Formaldehyde In Products Research Articles

Micronucleus frequency in exfoliated buccal cells from hairdresser who expose to hair products

Background: Hairdresser is one of the fastest growing occupations in today’s society. Hairdresser help styling, cutting, colouring, perming, curling, straightening hair and various treatment to customer. Somehow, hairdresser are constantly exposed to chemical substances such as aromatic amines, hydrogen peroxide, thioglycolic acid, formaldehyde in hair products which can cause damage to human’s genome. Micronucleus is one of the effective biomarker for processes associated with the induction of DNA damage. Purpose: The aim of this study was to determine the micronucleus frequencies in buccal mucosa epithelial cells of hairdresser who were exposed to chemical of hair products. Method: This study was conducted on twenty female subjects, who were divided into 2 groups: exposed and non-exposed (control) group. All subjects recruited were working in the same beauty salon. Buccal cells were obtained from each individual by using cytobrush. The cells were stained with modified Feulgen-Ronssenback method and counting of micronucleus per 1000 cell was done under light microscope. The data were analyzed using independent t-test and one-way Anova (p<0.05). Result: The result showed a significant difference in micronucleus frequency between 2 groups. There were a significantly increase of micronucleus frequency in hairdressers and increase of micronucleus frequency with the longer duration of exposure. Conclusion: It concluded that the chemical substances of hair products had affected the micronucleus frequency ofthe epithelial cells in buccal mucosa of hairdressers.

Separation and analysis of trace volatile formaldehyde in aquatic products by a MoO₃/polypyrrole intercalative sampling adsorbent with thermal desorption gas chromatography and mass spectrometry.

An in situ embedded synthesis strategy was developed for the preparation of a MoO3 /polypyrrole intercalative sampling adsorbent for the separation and analysis of trace volatile formaldehyde in aquatic products. Structural and morphological characteristics of the MoO3 /polypyrrole intercalative adsorbent were investigated by a series of characterization methods. The MoO3 /polypyrrole sampling adsorbent possessed a higher sampling capacity and selectivity for polar formaldehyde than commonly used commercial adsorbent Tenax TA. Finally, the MoO3 /polypyrrole adsorbent was packed in the thermal desorption tube that was directly coupled to gas chromatography with mass spectrometry for the analysis of trace volatile formaldehyde in aquatic products. Trace volatile formaldehyde from real aquatic products could be selectively sampled and quantified to be 0.43-6.6 mg/kg. The detection limit was achieved as 0.004 μg/L by this method. Good recoveries for spiked aquatic products were achieved in range of 75.0-108% with relative standard deviations of 1.2-9.0%.

Formaldehyde may be found in cosmetic products even when unlabelled.

Concomitant contact allergy to formaldehyde and formaldehyde-releasers remains common among patients with allergic contact dermatitis. Concentration of free formaldehyde in cosmetic products within allowed limits have been shown to induce dermatitis from short-term use on normal skin.The aim of this study was to investigate the formaldehyde content of cosmetic products made in Lithuania. 42 samples were analysed with the chromotropic acid (CA) method for semi-quantitative formaldehyde determination. These included 24 leave-on (e.g., creams, lotions) and 18 rinse-off (e.g., shampoos, soaps) products. Formaldehyde releasers were declared on the labels of 10 products. No formaldehyde releaser was declared on the label of the only face cream investigated, but levels of free formaldehyde with the CA method was >40 mg/ml and when analysed with a high-performance liquid chromatographic method – 532 ppm. According to the EU Cosmetic directive, if the concentration of formaldehyde is above 0.05% a cosmetic product must be labelled “contains formaldehyde“. It could be difficult for patients allergic to formaldehyde to avoid contact with products containing it as its presence cannot be determined from the ingredient labelling with certainty. The CA method is a simple and reliable method for detecting formaldehyde presence in cosmetic products.

The Research Progress of Endogenous Formaldehyde in Aquatic Products

Endogenous formaldehyde in aquatic products is a hot research topic, as it is an urgent problem to be solved. This paper summarized the advance in background concentration, generation mechanism and detection methods of endogenous formaldehyde in aquatic products, and the work in the future was prospected.

