergenic substances, and the identification of counterfeits.

Contact Dermatitis of the Vulva

The vulvar area is a common site of both irritative and allergic contact dermatitis due to the thin skin, easily traversable by irritant and allergic substances. The purpose of this review is to provide an overview of the most frequent allergens causing contact dermatitis in this particular site. A literature search was conducted via PubMed through May 2021. Relevant English language studies are included in this review. Fragrances, preservatives, botanical products, and topical medicaments were found to be the most commonly involved allergens. Contact dermatitis is a very common occurrence that should also be considered in patients with chronic vulvar or anogenital dermatitis who do not respond to appropriate treatments.

Prevalence and Risk Factors of Self-Reported Perfume Sensitivity in Saudi Arabia.

Perfumes are widely used products; however, several fragrance substances used in perfuming are well-established allergenic substances and have been attributed to various adverse health reactions. The nature and significance of perfume sensitivity reactions have not been thoroughly investigated. Therefore, this study aimed to identify the prevalence, nature, and associated risk factors of self-reported perfume sensitivity among the general population in Saudi Arabia. A nationally representative cross-sectional study was conducted among adults in Saudi Arabia in October 2020. Significant associated risk factors were explored using multivariate regression analyses. A total of 1078 participants completed the survey, with a mean age of 36.7 years (SD ± 10.36). Perfume sensitivity reactions were reported in 14.6% of participants. From among these participants, 17.8% reported moderate to severe reactions. Respiratory and skin symptoms were the most reported reactions, with total rates of 40.1% and 35.7%, respectively. History of asthma (OR = 3.2, 95%CI 1.88–4.37, p < 0.001) and the use of counterfeit perfume products (OR = 1.9, 95%CI 1.23–2.94, p < 0.003) were significantly associated with a higher risk of perfume sensitivity. Our study revealed that a considerable number of the general population in Saudi Arabia has experienced adverse health reactions due to perfume products. The enormous volume of the perfume market thus necessitates further quantitative analysis studies to determine the presence of allergenic fragrance substances in perfumes.

COVID-19 Disease, Women's Predominant Non-Heparin Vaccine-Induced Thrombotic Thrombocytopenia and Kounis Syndrome: A Passepartout Cytokine Storm Interplay.

Coronavirus disease 2019 (COVID-19) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) constitute one of the deadliest pandemics in modern history demonstrating cardiovascular, gastrointestinal, hematologic, mucocutaneous, respiratory, neurological, renal and testicular manifestations and further complications. COVID-19-induced excessive immune response accompanied with uncontrolled release of cytokines culminating in cytokine storm seem to be the common pathogenetic mechanism of these complications. The aim of this narrative review is to elucidate the relation between anaphylaxis associated with profound hypotension or hypoxemia with pro-inflammatory cytokine release. COVID-19 relation with Kounis syndrome and post-COVID-19 vaccination correlation with heparin-induced thrombocytopenia with thrombosis (HITT), especially serious cerebral venous sinus thrombosis, were also reviewed. Methods: A current literature search in PubMed, Embase and Google databases was performed to reveal the pathophysiology, prevalence, clinical manifestation, correlation and treatment of COVID-19, anaphylaxis with profuse hypotension, Kounis acute coronary syndrome and thrombotic events post vaccination. Results: The same key immunological pathophysiology mechanisms and cells seem to underlie COVID-19 cardiovascular complications and the anaphylaxis-associated Kounis syndrome. The myocardial injury in patients with COVID-19 has been attributed to coronary spasm, plaque rupture and microthrombi formation, hypoxic injury or cytokine storm disposing the same pathophysiology with the three clinical variants of Kounis syndrome. COVID-19-interrelated vaccine excipients as polysorbate, polyethelene glycol (PEG) and trometamol constitute potential allergenic substances. Conclusion: Better acknowledgement of the pathophysiological mechanisms, clinical similarities, multiorgan complications of COVID-19 or other viral infections as dengue and human immunodeficiency viruses along with the action of inflammatory cells inducing the Kounis syndrome could identify better immunological approaches for prevention, treatment of the COVID-19 pandemic as well as post-COVID-19 vaccine adverse reactions.

