Determination Of Hydrazine In Water Research Articles

Aldehyde spiropyran fluorescent probe for rapid determination of hydrazine in environmental water

Hydrazine often receives publicity because it has a wide range of applications but high toxicity at the same time. Here, we invented a novel aldehyde spiropyran fluorescent probe (SP-CHO) for fluorescence determination of hydrazine. The probe was synthesized through a hydrolysis reaction and a condensation reaction. It exhibits a specific response to hydrazine. The influence factors and anti-interference ability of SP-CHO identifying hydrazine were studied. HRMS, 1 H NMR, and density functional theory (DFT) calculations were used to reveal the recognition mechanism. Results showed that SP-CHO can be used for fluorescence determination of hydrazine with high selectivity and sensitivity. An SP-CHO-based fluorescence method was established for quantitation of hydrazine. The detection limit was 1.26 μmol/l, and the linear range was 5-100 μmol/l. The determination of hydrazine in water samples can be completed within 10min, which shows good application prospects in real-time detection and process monitoring.

Simple Electrochemical Determination of Hydrazine in Water

Simple Electrochemical Determination of Hydrazine in Water

Ultrasensitive determination of hydrazine using a glassy carbon electrode modified with Pyrocatechol Violet electrodeposited on single walled carbon nanotubes

A glassy carbon electrode (GCE) was modified with pyrocatechol violet (PCV) that was electrodeposited on single walled carbon nanotubes (SWCNTs) via continuous cycling between 0 and 0.9 V (vs. SCE). The resulting electrode exhibits excellent electrocatalytic activity towards the oxidation of hydrazine at 0.3 V. The apparent surface coverage of the electrode is at least 24 times higher (2.7 × 10−10 mol cm−2) than that obtained with a bare GCE (1.1 × 10−11 mol cm−2). This is attributed to a remarkably strong synergistic effect between the acid-pretreated SWCNTs and the electrodeposited PCV coating. Response is fast (2 s) and sensitive (281 mA M−1 cm−2). Other features include a wide linear range (150 nM to 0.4 mM) and a low detection limit (150 nM at an SNR of 3). The sensor has been successfully applied to the determination of hydrazine in water and cigarette samples with good accuracy and precision. In addition, the morphology and the wetting properties of the coating were studied by scanning electromicroscopy and contact angle measurements.

Sensitive determination of hydrazine in water by gas chromatography–mass spectrometry after derivatization with ortho-phthalaldehyde

A gas chromatography–mass spectrometric (GC–MS) method has been established for the determination of hydrazine in drinking water and surface water. This method is based on the derivatization of hydrazine with ortho-phthalaldehyde (OPA) in water. The following optimum reaction conditions were established: reagent dosage, 40mgmL−1 of OPA; pH 2; reaction for 20min at 70°C. The organic derivative was extracted with methylene chloride and then measured by GC–MS. Under the established condition, the detection and the quantification limits were 0.002μgL−1 and 0.007μgL−1 by using 5.0-mL of surface water or drinking water, respectively. The calibration curve showed good linearity with r2=0.9991 (for working range of 0.05–100μgL−1) and the accuracy was in a range of 95–106%, and the precision of the assay was less than 13% in water. Hydrazine was detected in a concentration range of 0.05–0.14μgL−1 in 2 samples of 10 raw drinking water samples and in a concentration range of 0.09–0.55μgL−1 in 4 samples of 10 treated drinking water samples.

Disposable sensor for quantitative determination of hydrazine in water and biological sample

A method for determination of hydrazine is described. The sensor was constructed by immobilizing a reagent on TLC (Thin Layer Chromatography) paper. This procedure is based on chromogenic reaction of hydrazine with p-(dimethylamino)benzaldehyde (reagent) and formation of red colour product followed by scanner-based detection. Changes in RGB values of colour spots on TLC strips create a pattern. The obtained pattern was analyzed by MATLAB software. The proposed sensor is linear in concentration range of 10–300 μg mL−1 of hydrazine and has practical detection limit of 0.1 μg mL−1. Parameters such as pH and concentration of p-(dimethylamino)benzaldehyde were optimized. The proposed sensor was successfully applied for the determination of hydrazine in bovine serum and tap water.