Determination of formaldehyde in aquatic products by a sensitive catalytic fluorescence method

A novel method for the determination of trace formaldehyde in food samples has been established using a catalytic kinetic fluorimetry technique. It is based on the fact that the oxidation of pyronine Y by sodium periodate is catalyzed by formaldehyde in phosphoric acid. When the excitation wavelength was set at 546 nm, it was observed that decreased intensity (ΔF) of fluorescence at 563 nm was proportional to the concentration of formaldehyde in the range 0 to 0.30 μg mL−1. The limit of detection and the average recovery for formaldehyde were 2.0 × 10−2 ng mL−1 and 101.3% (n = 6), respectively. The present method has been applied to the determination of trace formaldehyde in aqueous products and the results observed were in good agreement with those obtained by distillation-spectrophotometry. A review of recently published catalytic or inhibiting kinetic methods for the determination of HCHO is presented for comparison. The mechanism of reaction is studied.

Study on Formaldehyde Migration Rules in Products of Tripolycyanamide for Food Packaging

In this work we studied the migration amount of formaldehyde in products of tripolycyanamide for food packaging. In order to review the rule of products of tripolycyanamide for food packaging, with different stimulant solutions, simulated temperatures and soaking time, the migration quantities of formaldehyde in products of tripolycyanamide for food packaging into deionized water, 3% acetic acid and 15% ethanol were measured by phenylhydrazine hydrochloride spectrophotometry. The amounts of formaldehyde migrated to 3 % acetic acid was higher than those of 15 % ethanol. Espousing in higher temperature , amount of formaldehyde of the products of tripolycyanamide were migrated more. And the total migrations of formaldehyde in three exposures was beyond the EU specific migration limits for formaldehyde (15 mg/L ).With the higher temperature exposure was done , the amount of formaldehyde migration reaches maximum in lower number of repeated exposures. We also discussed the formaldehyde migration rule for different surface roughness of food packaging materials.

Analysis of free and bound formaldehyde in squid and squid products by gas chromatography–mass spectrometry

Formaldehyde can be added illegally as a food preservative in addition to the endogenous formaldehyde that naturally occurs in aquatic products. In this study, formaldehyde was derivatized from 2,4-dinitrophenylhydrazine and analyzed using gas chromatography–mass spectrometry to investigate free and reversibly bound formaldehyde in 10 squid and squid products. The results were compared to those obtained by high-performance liquid chromatography (HPLC). The limit of detection was 2.0 mg/kg. The total concentrations of free and reversibly bound formaldehyde were, on average, higher than the free formaldehyde concentration by 26.6 mg/kg. Free formaldehyde made up, on average, 39% of total free and reversibly bound formaldehyde. The sum of the concentrations of free and reversibly bound formaldehyde was, on average, higher than the free formaldehyde concentration by 19.3 mg/kg in the HPLC method. Free formaldehyde made up an average of 39% of total free and reversibly bound formaldehyde in the HPLC method. The use of gas chromatography–mass spectrometry to detect formaldehyde in aquatic products allowed confirmation through retention time and molecular mass information. The monitoring of free formaldehyde in aquatic products and proper control of the manufacturing process could help to reduce the formaldehyde level in shredded squid products. Finally, exposure to formaldehyde from consumption of shredded squid was estimated: it was less than 0.2 mg/kg, which is the oral reference dose suggested by the US Environmental Protection Agency.

Determinação de formol em amostras de produtos de alisamento capilar

The objective of the present work was to determine the contents of formol (formaldehyde) in hair-straightening products used in various beauty salons. Formol can cause damages to hair, it is also toxic and carcinogenic in the medium term. Despite being banned by the Brazilian Health Surveillance Agency (ANVISA) it is frequently utilized, being disguised with flavorings, and its presence is not noted on product labels. Therefore, the study was intended to evaluate levels of formol in samples taken in the city of Rolandia (Paraná State, Brazil), where the surveillance does not always take place. The determined values ranged from 5.37 to 10.65 %.

Formaldehyde in hair straightening products: Rapid 1H NMR determination and risk assessment

Despite official regulations, the illegal use of formaldehyde-containing or releasing hair straightening products has become a popular practice in Europe and high contents of formaldehyde in such products have been reported. In this study, a methodology utilizing (1)H NMR spectroscopy has been developed to measure the concentration of formaldehyde in hair straightening products. For sample preparation, a dilution and alkaline hydrolysis is required. The total formaldehyde content can then be quantified by a distinct peak of the CH2 group of the methanediol molecule in the δ4.84-4.82 ppm range. The developed methodology was applied for the analysis of 10 hair straightening products. Seven of these products contained detectable amounts of formaldehyde that were higher than the maximum allowed concentration of 0.2%. The formaldehyde content of these products was found to be in the range 0.42-5.83% with an average concentration of 1.46%. The accuracy and reliability of the NMR results were confirmed by the EU reference photometric method. The air formaldehyde concentrations after application of hair straightening products were estimated in ranges 20-423 ppm and 1-18 ppm (for 1 and 24 m(3) salon volume). A probabilistic exposure estimation using Monte Carlo simulation found the average formaldehyde concentration to be 6 ppm (standard deviation 15 ppm). All exposure scenarios considerably exceeded the safe level of 0.1 ppm. Our findings confirmed that the risk of cosmetic formulations with formaldehyde above 0.2% is not negligible, as these products may facilitate considerable exposure of formaldehyde for consumers especially for salon workers.