The Clinical Relevance of Pollen Versus Fungal Spores in Allergic Diseases

Pollen and fungal spores are associated with seasonal and perennial allergies. However, most scientific literature thus far suggests that pollen allergy is more clinically relevant than fungal allergy. Several environmental and biological factors and the difficulty in producing reliable fungal extracts account for this. Biodiversity, taxonomy, and meteorology are responsible for the types and levels of pollen and fungal spores, their fragments, and the presence of free airborne allergens. Therefore, it is difficult to accurately measure both pollen and fungal allergen exposure. In addition, understanding the enzymatic nature of fungal and some pollen allergens, the presence of allergenic and nonallergenic substances that may modulate the allergic immune response, and allergen cross-reactivity are all necessary to appropriately evaluate both sensitivity and exposure. The raw materials and manufacturing processes used to prepare pollen versus fungal extracts differ, further increasing the complexity to properly determine allergic sensitivity and degrees of exposure. The pollen extracts used for diagnosis and treatment are relatively consistent, and some have been standardized. However, obtaining clinically relevant fungal extracts is more difficult. Doing so will allow for the proper selection of such extracts to more appropriately diagnose and treat both pollen- and fungal-induced allergic diseases.

The Effects of a Fermented Rapeseed or/and Soybean Meal Additive on Antioxidant Parameters in the Blood and Tissues of Piglets.

Simple SummaryThe use of fermented products, including fermented soybean meal, and recently also fermented rapeseed meal, in the diet of pigs and other animals is becoming increasingly popular. A diet containing protein components from which anti-nutrients and allergenic substances have been eliminated by means of fermentation stimulates beneficial gastrointestinal microflora, resulting in improvement in metabolic processes and thus improved animal health.The aim of the study was to assess the effect of fermented soybean meal (FSBM) and/or rapeseed meal (FRSM) on the redox status of blood and tissues in piglets. The experiment was conducted on 150 28-day-old weaned piglets divided into five groups. Piglets in the control group received standard diets with soybean meal. Animals in the experimental groups received diets in which a portion of the soybean meal was replaced with FRSM and/or FSBM: group FR—8% FRSM; group FR/FS—6% FRSM and 2% FSBM; group FS/FR—2% FRSM and 6% FSBM; and group FS—8% FSBM. Group FR/FS showed an increase in total antioxidant potential of plasma (FRAP) and low-molecular-weight antioxidants, i.e., vitamin C, urea, uric acid, and albumin, as well as an increase in catalase activity. Blood levels of lipid hydroperoxides (LOOH) and malonyl dialdehyde (MDA) were decreased. A reduction in lipid peroxidation due to the use of FR/FS was also indicated by a decrease in liver MDA and jejunum wall LOOH levels. Increases in superoxide dismutase (SOD) and catalase (CAT) activity and vitamin C levels in these tissues were also noted. The results of the study indicate that the inclusion of fermented rapeseed meal in the diet (6%) in combination with soybean meal (2%), improved the redox status of the weaners.

Fastness and antibacterial properties of polypropylene surgical face masks dyed with coffee grounds

The Covid-19 epidemic has affected all aspect of daily life, from health and education, to even the way we shop. In the light of the epidemic, one decision has been to require surgical face masks in all public areas, including hospitals, schools, shopping centers and even in the street. Most consumers have chosen to wear colored surgical face masks to match their clothes. However, these colored surgical face masks have been dyed using synthetic dyestuff. This dyestuff contains toxic mutagenic, allergic and carcinogenic substances. This study aims to dye surgical facemask using natural colorants to investigate color fastness to perspiration, changes of color for each dyeing process (CIELAB) and the antibacterial activity of surgical face masks dyed using coffee grounds. During the dyeing process, three different types of mordant were used. The control sample was dyed using coffee grounds, without the use of mordant. Results found that coffee grounds can serve as a potential source of natural dye for coloring textile materials. Nonwoven samples showed good levels of fastness and antibacterial activity.

