Table 1.
A summary of CYA analytical methods reported in literatures.
| Method | Principle(s) | LCR | MDL | Ref. | |
|---|---|---|---|---|---|
| Colorimetry | CYA reacts with a melamine reagent to produce some turbidity in water that can be measured at a visible wavelength of 420 nm. | 5–50 mg/L | 1.5 mg/L | Downes et al. (1984) | |
| Electrochemical Methods | Differential Pulse Polarography | CYA sample introduced into an electrochemical analyzer without any previous treatment is used for differential pulse polarography and cyclic voltammetry measurements. | 0.06–3.5 mg/L | 0.02 mg/L | Yilmaz and Yazar (2010) |
| CYA sample is introduced into a polarographic analyzer and measurement is conducted using a static mercury drop electrode in three-electrode cell and an Ag/AgCl reference electrode. | 1.29–129 mg/L | 1 mg/L | Struys and Wolfs (1987) | ||
| Mass Spectrometry | Complex Electrospray Mass Spectrometry | CYA is extracted from water through a microscale liquid-liquid extraction, and then injected into an electrospray mass spectrometer through a mass-selective stable association complex for quantification. | 0–40 mg/L | 0.13 mg/L | Magnuson et al. (2001) |
| Gas Chromatography | GC-MS-(SIM) | A GC method using phase-transfer catalysis for simultaneous derivatization, extraction, and preconcentration, subsequent detection was performed using mass spectrometry selective ion monitoring using electron impact. | 0.001–0.045 mg/L | 0.0003 mg/L | Fiamegos et al. (2003) |
| GC-FTD | A GC method using phase-transfer catalysis for simultaneous derivatization, extraction, and preconcentration; subsequent detection was performed using flame thermionic specific detection. | 0.09–4.5 mg/L | 0.027 mg/L | Fiamegos et al. (2003) | |
| GC-MS | After removal of clean-up solvent, CYA was converted to a tert-butyldimethylsilyl derivative and was determined by GC-MS in the selected ion monitoring mode. | 0.4–4 mg/kg | 0.06 mg/kg | Tang et al. (2009) | |
| GC-MS/MS | Injection-port trimethylsilylated derivatization and GC–MS/MS with furan chemical ionization method to determine CYA and MEL. | 1–500 μg/L (CYA) 0.5–500 μg/L (MEL) |
0.5 μg/kg (CYA) 0.2 μg/kg (MEL) |
Tzing and Ding (2010) | |
| Liquid Chromatography | HPLC-UV | The method developed for CYA using HPLC with UV detection at 213 nm and effective pH control of the eluent (95% phosphate buffer: 5% methanol, v/v) within the narrow range of 7.2–7.4. | 0.5–125 mg/L | 0.05 mg/L | Cantú et al. (2000) |
| The method developed for CYA using HPLC with UV detection at 213 nm, employing phenyl columns via maintenance of a pH of 6.7. | 1–100 mg/L | 0.07 mg/L | Cantú et al. (2001) | ||
| The method developed for CYA using HPLC with UV detection at 213 nm, employing porous graphitic carbon columns maintenance of a pH of 9.1. | 1–100 mg/L | 0.02 mg/L | Cantú et al. (2001) | ||
| An ultrasonic extraction method proposed for the determination of CYA in pet food, combining HPLC with UV detection at 214 nm in solutions at pH ≥ 7.5. | 8–4000 mg/L | 2 mg/L | Yu et al. (2009) | ||
| On-line Microdialysis HPLC-UV | A method using hollow-fiber microdialysis sampling coupled on-line HPLC with UV detection at 203 nm for direct determination of CYA and MEL in non-dairy creamer. | 2–100 mg/L (CYA) 0.02–5 mg/L (MEL) |
0.03 mg/L (CYA) 0.001 mg/L (MEL) |
Chao et al. (2011a) | |
| An on-line membrane sampling with microdialysis/HPLC with UV detection method was developed for the simultaneous determination of CYA and MEL in non-dairy coffee creamer. | 0.5–100 mg/L (CYA) 0.01–5 mg/L (MEL) |
0.15 mg/L (CYA) 0.003 mg/L (MEL) |
Chao et al. (2011b) | ||
| LC–MS/MS | CYA is isolated with a graphitic carbon black solid-phase extraction column, residues are separated from matrix using a porous graphitic carbon column, and then analyzed with electrospray ionization using a triple quadrupole mass spectrometer. | 10–1000 μg/kg | 3.5 μg/kg | Karbiwnyk et al. (2009) | |
| LC-MS | The method used diatomaceous earth extraction columns for sample preparation and negative ion electrospray with a cyano column for CYA quantification. | 0–20 mg/L | 0.1 mg/L | Patel and Jones (2007) | |
| Ion Chromatography | IC-UV | The method used an Omnipac PAX-500 column, 28.8 mM sodium hydroxide solution with 3.5% methanol as mobile phase and UV detection at 213 nm for the determination of TOTCy. | 20–240 mg/L | 0.5 mg/L | Debowski and Gerber (1993) |
| IC-UV | The method used an AEC, a phosphate buffer (pH 7) as eluent, and UV detection at 190 nm for the determination of neutral compounds (urea, biuret, melamine, ammeline) and anions (CYA, acetate, formate, chloride, nitrate, etc.) | unavailable | 0.1 mg/L | Koebel and Elsener (1995) | |
| IC-CM | The method used an AEC, a carbonate buffer as eluent, and a CM detector for the determination of CYA and anions (fluoride, formate, nitrite, hydrogen phosphate, sulfate) in milk powder. | 0.1–100 mg/L | 0.083 mg/L | Wang et al. (2010) | |