Determination of formaldehyde in aquatic products by micellar electrokinetic capillary chromatography with 2,4-dinitrophenylhydrazine derivatization

Summary Formaldehyde in aquatic products was determined by micellar electrokinetic capillary chromatography (MEKC) after derivatization with 2,4-dinitrophenylhydrazine. Separation was carried out at 25 °C and 25 kV, using a fused silica capillary (75 µ internal diameter; 50.5 cm effective length) and an ultraviolet detector set at 360 nm. The optimal background electrolyte was 20 mM sodium tetraborate and 20 mM sodium dodecyl sulfate at pH 9.0 with 3 s hydrodynamic injection at 30 mbar. Electrophoretic analysis took approximately 6.5 min. The correlation coefficient of the calibration curve was 0.999 over the concentration range 2.0–100.0 mg L−1, and the LOD and LOQ values were 0.57 and 1.89 µg mL−1, respectively. The recoveries were from 83.7% to 97.2% with steam distillation as the sample pretreatment method.

High-performance thin-layer chromatographic analysis of psoralen in marketed formulations and manufactured solid lipid nanoparticles (SLNs): Validation of the method

Summary Formaldehyde in aquatic products was determined by micellar electrokinetic capillary chromatography (MEKC) after derivatization with 2,4-dinitrophenylhydrazine. Separation was carried out at 25 °C and 25 kV, using a fused silica capillary (75 µ internal diameter; 50.5 cm effective length) and an ultraviolet detector set at 360 nm. The optimal background electrolyte was 20 mM sodium tetraborate and 20 mM sodium dodecyl sulfate at pH 9.0 with 3 s hydrodynamic injection at 30 mbar. Electrophoretic analysis took approximately 6.5 min. The correlation coefficient of the calibration curve was 0.999 over the concentration range 2.0–100.0 mg L−1, and the LOD and LOQ values were 0.57 and 1.89 µg mL−1, respectively. The recoveries were from 83.7% to 97.2% with steam distillation as the sample pretreatment method.

화장품 중 포름알데히드 함유량 조사

포름알데히드는 그 자체가 보존제로 또는 다른 보존제로부터 유리된 형태로 화장품에 일반적으로 존재한다. 포름알데히드는 낮은 농도로도 민감한 피부 반응을 일으킬 수 있으므로 화장품에서 그 사용을 규제하고 있다. 본 연구에서는 팩 및 마스크와 같은 화장품 114 품목을 시중에서 구입하여 포름알데히드의 함량을 분석하였다. 검사 품목의 36%에서 <TEX>$0.3{\sim}9.7{\mu}g/mL$</TEX> (ppm) 수준의 포름알데히드가 검출되었다. 포름알데히드 유리 보존제를 함유한다고 표시되어 있는 12개 제품의 포름알데히드 함량을 조사하였다. Imidazolidinyl urea를 사용한 화장품 10품목과 1,3-Dimethylol-5,5-dimethylhydantoin (DMDM hyantoin)을 사용한 화장품 2품목에서 평균 <TEX>$1.7{\mu}g/mL$</TEX> (ppm)의 포름알데히드가 검출되었다. 식품의약품안전청 고시 최대 허용 포름알데히드 농도 0.2 % (2,000 ppm)을 고려할 때, 이번 조사에서 분석한 화장품에서는 비교적 낮은 수준의 포름알데히드 함량을 보였다. Formaldehyde is commonly present in cosmetic products as an ingredient intended to preserve cosmetic raw materials or as a liberated product from other formaldehyde-releasing preservatives. Since even low level of formaldehyde can elicit a dermatological reactions in sensitized individuals, there has been a tendency to restrict and regulate the use of formaldehyde in cosmetic products. In this study, we determined formaldehyde content in 114 commercial cosmetic products such as packs and masks. Formaldehyde was detected at the level ranging from 0.3 to <TEX>$9.7{\mu}g/mL$</TEX> (ppm) in 36 % of the tested cosmetic products. We investigated formaldehyde content of twelve products specifying to contain formaldehyde-releasing preservatives on their labels. In eleven of ten imidazolidinyl urea-containing and two 1,3-Dimethylol-5,5-dimethylhydantoin (DMDM hyantoin)-containing products, average of <TEX>$1.7{\mu}g/mL$</TEX> (ppm) formaldehyde level was detected. The formaldehyde levels detected in our tested products are low when compared with the maximum authorised concentration 0.2 % (2000 ppm) of formaldehyde in cosmetics according to the Korean Food and Drug Administration notice.