Combination of sonication with anti‐browning treatments as a strategy to increase the shelf life of fresh‐cut potatoe (cv. Monalisa)

Two antioxidant solutions, a patented mixture based on vitamin C and other compounds (Natureseal®, MV) and green tea extract (GT), were proposed to prevent browning in sliced potatoes. Combination with ultrasound (US) at two frequencies (35 and 130 kHz) was also evaluated, but no significant enhancement of the effects was detected with US. In MV-treated samples, respiration rate and dry matter (19.7%) were higher than they were in the control (CK) (17.3%) or GT-treated samples (16.8%). Neither membrane integrity nor malondialdehyde content was significantly affected by the addition of MV or GT, but in MV samples the antioxidant activity was increased sixfold at the beginning of the storage (39.1 mmol ascorbic acid equivalents/kg), but decreased after 9 days. A yellowish coloration on the surface of GT samples (L*a*b* values being 68.3, −6.4, and 25.3, respectively), attributed to the coloration of the tea concentrate, was observed. In the conditions studied, GT was not able to delay browning in potatoe slices. In contrast, MV solution preserved the original color of the sliced potatoes (69.6, −6.7, and 27.7 for L*a*b*, respectively), during the 9-day storage at 4°C. Novelty Impact Statement Sulfites are used as an additive to maintain food color, shelf life, and prevent the growth of fungi or bacteria. However, they are considered as allergenic substances. The study proves the efficacy of vitamin C as a substitute to sulfites to preserve fresh-cut potatoes and delay their browning.

Heating Effect on Protein’s Aggregation in Goat and Bovine Milk Based on One and Two-Dimensional Polyacrylamide Gel Electrophoresis

Goat milk has been considered as a possible alternative of bovine milk because of hypoallergenic. The milk protein is the major allergenic substances, however, the differences of proteins have been few demonstrated in processing between goat and bovine milk. To explore the influence of three heat treatment and ultrahigh pressure (UHP, at 500 MPa and 17 °C) on milk, we investigated the differences of proteins in the two types of milk by one and two-dimensional polyacrylamide gel electrophoresis (1D and 2D PAGE) methods. β-lactoglobulin (β-LG) from goat milk showed one big band and migrated slower than α-lactalbumin (α-LA) on the native gel; while bovine milk showed two β-LG bands that had higher mobility ratio than other protein bands. The pasteurizing (63 °C, 30 min) and UHT (143 °C, 15 s) led to no obvious missing of protein bands, but the boiling treatment (100 °C, 3 min) caused binding of whey protein with κ-CN and αs2-CN in both types of milk. UHP treatment of milk also causes β-LG aggregates with casein by forming disulfide-bonded. All of the treatments indicated that goat milk was more sensitive to heat and pressure than bovine milk to form the aggregates and heat processing had the greatest effect on β-LG. This study could be helpful in understanding the difference in technological-functional properties of the two types of milk.

Efficacy Analysis of Glucocorticoids in the Treatment of Allergic Purpura in Tibetan Children

Background: Henoch Schonlein Purpura (HSP) is a common immune-related allergic disease in children. It is very important to understand the clinical features of this disease for doctors. Objective: To explore the clinical efficacy of glucocorticoids in the treatment of HSP in Tibetan children at high altitude, and to analyze the possible causes of HSP in children at high altitude. The risk factors of the disease provide a reference for the treatment of HSP in children in high altitude areas. Methods: Selecting January 2015 to November 2020, 88 children diagnosed with Henoch-Schonlein Purpura in the outpatient and inpatient departments of the People’s Hospital of Bomi County, Tibet Autonomous Region were the subjects of the study. Its gender, age of onset, season of onset, predisposing factors, allergy history, first symptoms, clinical manifestations, laboratory examinations, etc., perform retrospective analysis. Results: Among 88 children with allergic purpura, 55 were boys, accounting for 62.5%, and 33 were girls, accounting for 37.5%. Men have more cases than women. All have clinical manifestations of purpura of the skin, among which 35 cases have obvious triggers, of which the above there were 26 cases of respiratory infections, 6 cases of dietary factors, and 3 cases of contact with allergic substances. Simple skin type: 18 cases, accounting for 20.45%; Abdominal type: 6 cases, accounting for 6.82%; 2 male cases, accounting for 33.33%; 4 female cases, accounting for 66.67%; Articular type: 8 cases, accounting for 33.33%; Renal type: 2 cases, accounting for 2.27%; 54 cases of mixed type, accounting for 61.36%. After glucocorticoids, the rashes disappeared, no any adverse reactions. Conclusion: Allergic purpura in children is more common in school-age children, and upper respiratory tract infection is the main predisposing factor. Skin purpura is the main clinical manifestation, often associated with lower extremity joint swelling and pain. There is no significant difference in the efficacy and course of the disease between intravenous and oral treatment. Therefore, clinicians should strictly grasp the indications of glucocorticoids to reduce the occurrence of complications.

