Determination of total tin in canned food using inductively coupled plasma atomic emission spectroscopy

Abstract

Tin is considered to be a priority contaminant by the Codex Alimentarius Commission. Tin can enter foods either from natural sources, environmental pollution, packaging material or pesticides. Higher concentrations are found in processed food and canned foods. Dissolution of the tinplate depends on the of food matrix, acidity, presence of oxidising reagents (anthocyanin, nitrate, iron and copper) presence of air (oxygen) in the headspace, time and storage temperature. To reduce corrosion and dissolution of tin, nowadays cans are usually lacquered, which gives a marked reduction of tin migration into the food product. Due to the lack of modern validated published methods for food products, an ICP-AES (Inductively coupled plasma-atomic emission spectroscopy) method has been developed and evaluated. This technique is available in many laboratories in the food industry and is more sensitive than atomic absorption. Conditions of sample preparation and spectroscopic parameters for tin measurement by axial ICP-AES were investigated for their ruggedness. Two methods of preparation involving high-pressure ashing or microwave digestion in volumetric flasks were evaluated. They gave complete recovery of tin with similar accuracy and precision. Recoveries of tin from spiked products with two levels of tin were in the range 99+/-5%. Robust relative repeatabilities and intermediate reproducibilities were <5% for different food matrices containing >30 mg/kg of tin. Internal standard correction (indium or strontium) did not improve the method performance. Three emission lines for tin were tested (189.927, 283.998 and 235.485 nm) but only 189.927 nm was found to be robust enough with respect to interferences, especially at low tin concentrations. The LOQ (limit of quantification) was around 0.8 mg/kg at 189.927 nm. A survey of tin content in a range of canned foods is given.

Spectrofluorimetric determination of tin in canned foods

“…Manzoori). atomic absorption spectrometry [11][12][13][14][15][16][17], atomic emission spectrometry [18,19] and electrochemical methods [20][21][22][23]. A few spectrofluorimetric methods have also been proposed for the determination of tin [24][25][26][27][28] but most of them have not been applied to the analysis of real samples.…”

Determination of Tin in Canned Foods by Atomic Absorption Spectrometry

“…Techniques that are most commonly used for determining tin are UV/VIS spectrophotometry (Huang et al 1997), X-Ray fluorescence spectrometry (Mino 2006), inductively coupled plasma atomic emission spectrometry (Perring & Basic-Dvorzak 2002) and electrothermal atomic absorption spectrometry (Chiba 1987). In this work, we describe determination of tin by flame atomic absorption spectrometry in various kinds of canned foods.…”

An Inexpensive and Sensitive Method for Speciative Determination of Sn(IV), Sn(II), and Total Sn as Sn(IV) in Selected Beverages by Micellar Improved Spectrophotometry

“…According to EC 1881/2006, maximum limit for tin (in mg kg −1 wet weight) are as follows: (i) 200 mg kg −1 in canned foods other than beverages, (ii) 100 mg kg −1 in canned beverages including fruit and vegetable juices, and (iii) 50 mg kg −1 in baby food (Boogaard et al 2003;Abedi and Ebrahimzadeh 2013). Due to the acidity, presence of oxidizing reagents, food matrix, and storage conditions such as temperature/time, affect the rate of dissolution of tin into canned food and beverage (Perring and Basic-Dvorzak 2002;Sunday et al 2013;Morte et al 2012), the level of tin may be greater than the amounts above. The toxic effects of tin such as nausea, vomiting, diarrhea, abdominal cramps, bloating, fever and headache, and gastrointestinal symptoms begin to appear above these levels (Abedi and Ebrahimzadeh 2013).…”

“…At pH >2, Sn(II) forms Sn(OH) 2 , which has low solubility under anoxic conditions, whereas Sn(IV) presents in form of Sn(OH) 4 under oxic conditions at lower pHs than 8.0 (Kassoufab et al 2013). Tin is widely used for the production of beverage cans in food industry and as a corrosion protective coating component (Perring and Basic-Dvorzak 2002;Boogaard et al 2003). However, the used tin for packaging of food and beverage samples dissolves into the samples depending on the quantity of food ingested and pH, oxidation state, extent of complexation or adsorption, and solubility (Blunden and Wallace 2003).…”