Studies of the Gas Phase Reactions of Linalool, 6-Methyl-5-hepten-2-ol and 3-Methyl-1-penten-3-ol with O3and OH Radicals

The reactions of three unsaturated alcohols (linalool, 6-methyl-5-hepten-2-ol, and 3-methyl-1-penten-3-ol) with ozone and OH radicals have been studied using simulation chambers at T ∼ 296 K and P ∼ 760 Torr. The rate coefficient values (in cm(3) molecule(-1) s(-1)) determined for the three compounds are linalool, k(O3) = (4.1 ± 1.0) × 10(-16) and k(OH) = (1.7 ± 0.3) × 10(-10); 6-methyl-5-hepten-2-ol, k(O3) = (3.8 ± 1.2) × 10(-16) and k(OH) = (1.0 ± 0.3) × 10(-10); and 3-methyl-1-penten-3-ol, k(O3) = (5.2 ± 0.6) × 10(-18) and k(OH) = (6.2 ± 1.8) × 10(-11). From the kinetic data it is estimated that, for the reaction of O(3) with linalool, attack at the R-CH═C(CH(3))(2) group represents around (93 ± 52)% (k(6-methyl-5-hepten-2-ol)/k(linalool)) of the overall reaction, with reaction at the R-CH═CH(2) group accounting for about (1.3 ± 0.5)% (k(3-methyl-1-penten-3-ol)/k(linalool)). In a similar manner it has been calculated that for the reaction of OH radicals with linalool, attack of the OH radical at the R-CH═C(CH(3))(2) group represents around (59 ± 18)% (k(6-methyl-5-hepten-2-ol)/k(linalool)) of the total reaction, while addition of OH to the R-CH═CH(2) group is estimated to be around (36 ± 6)% (k(3-methyl-1-penten-3-ol)/k(linalool)). Analysis of the products from the reaction of O(3) with linalool confirmed that addition to the R-CH═C(CH(3))(2) group is the predominant reaction pathway. The presence of formaldehyde and hydroxyacetone in the reaction products together with compelling evidence for the generation of OH radicals in the system indicates that the hydroperoxide channel is important in the loss of the biradical [(CH(3))(2)COO]* formed in the reaction of O(3) with linalool. Studies on the reactions of O(3) with the unsaturated alcohols showed that the yields of secondary organic aerosols (SOAs) are higher in the absence of OH scavengers compared to the yields in their presence. However, even under low-NO(X) concentrations, the reactions of OH radicals with 3-methyl-1-penten-3-ol and 6-methyl-5-hepten-2-ol will make only a minor contribution to SOA formation under atmospheric conditions. Relatively high yields of SOAs were observed in the reactions of OH with linalool, although the initial concentrations of reactants were quite high. The importance of linalool in the formation of SOAs in the atmosphere requires further investigation. The impact following releases of these unsaturated alcohols into the atmosphere are discussed.

A novel miniaturised electrophoretic method for determining formaldehyde and acetaldehyde in food using 2-thiobarbituric acid derivatisation

A novel miniaturised capillary electrophoresis with electrochemical detection (mini-CE-ED) method has been developed for fast determination of formaldehyde (FA) and acetaldehyde (AA) in several food products without preconcentration. Because FA and AA usually exist as uncharged molecules with zero electrophoretic mobility, plus the fact that these two compounds lack of chromophore for sensitive ultraviolet (UV) detection, effective and sensitive determination of FA and AA in real samples is often a challenging task. In this work, an electroactive compound 2-thiobarbituric acid (TBA) was selected as the ideal derivatisation reagent to facilitate the electrochemical determination of FA and AA. Under the optimum conditions, FA-TBA and AA-TBA adducts can be well separated by mini-CE-ED with low detection limit of 9.10 × 10 −9 g/mL (13.2 fg) for FA (S/N = 3). The proposed method should find a wide range of analytical applications in food products as an alternative to conventional and microchip CE approaches.