A Systematic Review of Food Allergy: Nanobiosensor and Food Allergen Detection.

Several individuals will experience accidental exposure to an allergen. In this sense, the industry has invested in the processes of removing allergenic compounds in food. However, accidental exposure to allergenic proteins can result from allergenic substances not specified on labels. Analysis of allergenic foods is involved in methods based on immunological, genetic, and mass spectrometry. The traditional methods have some limitations, such as high cost. In recent years, biosensor and nanoparticles combined have emerged as sensitive, selective, low-cost, and time-consuming techniques that can replace classic techniques. Nevertheless, each nanomaterial has shown a different potential to specific allergens or classes. This review used Preferred Reporting Items for Systematic Reviews and the Meta-Analysis guidelines (PRISMA) to approach these issues. A total of 104 articles were retrieved from a standardized search on three databases (PubMed, Scopus and Web of Science). The systematic review article is organized by the category of allergen detection and nanoparticle detection. This review addresses the relevant biosensors and nanoparticles as gold, carbon, graphene, quantum dots to allergen protein detection. Among the selected articles it was possible to notice a greater potential application on the allergic proteins Ah, in peanuts and gold nanoparticle-base as a biosensor. We envision that in our review, the association between biosensor and nanoparticles has shown promise in the analysis of allergenic proteins present in different food samples.

Is there a role of toothpastes in the development of recurrent aphthous stomatitis? A prospective controlled clinical trial with skin patch testing

The oral mucosa is exposed to a large number of antigenic agents contained in toothpastes. These agents are reported to stimulate recurrent aphthous stomatitis (RAS) pathogenesis, and toothpastes that do not contain probable allergenic substances reduced the number and frequency of aphthous ulcers. We aimed to determine whether the skin patch test (SPT) can be used to determine if toothpaste allergens play a role in the etiology of RAS. Sixty-three patients with RAS and 47 healthy volunteers were skin patch tested with sodium lauryl sulfate, cocamidopropyl betaine, propylene glycol, aluminum chloride hexahydrate, menthol, triclosan, and titanium dioxide, which are present in most of the toothpastes. Fisher's exact test and the Yates chi-square test were used to compare categorical variables and patch test results between 2 groups. The SPT was positive in 8 (22.2%) patients with RAS and 11 (23.4%) control subjects, and the difference between the groups was not statistically significant (P < .05). Sodium lauryl sulfate, titanium dioxide, and menthol were the most common positive allergens in both groups. Allergens in toothpastes did not appear to stimulate the formation of RAS. However, in order to determine a clearer relationship, a study in a larger patient series employing intraoral patch testing with more toothpaste ingredients is suggested.

Allergic Anaphylactic Risk in Farming Activities: A Systematic Review.

Allergic disorders in the agriculture sector are very common among farm workers, causing many injuries and occupational diseases every year. Agricultural employees are exposed to multiple conditions and various allergenic substances, which could be related to onset of anaphylactic reactions. This systematic review highlights the main clinical manifestation, the allergens that are mostly involved and the main activities that are usually involved. This research includes articles published on the major databases (PubMed, Cochrane Library, Scopus), using a combination of keywords. The online search yielded 489 references; after selection, by the authors, 36 articles (nine reviews and 27 original articles) were analyzed. From this analysis, the main clinical problems that were diagnosed in this category were respiratory (ranging from rhinitis to asthma) and dermatological (eczema, dermatitis, hives) in nature, with a wide symptomatology (from a simple local reaction to anaphylaxis). The main activities associated with these allergic conditions are harvesting or cultivation of fruit and cereals, beekeepers and people working in greenhouses. Finally, in addition to the allergens already known, new ones have emerged, including triticale, wine, spider and biological dust. For these reasons, in the agricultural sector, research needs to be amplified, considering new sectors, new technologies and new products, and ensuring a system of prevention to reduce this risk.