Cloud point formation based on mixed micelle in the presence of electrolyte for extraction, preconcentration, and spectrophotometric determination of trace amounts of hydrazine in water and biological samples

A cloud point extraction process using mixed micelle of the anionic surfactant sodium dodecyl sulfate and the nonionic surfactant Triton X-114 to extract hydrazine from aqueous solutions was investigated. The method is based on the condensation reaction of hydrazine with p-(dimethylamino)benzaldehyde, azine formation, and mixed micelle-mediated extraction of azine in the presence of NaCl electrolyte as an inducing phase separation. An azine product was concentrated in surfactant-rich phase after separation. The optimal extraction and reaction conditions (e.g., surfactant, reagent and electrolyte concentrations, and centrifuge time) were studied and the analytical characteristics of the method (e.g., limit of detection, linear range, preconcentration, and improvement factors) were obtained. Linearity was obeyed in the range of 0.50–110 ng ml −1 of hydrazine and the detection limit of the method is 0.08 ng ml −1. The interference effect of some cations, anions, and organic compounds was also tested. The method was successfully applied to the determination of hydrazine in water and biological samples.

Kinetic fluorimetric determination of trace hydrazine in environmental waters

Two simple and sensitive methods for rapid determination of hydrazine in water are described, based on the inhibition effect of hydrazine on the reaction of oxyhalogen ion + halogen ion (X−) with rhodamine B in an acid medium. It is found that the linear range and the detection limit for the determination of hydrazine are 7.88–78.8 ng mL−1 and 1.7 ng mL−1, respectively, in the system of potassium chlorate in hydrochloric acid. They are 3.49–78.8 ng mL−1 and 0.81 ng mL−1, respectively, in the system of potassium bromate + potassium bromide in sulphuric acid solutions. Recoveries are in the range of 94–104%. A comparison was made for the analytical characteristics of different methods, and a possible reaction mechanism was proposed.

Extraction-chromatographic determination of hydrazine in natural water as a 5,7-Dinitrobenzofurazan derivative using diode-array detection

The conditions for the derivatization of hydrazine withp-dimethylaminobenzaldehyde and 4-chloro-5,7-dinitrobenzofurazan, extraction preconcentration of derivatives from natural water, and HPLC determination of the toxicant with diode-array detection were studied. The 5,7-dinitrobenzofurazan derivative was quantitatively extracted from water with isoamyl alcohol and a mixture of isoamyl alcohol with methylene chloride at pH 3–4. A procedure was developed for the extraction-chromatographic determination of hydrazine in water with cmin = 0.05 Μg/L and the analytical range 0.12-60 Μg/L. The concentration of hydrazine in lake Kaban water was determined.

Flow injection determination of hydrazine with fluorimetric detection

A spectrophotometric flow injection system is described for the determination of hydrazine, involving oxidation of hydrazine by thallium(III) with concomitant formation of thallium(I). The optimum analytical conditions have been established. The linear range for hydrazine is 25–500 ng ml −1 with a detection limit of 20 ng ml −1. The sampling frequency is 40±5 samples h −1. The relative standard deviation for 100, 250 and 500 ng ml −1 is 3.5, 2.6 and 1.8%, respectively. The method has been applied to the determination of hydrazine in water.

Use of a silver-gelatin complex for the determination of micro-amounts of hydrazine in water

Gelatin forms a weak complex with silver(I) in alkaline media. This complex was studied and was found to be suitable for the spectrophotometric determination of 0.65–2.62 µg ml–1 of hydrazine. The method has been successfully applied to the determination of hydrazine in water using simple, non-toxic and inexpensive chemicals. The molar absorptivity of the complex is 4.2 × 104 l mol–1 cm–1 for the spectrophotometric procedure. The proposed method has a relative standard deviation of 0.51%, a confidence limit (95%) for 13.000 µg of hydrazine (20 determinations) in solution of 12.985 ± 0.031 and a Sandell sensitivity of 7.63 × 10–4µg cm–2. The determination is free from interferences from a large number of foreign substances.

Residue determination of hydrazine in water by derivatization and gas chromatography

A method is described for the determination of hydrazine residue in water. Hydrazine is converted to the acetone azine, which is extracted with methylene chloride and determined by gas chromatography using a nitrogen/phosphorus detector. The limit of detection is 0.1 part per billion (10 9), and the recoveries ageraged 92% for water fortified with 0.1 to 10 parts per billion of hydrazine. The derivatization of trace levels of hydrazine with a large excess of acetone was compared in a predominantly aqueous system and a methanolic system. The derivatization proceeds quantitatively in 53 min in the methanolic system and in less than 2 m in in the aqueous system. Excellent yields of the azine were obtained at ppb levels.