수산물 중 포름알데히드 함량분석

수산물 중 포름알데히드 함량 수준을 평가하기 위하여 어류, 패류, 갑각류 및 연체류 14종을 비교 분석하였다. 수산물 중 포름알데히드 함량은 0.07 mg/kg에서 최고 73.74 mg/kg 수준으로 측정되었다. 어류에서의 함량은 평균 1.29 mg/kg, 패류에서의 함량은 평균 1.70 mg/kg, 갑각류의 경우 평균 7.90 mg/kg으로 어류와 패류에 비교해 유의적으로 높았으며, 특히 꽃게의 경우 최대 73.74 mg/kg까지 함유되어 있었다. 연체류에서의 함량은 평균 3.06 mg/kg수준으로 평가되었다. 유통형태에 따른 함량에서는 대체적으로 살아있는 상태로 유통되는 활어나 활패의 경우 냉장, 냉동 유통보다 낮은 함량을 보였다. 이는 포름알데히드가 사후에 여러 가지 복잡한 과정을 거쳐서 생성되는 것과 함께 수산물에 특이적인 물질인 TMAO가 사후 효소분해 등의 여러 기작을 통해 DMA와 포름알데히드로 분해되어 증가하기 때문인 것(18-21)으로 사료된다. '국민영양조사'와 '영양 및 위해평가 시스템 구축' 연구보고서를 참고하여 노출량 평가를 한 결과, 대상 수산물에 대한 한국인의 평균 일일 섭취량으로 섭취되는 포름알데히드는 0.070 mg/day로 ADI의 0.58% 수준밖에 되지 않았으며, 극단적인 섭취량 평가를 위한 99th 수준에서 섭취되는 포름알데히드는 1.574 mg/day로 ADI의 13.12%에 불과하여 안전한 수준이지만, 더 정확한 노출량 평가를 위해서는 다른 수산물을 포함한 식품에 대한 포름알데히드 함량의 조사와 더불어 섭취량 조사 또한 뒷받침되어야 할 것으로 판단된다. In this study, formaldehyde in various fisheries products was previously derivatized with acetylacetone and subsequently analyzed by using HPLC-PDA. The formaldehyde contents ranged from 0.07 to 73.74 mg/kg. The compound was significantly higher in both mollusks (0.34-12.38 mg/kg) and crustaceans (0.09-73.74 mg/kg) than in fish (0.07-3.35 mg/kg) and shellfish (0.50-3.90 mg/kg). This difference was due to storage time and temperature. In general, fish and shellfish are sold live or in refrigerated form with shorter a shelf-life, but mollusks and crustaceans are distributed in cold or frozen systems with a longer shelf-life. Using food intake data from a report of the National Health and Nutrition Survey, the daily human exposure level to formaldehyde was 0.58% of the ADI. The results from this study might provide fundamental information to confirm naturally-originating or fraudulent formaldehyde treatment in fisheries products.

Alcohol oxidase- and formaldehyde dehydrogenase-based enzymatic methods for formaldehyde assay in fish food products

For Gadoid fishes, formaldehyde can be generated in tissues in huge amounts during endogenous enzymatic degradation of natural osmoprotectant trimethylamine-N-oxide. This paper describes two enzymatic methods for assay of formaldehyde in fish food products using alcohol oxidase (AOX) and formaldehyde dehydrogenase (FdDH) isolated from the thermotolerant methylotrophic yeast Hansenula polymorpha. AOX-based method exploits an ability of the enzyme to oxidise a hydrated form of formaldehyde to formic acid and hydrogen peroxide monitored in peroxidase-catalysed colorimetric reaction. In FdDH-based method, a monitored coloured formazane is formed from nitrotetrazolium salt during reduction by NADH, produced in formaldehyde-dependent reaction. It was demonstrated an applicability of both methods for assay of formaldehyde in fish products. The optimal protocols for analysis procedures have been elaborated and analytical parameters of both enzymatic methods have been established. The both methods were demonstrated that some fish products (hake and cod) contain high formaldehyde concentrations (up to 100mg/kg wet weight).