Dermatitis de contacto alérgica e irritativa en región vulvar. Impacto de los jabones íntimos

La dermatitis de contacto vulvar es un problema común en dermatología y ginecología; afecta de manera importante la salud y la calidad de vida de las mujeres que la padecen. Más del 50% de los casos de prurito vulvar crónico en mujeres adultas puede ser atribuido a sustancias irritantes y alérgenos, entre ellos los denominados jabones íntimos, cuyo uso es cada vez más frecuente. El principal síntoma de la dermatitis es irritación en la región vulvar; puede presentar síntomas como prurito, ardor y dolor. La dermatitis de contacto se produce después de la exposición a irritantes exógenos o alérgenos. Clínicamente son difíciles de diferenciar estas dos entidades; se requiere realizar una adecuada historia clínica, que indague sobre posibles alérgenos, realizar un examen físico completo y una prueba de parche, único método diagnóstico que confirma la dermatitis alérgica por contacto, para realizar un diagnóstico acertado e iniciar un tratamiento adecuado y eliminar el factor desencadenante.

Damage Analysis of Tattoo Needle Tips

Abstract Tattooing is becoming more and more accepted at different levels of society today. A contributor to this is that besides body decoration, the cosmetics industry is increasingly using it for make-up tattoos and to hide skin imperfections and surgical scars. Tattoo needles, despite being in direct contact with human tissues and even with blood, are not subject to current Medical Device Regulation, so they do not require a number of material and biocompatibility tests in order to be placed on the market. The focus of our research was on how the needle and the soldering of the needles are damaged during tattooing, and how this develops over time, as a worn needle tip can not only degrade the quality of the tattoo, but also increase skin breakdown and the amount of dissolving allergenic substances.

New aspect of allergic contact dermatitis, an inflammatory skin disorder mediated by mast cells: Can IL-38 help?

Atopic dermatitis (AD) is an inflammatory reaction of the skin that can occur in several parts of the body and can be provoked or exacerbated by food and/or environmental compounds. Allergic contact dermatitis (ACD) is a potential enhancer of AD, and an epidermal barrier breaker which induces greater penetration of allergens and other compounds. ACD presents an eczematous rash, red and itchy, with inflammation mediated by cytokines. ACD is an immunological disorder caused by contact with an allergic substance (haptens) that involves immunotoxicity, irritation and inflammation. Mast cells (MCs) are important immune cells that intervene, as effector cells, in allergic and anaphylactic reactions, asthma, autoimmune diseases and cancer. In dermatitis, activated MCs release inflammatory chemical mediators and secrete pro-inflammatory cytokines, including interleukin (IL)-1, TNF, and IL-33. In addition, IL-1 activates MCs to generate a number of cytokines and chemokines, which aggravate inflammation. IL-38 cytokine, an IL-1 family member, is secreted by activated immune cells, including macrophages and lymphocytes, and possesses anti-inflammatory activity. IL-38, by binding IL-36 receptor (IL-36R), provokes suppression of inflammation in many immune diseases. In particular, IL-38 inhibits the generation of IL-1, IL-6 and IL-8 along with other cytokines/chemokines. Here, we hypothesize for the first time that IL-38 may suppresses the inflammatory response in dermatitis, exerting beneficial therapeutic effect.

Time-correlated Single Ion Counting Mass Spectrometer with Long and Short Time-of-Flight Tubes and an Evaluation of Its Performance for Use in Trace Analysis of Allergenic Substances.

An analyte molecule was ionized using a femtosecond laser as the ionization source and was measured by a twin-type time-of-flight mass spectrometer with long (42 cm) and short (6.4 cm) flight tubes. The signal was measured using an analog signal digitizer and a time-correlated single ion counting system, and performance was evaluated by comparing data obtained from both instruments. The short mass spectrometer had a mass resolution of 450 and was used in the trace analysis of allergenic substances in a fragrance.