Ultrasound-assisted emulsification microextraction with simultaneous derivatization coupled to fibre optics-based cuvetteless UV–vis micro-spectrophotometry for formaldehyde determination in cosmetic samples

In this work, ultrasound-assisted emulsification microextraction in combination with fibre optics-based cuvetteless UV–vis micro-spectrophotometry has been proposed as a novel method for the determination of formaldehyde in water-based cosmetics such as shampoo, conditioner and shower gel. The use of a powerful cup-horn sonoreactor allows simultaneous extraction and derivatization of the samples without any pre-treatment. The type and volume of organic extractant solvent, need for a disperser solvent, sonication conditions (sonication time and amplitude), ionic strength and centrifuging time have been carefully studied. Matrix effects were also evaluated. The European official method for quantification of formaldehyde in cosmetic products was used for comparison purposes. An important improvement in sensitivity and sample throughput as well as miniaturization was achieved. A limit of detection of 0.02 μg g −1 of formaldehyde and a repeatability expressed as relative standard deviation of 5.9% were obtained.

Formaldehyde‐releasers: relationship to formaldehyde contact allergy. Contact allergy to formaldehyde and inventory of formaldehyde‐releasers

This is one of series of review articles on formaldehyde and formaldehyde-releasers (others: formaldehyde in cosmetics, in clothes and in metalworking fluids and miscellaneous). Thirty-five chemicals were identified as being formaldehyde-releasers. Although a further seven are listed in the literature as formaldehyde-releasers, data are inadequate to consider them as such beyond doubt. Several (nomenclature) mistakes and outdated information are discussed. Formaldehyde and formaldehyde allergy are reviewed: applications, exposure scenarios, legislation, patch testing problems, frequency of sensitization, relevance of positive patch test reactions, clinical pattern of allergic contact dermatitis from formaldehyde, prognosis, threshold for elicitation of allergic contact dermatitis, analytical tests to determine formaldehyde in products and frequency of exposure to formaldehyde and releasers. The frequency of contact allergy to formaldehyde is consistently higher in the USA (8-9%) than in Europe (2-3%). Patch testing with formaldehyde is problematic; the currently used 1% solution may result in both false-positive and false-negative (up to 40%) reactions. Determining the relevance of patch test reactions is often challenging. What concentration of formaldehyde is safe for sensitive patients remains unknown. Levels of 200-300 p.p.m. free formaldehyde in cosmetic products have been shown to induce dermatitis from short-term use on normal skin.

Microwave-Assisted Extraction Coupled Online with Derivatization, Restricted Access Material Cleanup, and High-Performance Liquid Chromatography for Determination of Formaldehyde in Aquatic Products

A rapid technique based on microwave-assisted extraction (MAE) coupled online with derivatization, restricted access material cleanup, and high-performance liquid chromatography (HPLC) was developed for the determination of formaldehyde in aquatic products. Formaldehyde was first extracted with water under the action of microwaves and then directly introduced into a derivatization reservoir containing 2,4-dinitrophenylhydrazine (DNPH). The formaldehyde-DNPH derivative (100 μL) was loaded into a restricted access material (RAM) precolumn for online cleanup. Subsequently, the analyte was transferred from the precolumn to an analytical column and determined by UV absorption spectrum at 352 nm. The limit of detection (LOD) was 0.27 mg kg(-1). The intraday and interday precisions expressed as RSDs were 3.5% and 5.0%, respectively. This method was applied to determine the presence of formaldehyde in various aquatic products. The results were in agreement with those obtained by the state standard method (steam-distillation and offline HPLC analysis) used in China and higher than those obtained by the online ultrasound-assisted extraction (UAE) method. The recoveries obtained by analyzing 11 spiked aquatic products were in the range of 70.0%-105.0%. The online technique was demonstrated to be rapid with little consumption of samples and reagents.

Rapid and sensitive determination of formaldehyde in some beverages and foods by flow‐injection fluorimetric analysis

SummaryA simple and sensitive flow‐injection (FI) method for rapid determination of formaldehyde in beverage and food products has been developed. Adopting stop‐flow technique, the proposed method distinctly improved the sensitivity of FI fluorimetric method for the determination of formaldehyde based on Hantzsch reaction with cyclohexane‐1,3‐dione. The fluorescent intensity was proportional to formaldehyde concentrations ranging 0.1 ng mL−1 to 1.000 μg mL−1, and the detection limit (S/N = 3) was 0.04 ng mL−1 of formaldehyde. The relative standard deviations (n = 11) for determination of 0.100 and 0.005 μg mL−1 of formaldehyde were 1.3% and 2.1%, respectively. The analytical frequency was 18 samples per hour. This method was applied directly for the determination of formaldehyde in diluted beverages and extraction solutions of foods, and the results obtained correlated well with those obtained by the standard method in which a sample pretreatment of steam distillation was required.